SeeSAR: what's new?

version 5.6

  • This new version of SeeSAR comprises another milestone in the evolution of our lightweight 3D modeling package, namely its ability to manage multiple protein structures simultaneously. Oftentimes, you may need to take account of multiple, related protein structures, perhaps either to identify the differences while aiming to achieve specificity, or – just the opposite – to find commonalities, such as when you are trying to ensure all variants of a protein will likely be inhibited. In this first implementation of the multi-protein feature, it is not yet possible to align protein structures but it is necessary to work with pre-aligned structures.
  • Loading multiple proteins
    Loading a protein does not now start a new project, but instead the new protein is simply added to a table of loaded proteins. In order to visualize the binding of ligands from the protein file, first select the protein of interest and then select one of the ligands listed in the table. As before, any of these bound ligands can be copied to the molecules table with a click on the molecule icon in the ligand table row.
  • Handling multiple proteins
    By default, the proteins chains are colored according to the same coloring scheme as before, with each chain in a different color. In the protein table you may set a unique color for a protein to ease identification that will be used for all components of that protein. If you edit a protein, the edited version of the protein will simply be appended to the table without overwriting the original. It is of course also possible to delete proteins from the table. Finally, you may choose the protein to be used for defining a common binding site from the table, just click the icon to start the binding site definition. Once a common binding site has been defined, a little binding site icon indicates which protein was used. Note that only this particular protein is used for the generation of poses, as well as for optimization and affinity estimation, i.e. the Hyde atom coloring on molecules is shown with respect to this protein.
  • Viewing multiple proteins
    Once a common binding site has been defined on one protein, the binding site itself is shown in greater detail. Now however, the regions of the other proteins in the vicinity of the common binding site are also shown in greater detail. This allows you to see the detail you need when seeking out differences or commonalities but the view may, however, become a little crowded. An enhanced menu under the protein visualization icon allows you to switch on and off different protein components (secondary structure, binding site amino acids, ligands, waters and metals) individually or as a group, and you may also change the visibility of entire proteins at once, all making handling of the view very flexible depending on your needs.
  • Other improvements
    We have fixed some seldom occurring but still irritating issues with the 3D editor and also implemented the possibility to restrict the number of CPUs that SeeSAR may recruit for its computation on the command line. On windows, check --help to get an overview of all command line options. The option --thread-count allows you to limit the number of parallel compute threads as best suited. This feature is particularly useful if you run SeeSAR on a cluster which is controlled by a batch queuing system.

version 5.5

  • Shinier and speedier overall!
    Besides a load of novel features (cf. below) behind the scenes, SeeSAR has been given quite a bit of a boost! You will notice a speedier start, faster response times and - most noticeable of all - real time scrolling even if you have loaded thousands of molecules in your table. Note that several of the new features require an update of the underlying databases and therefore necessitate the re-calculation of Hyde scores from older SeeSAR project files!
  • 2D browsing featuring in-view molecule properties
    To further enhance the 2D browsing, we have added an illustration of the molecules' key properties in the form of a radar plot. A thumbnail of the plot is embedded in each of the 2D molecule pictures, providing a quick overview. it enlarges upon mouse-over and provides access to the configuration dialog. Add or remove property-axes, optionally fine-tune the scales and set 'desired' value ranges. A hit or miss of the latter is indicated by green or red dots on the corners of the color-coded characteristic shape of the molecule on the plot (the greener the better).
  • Detecting novel/unoccupied binding sites
    Now SeeSAR can search your protein for unoccupied pockets based on the world-renown DoGSite-Algorithm. You may then select these to become the binding site, within which to generate poses and calculate binding affinities for your molecules. The new binding site definition feature lets you either use a selected molecule from the table (based on a 6.5Å shell around it, as before) or will detect and visualize empty pockets for you to select instead.
  • Multiple reference molecules
    The reference molecule in SeeSAR always stays in view even when you select other entries from the molecule tables. Now, however, you are able to set - and keep in view - as many reference molecules as you like. Either set them individually - in the selected molecule menu (as before) - or mark several as favorites and set them all as references at once, via the new menu button below the table.
  • Multiple core replacements with just one click
    With the new multiple solutions button for ReCore in the molecule editor, brainstorming new scaffold ideas became yet easier. You can now generate 10 new alternative core replacements at once. The new molecules are saved directly to the table so that you can immediately see their estimated binding affinity and view all structures in 2D at a glance.

version 5.4

  • 2D molecule browsing - time to look at things from a different angle!
    While the molecule table offers great functionality for prioritizing compounds based on the data, it does not provide an overview of the molecules themselves. This release, however, sees the introduction of 2D molecule browsing. The table now offers two views - the one you already know and a 2D browser - flick between them using the switch below the table. Both views are always kept in sync so if you add a filter or sort etc. the 2D browser will show you the same result in the same order as the table. Also try expanding the table area to see how more molecules fit into the view.
  • Fantastic new 3D graphics features
    This release also brings with it some great new 3D graphics improvements. As much as we all like visualising the binding site surface, it lay often times in the way… The binding site surface can now be switched to transparent allowing you to see through it and therefore making the analysis of the binding site and molecules within much more comfortable. Also, the feeling of depth in the 3D view has been improved to help orientation - a so-called "fog effect" fades out the protein and molecules that are further away to bring the foreground more into focus.
  • Persistent amino acid labels and better view of reference
    So far, labels on binding site components unfortunately disappeared when browsing through different molecules in the table. Now amino acid, co-factor and water labels remain present if you change to a different molecule in the 3D view and even if you enter the molecule editor. The view of the reference compound has also been improved. For better visibility, the thickness of the bonds has been increased and instead of coloring the whole molecule in a uniform blue color, only the carbon atoms are colored blue so that hetero atoms can be distinguished more easily.

version 5.3

  • Think 2D in the 3D molecule editor!
    The molecule currently visible in 3D is also shown in a 2D representation below. Now in the editor the 2D representation is actually interactive - if you hover to highlight or click to select in 2D, the same will happen simultaneously in 3D and vice versa, giving you a quick and simple overview of the bonds and atoms currently selected ready for editing. This is especially useful for selecting a core fragment (e.g. lasso-style!) for the ReCore scaffold replacement feature.
  • Tweak your molecule conformation by hand in the editor
    Let's assume you made a major change to a molecule in the editor, for example by adding several atoms in a row, and the default positioning of the new fragment is not be optimal. Instead of finding yourself at a dead end, you can now adjust torsions in the editor: simply select a bond and then rotate either side of the bond to optimize the conformation within the context of the active site. While you rotate, the torsion coloring feature will guide you to avoid statistically unlikely states.
  • Key information from a PDB file at hand
    The PDB header contains a lot of unstructured / free text information. The items deemed of most importance are now extracted and shown in the lower part of the protein table tab. In a brief overview, you will find useful information such as the DOI, resolution, and a list of the components along with links to the primary data sources.
  • SeeSAR has a new, more flexible licensing scheme
    Previously, licenses for SeeSAR were issued with a fixed computer processor ID. Now server licenses are also available, meaning users can use SeeSAR from any computer that has access to the license server and are no longer restricted to working on the computer with the licensed processor ID.
  • Text label visibility improved
    You will no longer lose your text labels and 2D molecule representation if you change your background color to white (useful for presentations via LCD-projector)! If the chosen background color is brighter than a certain threshold, the color of the labels and 2D picture now switches automatically to maintain good contrast.

version 5.2

  • Discover the next ReCore features integrated into SeeSAR
    ReCore now takes the binding site into consideration when selecting new core fragments. Clashing as well as duplicate fragments are eliminated so that you will always see fresh ideas in the list. The new installation dialog offers you much more flexibility for installing a ReCore index file. It lets you download index packages from a dedicated website or load your own ReCore index file from disk. You trigger the installation either from the ReCore menu in the editor or via the Settings in the menu bar.
  • Simplify binding mode visualization
    Sometimes the 3D view of the binding mode can be quite busy. Especially if you are preparing a picture for publication or other reporting it is desirable to focus on the essential parts. Now you can fine tune which components of the binding site are shown in the 3D view with just a couple of clicks using the new sequence dialog in the visualization panel (top center). Note that this dialog is available only if a binding site has been selected for the molecule table. If you have calculated the estimated affinity already, you can show H-bonded residues with just one click.
  • Color coded protein surface
    This feature has been requested by many users and becomes reality with the new version. By default the surface is uni-colored but with a gradient according to the depth of the pocket. Alternatively you may select coloring by element or coloring by hydrophilicity based on the atom-specific logP values used for the Hyde affinity assessment (yellow means hydrophobic and blue the level of hydrophilicity).
  • Other improvements
    Now also the 2D picture of the currently edited molecule is available.

    Some use-cases require hiding or eliminating all unwanted molecules at once. To this end we enhanced the favorites filter to also filter the 'non-favorites'. So you can select all favorites => then hide them all => and delete all others.

    Another minor annoyance was that the not-scored molecules always stayed in the way. Now if you filter to see only those compounds with an estimated affinity above a threshold we automatically filter out also all the not-scored compounds.

version 5.1

  • Now it's simple to rename your molecules
    Double-click on the molecule to type in a new name - this is particularly useful for renaming the results of molecule editing.
  • Access your files and recent downloads more easily with the centralized loader
  • Molecule annotation now only one click away
    The molecule annotation is now directly accessible with one click on the triangle mark to the left of the table rows. Mouse-over shows you your annotations while a click opens a small editor to edit them.
  • Core replacement preview
    Many of you will already know our award winning software ReCore. This release includes a sneak preview of the upcoming ReCore integration into SeeSAR. As this is only a preview release, you will need to carry out a few steps of preparation in order to discover its benefits:

    (1) Download and save it to the folder or directory where SeeSAR is installed.

    (2) Unzip the package into the same folder.

    In the editor, you can see the new ReCore button in the menu. Once you have selected a core fragment in your molecule - it must have 2, 3 or 4 non-ring bonds to other fragments - the button will become active and you can click it. One click shows you the best geometrically fitting fragment from the library, another click will show you the next and so on. You can find more details about the sneak preview feature here.

version 5.0

  • This new version brings together several new features designed to give you more control over how you interact with SeeSAR and to speed up browsing in 3D. This means that a new project version is necessary - but here you may find the new project recovery feature useful! Major new features include the new protein ligands, molecules and editor tables plus the editor itself has seen great improvements in user friendliness. Finally, don't miss the new editor feature for editing covalently bound molecules.
  • Neater molecule management with the new protein and molecules tabs
    The molecules table has now been given its own tab and is complemented by a new protein tab. This currently contains the protein ligands table showing the ligands loaded from your PDB file, while the table in the molecules tab is the molecules table you are already familiar with - having all the features previously found in SeeSAR such as filtering, calculating binding affinity with Hyde, pose generation etc. The editor has also been given its own fully interactive table to show the results of your last edits. Read more in the description of the new editor features below.
  • Edit, browse, and edit again - and even edit covalently bound ligands
    As promised we have now added more features for covalently bound ligands. In SeeSAR 5.0 you can edit covalently bounds ligands just like any other molecule or ligand. First add your ligand to the molecules table and then you can select it for editing. Once you are working in the editor, you can take the time to view the results of your edits complete with Hyde atom coloring in 3D. To go back to editing, simply click continue on the edit menu.
  • A new binding site definition for comparability and speed
    While the tables in the two tabs have the same look and feel, there are some slight differences. The protein ligands table shows you the binding affinity for all ligands in their binding sites as loaded from the PDB. However, to calculate the binding affinity or generate poses for molecules in the molecules table, you must first define a unique binding site. This binding site will be used for all molecules in the table, making the comparison of molecules that lie within the binding site more accurate - with the added bonus of greatly accelerating browsing in 3D. Currently the binding site can be defined really simply by choosing any molecule in either table as a starting point. The binding site then remains valid for all molecules in the molecules table until you decide to change your definition. The new binding site definition means that the estimated binding affinities calculated with the previous version of SeeSAR will now be incompatible with the new version and so they must be re-calculated. But SeeSAR can help you recover older projects - read on to find out more!
  • Recover projects saved with the previous SeeSAR version
    A major release includes major changes that mean older projects can no longer be loaded exactly as they were. However, SeeSAR now has new project recovery feature which will load as much data as possible from projects created with the previous version of SeeSAR. Any missing data can then be re-calculated with just a couple of clicks.

version 4.2

  • Control of Hyde affinity calculations handed to user
    Until now, SeeSAR automatically triggered the Hyde affinity calculations. This could be a long process, particularly when loading a large set of molecules from file, or after making an alteration in the Protein Definition dialog. Now, control is handed over to you the user to decide when the calculation should be triggered. This means large sets of molecules can now be loaded, analyzed and processed (e.g. filtering, calculating properties) before the intensive affinity calculations are run. You can trigger the affinity calculations just for a selection of molecules, for example, or even just for individual molecules in the Molecules table.
  • Enhanced filter features
    The collapse and expand buttons (formerly found below the Molecules table) have now been transformed into a filter feature. This feature groups together identical molecules (identified by their unique SMILES), leaving just the molecule with the best estimated affinity as the representative - which is what was previously described as 'collapsing' and was triggered using the collapse button. Also, previously the collapsing or grouping action was always applied before the filters - which was not made apparent with the buttons. Now, this filter is always the last applied. This is clear as the filter is always to the last one shown in the filter panel.
  • Other improvements
    On Windows, there was no output from SeeSAR when using the commandline interface - using the commandline on Windows was like flying blind! Just start 'seesar' on the commandline rather than 'seesar.exe' and the problem will be fixed. 'seesar --help' will give you more help getting started.

    You can also export the protein ligands when using the commandline interface with the new option '--score-protein-ligands'. This is particularly useful if you need to analyse many protein-ligand complexes.

    Covalently bound ligands are now optimized during the Hyde affinity calculation. This allows for a more reliable estimated affinity and is consistent with the treatment of all other molecules. Watch out for more covalent ligand features in following versions!

    Finally, you may now load SD files of molecules into SeeSAR that contain many SD properties. SeeSAR will load the properties up to a maximum amount, whereas previously it was not able to load these files at all.

version 4.1

  • User-defined visualization settings
    Up until now, the 3D view settings were optimized for the current scenario, i.e. when you loaded a protein from file or project it was shown in overview, while after selecting a molecule, the view was focused in more detail on the binding site, ... This was quite comfortable - particularly for first-time users - but at the same time limited your freedom to choose your own viewing preferences. As of version 4.1, the user is back in charge. The optimized settings are still shown to start with but now you can choose to show or hide the following:

    • Hyde coloring for the selected molecule
    • torsion coloring for the selected molecule
    • whole protein
    • surface for the binding site of the selected molecule
    • unoccupied space in the binding site of the selected molecule
    • all waters in the binding site of the selected molecule

    The controls can be found in a panel above the 3D view on the main tool bar. There were previously some switches scattered about in different places in SeeSAR to control some of the these view settings - these have now disappeared having been replaced by the cleaner, less cluttered interface in the new panel.
  • Annotating molecules
    Many users have requested the option to add comments to specific molecules. We have now implemented this as a new feature that can be accessed via the notepad icon for the currently selected molecule in the table. A sticky note is opened where you can enter your comments for this molecule as free-form text. The annotations are saved along with the user name of the author. Molecules with annotations are indicated in the table by a yellow marker at the top left of the row in the molecule table. If you move the mouse over the marker, the annotation appears as a tool tip making it easy to quickly scan through all the notes in the table. These notes are saved to the project allowing you to keep your ideas and thoughts for later, or also to share them with others.
  • Enhanced project handling
    As of version 4.1, SeeSAR will now remind you to save your project if you have unsaved changes before you close SeeSAR or start a new project (either by choosing "New" or "Load" from the Project menu). You now also have the option to "Export" the raw data from your current project to a folder or directory of your choice. This will include the PDB file for the protein, all loaded molecules and any molecules you created using the editor.

version 4.0

  • Major release
    This update of SeeSAR qualifies as major release 4, as several milestones have been achieved with it - namely the integration of the world-reknowned ADME property calculator from Optibrium ™, the display of the protein surface in the 3D view, and an update of the Hyde scoring function. Collectively, these changes have made an update of the SeeSAR storage mechanism necessary, so unfortunately old project files cannot be loaded with this version. We recommend you save your molecules from old projects to file and re-read them with this new SeeSAR version. As an additional bonus feature we implemented the multi-selection of favorites with a simple [Shift] and click. Just try it out, it works as you would expect.
  • Optibrium
    As of version 4.0, SeeSAR is equipped with an interface that allows you to benefit from Optibrium's ADME property calculator from within SeeSAR. Any molecule loaded or edited is passed on to the property calculator, which itself applies multiple computational models to determine a variety of ADME properties. By default you'll see:

    • logP
    • logD @ pH7.4
    • logS (thermodynamic, intrinsic aqueous solubility)
    • logS @ pH7.4 (in phosphate buffered solution)
    • Blood-brain barrier penetration (log([blood]:[brain])
    • hERG inhibition (pIC50)
    • CYP2C9 affinity (pKi)
    • Human intestinal absorption (HIA) classification
    • Blood-brain barrier penetration classification
    • CYP2D6 affinity (pKi) classification
    • Plasma-protein binding classification
    • P-gp transport classification

    However, if you have additional models (within the Optibrium framework) you can add those too and have the respective values available at your fingertips. Note that the usage of this feature requires a separate license!
  • Protein surface
    The binding site of a protein is oftentimes quite complex making it easy to lose the sense of depth, space and tightness of fit. The protein surface of the binding site is now available to aid with orientation and can be toggled on and off very simply using a switch underneath the molecules table. This way, it is easy to switch between the surface view to find the orientation when you need to and the atom-only view at other times.
  • HYDE update
    Hyde is quite sensitive with regards to the numerical stability of the calculation, which we have significantly improved with this update. We also detected a small inaccuracy in the way the coverage of interactions is calculated which has now been corrected. Overall Hyde now has a higher hit rate with respect to the experimental data for high-quality structures and on average avoids overestimating the affinities, i.e. it now provides a more conservative estimate thereby reducing the rate of false positives.

version 3.3

  • Considering individual water molecules (watch this!)
    One of the particular strengths of the Hyde scoring function (and therefore SeeSAR) is its estimation of the effect of water. The whole concept of Hyde is based on the balance of desolvation and interaction. However, as always, the exception defines the rule: Namely, what is true on average for bulk water may be different for individual water molecules. For this reason, Hyde by default explicitly considers water molecules that are particularly tightly bound. Of course, the default may sometimes miss a water that is of particular interest, or take too many into account by including a water that might not be all that stable. Therefore, we have enhanced the Protein Definition dialog so that the user can now have the final say on which waters should be considered and which should be ignored.
  • Assessing covalently bound ligands (watch this!)
    Hyde is much liked for its visualization of the individual atom contributions to the overall binding affinity. This version also allows such visual assessment of covalently bound ligands. They are now listed in the Molecules table together with reversibly bound ligands and co-factors. As with all the other small molecules, a focussed view showing the individual atom contributions to binding is shown in 3D when the covalently bound ligand is selected in the table. We don't, however, provide an overall binding affinity for covalently bound ligands since it is meaningless in this context. Editing of covalently bound ligands is currently disabled but is planned as a feature for a later version.

version 3.2

  • Utilizing SeeSAR without a protein
    SeeSAR has grown from a single purpose affinity assessment tool to a multi purpose 3D structural viewer for compound design and prioritization. With this update it is now also possible to use all these nice features for 3D ligand-based projects. You may, for example, visually inspect small molecules alignments. You may filter a hit list by means of calculated and external properties...
  • Big data booster
    With version 3.0 we first equipped SeeSAR with database functionality. Version 3.2 comes with a load of performance enhancements that speed up the calculation by up to a factor of 5, now utilizing all available CPUs in your computer even more efficiently.
  • 3D graphics enhancement
    In this version we updated the graphics support and SeeSAR is now compatible with more graphics cards than ever before. Especially the compatibility with integrated graphics cards (the type most frequently found in laptop computers) - which used to be the major trouble makers - has been greatly improved.

version 3.1

  • Working with "big data"
    With this update we lifted the limit of handling only a maximum of 5000 poses in SeeSAR. We know that a lot of people like to do their compound analysis and prioritization after virtual screening campaigns also with much bigger sets. It is not likely that you will look at more than a couple of hundred poses, however, since the filtering (see also below) is extremely efficient, it provides quite an attractive opportunity to load all your data (not just the top x) and do your prioritization with all properties at hand right here in SeeSAR.
  • Enhanced filtering
    Behind the scenes SeeSAR knows so much more about your compounds than what is displayed in the table. The basic stuff like no. of acceptors and donors, rotatable bonds, etc. to do the usual Lipinski-type filtering is of course available, but also more elaborate stuff like the number of hydrogen bonds formed or the number of torsions that lie outside the statistical "norm". All of these are now available for filtering to help you optimally trim down your data to find the really interesting part.
  • Older project files invalid
    Please NOTE: SeeSAR project files from older versions are incompatible and cannot be loaded. By default SeeSAR puts a new version in a separate location. So your old version should still be there. If you happen to have lost the old version, read here what you can do about it.

version 3.0

  • Major release
    This update of SeeSAR qualifies as major release 3, since it covers two milestones in its development. So far every SeeSAR session has started from scratch. The only way to retain molecules was to save them to file and re-load them again in a subsequent session. Needless to say that loading meant recalculating all Hyde scores again...
  • Project files
    Starting with Version 3.0, SeeSAR allows you to store all session data in a project file. This includes the protein, ligands loaded from file and new (edited) ligands. Resuming your work on a project is now as easy as double-clicking on the project file. As a result, everything just got a hell of a lot faster! Whilst calculating Hyde-scores for say 1000 compounds took around half an hour (depending on your hardware), loading the same information from a project file now takes only a few seconds. Note that you can also generate a project file on the command line, allowing you to outsource the calculation of Hyde-scores to a different machine. This enhancement is also a great way to exchange data and ideas with a colleague! Simply store your SeeSAR session as a project file in a commonly accessible location (e.g. a network drive). Your colleague can take a look with just a double-click.
  • Hyde update
    Hyde is quite sensitive with regards to the precise geometry of a binding pose. Even the tiniest difference in a pose can distort an anyway stretched hydrogen bond just so much that it is not recognized anymore - thereby leaving you with a huge desolvation penalty for such atoms, without the gain from the H-bond. This 'sharpness' of Hyde is its greatest strength (for example by highlighting real activity cliffs), but also its greatest weakness (especially if the structure has flaws or is of low resolution). In order to minimize such troubles, we optimize each pose before the Hyde affinity assessment. We improved this optimization significantly. It is now fully flexible and with sharper clash criteria, making it suitable for docked poses as well as edited compounds. All of this as efficient as before, just perfect for interactive use.

version 2.2

  • Solution filter
    Finding interesting solutions in larger sets of compounds has just become much easier in SeeSAR. Compounds can now be filtered based on any available property - allowing you to easily trim down the compound set to the most interesting fraction.
    As before, you can browse through and sort the remaining table entries to further refine your selection. Properties can be those generated by SeeSAR (such as the Hyde affinity assessment, the torsional strain, TPSA, logP, ...) or alternatively properties loaded from an SD file.
  • Joined poses
    We have joined the ligands found in the protein structure, compounds loaded from file and compounds newly generated within the SeeSAR editor into one 'super' table and now provide quick-links to the previous view of only those from a certain origin. This allows you to see in one table the bound ligand as a reference, the project compounds and your last round of designs. You can then select your favorites from the entire table and export these (for example for an upcoming team meeting).

version 2.1

  • Defining the protein
    SeeSAR decomposes the contents of a PDB file into chains, small molecules, waters and ions. Until now, users had to accept SeeSAR's default assignments, which is fine in the majority of cases. However, there is no rule without exception, e.g., the peptide inhibitor which is mistaken as a short chain, the small molecule which is actually a co-factor, or the solvent molecule that should be ignored. With this update, SeeSAR allows you to change these default assignments to better handle these exceptional cases, allowing you to categorize a short chain as a bound ligand, or re-assign a co-factor as a permanent part of the protein. You can also eliminate protein elements altogether.
  • SMILES, PDB and MOL file support
    We equipped SeeSAR with additional molecule readers that broaden the scope of the application. Aside from standard 3D molecule file formats (SDF and mol2), SeeSAR now supports 1D and 2D file formats as well as reading small molecules from PDB format. If no 3D coordinates are given, SeeSAR will calculate a clash-free, low energy conformation on the fly: with the SeeSAR positioning function you can then place such input molecules in the active site of interest. Amongst other things, this feature facilitates the importing of molecules straight from your favourite chemical drawing program and assessing such structures in in the context of your protein of interest.

version 2.0

  • Major release
    This update of SeeSAR qualifies as a major release, since it covers a milestone in its development. So far SeeSAR was able to assess given poses of small molecules in a protein structure. Starting with release 2.0 SeeSAR can also generate poses. Also note that the Hyde affinity assessment behind the scenes has been further improved by a variety of fixes and small changes for the benefit of more stability of the calculations. These changes will have an effect on the computed scores. If you rely on the scores resulting from a specific version of the tool, we recommend you to keep such older versions of the tool in an archive.
  • Pose generation
    SeeSAR assesses the binding affinity based on the given position of the ligand in the active site. New in major release number 2 is the introduction of ligand pose generation directly within SeeSAR. So now you can draw and save a molecule in 2D, load it and have SeeSAR predict both binding poses and the related affinity for those poses. Similarly, if you make a substantial modification to the ligand in the editor, you can now validate the original position by generating new binding poses followed by the affinity assessment.
  • Ring conformation sampling
    Significant conformational changes occasionally occurred when ring atoms were modified, reducing confidence in the Hyde estimated binding affinity. We have overcome this by implementing a conformational sampling of ring systems to identify the closest of all energetically favorable ring-conformations.
  • Stay focused
    Sometimes, the 'big picture' can get lost while browsing and inspecting poses in 3D - users can now reset to a standard orientation by hitting 'Space' on the keyboard or with a click on the center view button in the utilities area (lower right corner in the 3D view).

version 1.6

  • Improved editing
    One key functionality that was missing from our molecule editor was the ability to manually set atomic charges. We trusted the compute engine underneath (ProToss) to identify the most likely state automatically when optimizing the overall hydrogen bonding network. However, there are always exceptional cases that prove the rule. Now the user has the final say in this by being able to set the charge for individual atoms. Also, within the scope of the application the user setting won't be overwritten. Hotkeys '+' and '-' make these changes happen really quickly.
  • Improved table handling
    2D-depiction: a picture says a thousand words... To quickly eyeball a compound of interest in a SeeSAR table we implemented a feature to show the structure upon mouse-over. Picomolar affinity: one of the main applications of SeeSAR is in lead optimization where it is not uncommon to work with extremely potent molecules. These are now better accommodated by an extension of the estimated affinities into the picomolar range. Pose-specific functions close by: your mouse used to travel a fairly long distance from selecting a compound to the bottom of table to either edit, delete or keep a table entry in view. Now, these buttons appear just underneath the selected row. Show/hide multiple table columns: The context menu to add and remove table headers now stays in view for multiple selections and disappears gracefully if you click on anything else in the application.

version 1.5

  • More convenient structure editing
    In order to make structure editing an even more convenient, swift and fun process, we have added a few new features:

    Hotkeys: simply select an atom, then type N to change it to a nitrogen. Obviously this "element change" shortcut works for all one-letter types (C, O, N, S, P, I). Context-menus: simply right-click an atom (or bond) to get the all options to add a new atom (or change the bond type) right there. Draw bonds: simply click & hold on an atom, then drag to a second atom to connect the two with a new bond.
  • Improved table handling
    After a virtual screen or docking run, many users will load multiple poses of each of their molecules and then interactively undertake the crucial steps of visual validation and selection. We improved SeeSAR in this regard with two new features.

    (1) For a better overview, you can now collapse all poses of one molecule to a single, representative table entry. This will be the best Hyde-scoring pose. Obviously you can also reverse this process and expand the table to show all the poses.

    (2) As you go through the table you can mark the poses as favorites that you would like to keep. Following this, you can then choose to export only your favorites.

version 1.4

  • Stereo Graphics
    One of the top features on the wish list was stereo support for polarization hardware. So here it is! To activate stereo mode simply open the settings dialog and check the box for stereo view under Display. You can make adjustments for your eye distance using the slider too. If you use different stereo hardware, please let us know at
  • UX Further Improved
    We have taken time to add some more enhanced user experience (UX) features. The main features are:

    Re-position labels: Labels (activate this feature using the label icon in the utilities box, bottom right) provide useful information when you click on objects in the 3D view. Now you may drag labels to a different location. This is handy for preparing images to include in presentations and for de-cluttering your view.

    Browse ligand table contents without leaving the 3D view: Jump from pose to pose with just a keystroke. Simply use the up/down arrow keys on your keyboard. You can even use the delete key, but watch out as there is no undo yet!
  • Screenshots made easy
    A neat new convenience feature has been added to this version. Simply click on the camera icon in the utilities box (bottom right) and save your picture.

version 1.3

  • 2D visualization of selected ligands
    When things get complicated in 3D, it may help to drop a dimension: You can now check the 2D formula of a ligand at the bottom left - Prerequisite: the ligand must have been selected with a click on the respective table line. If you would still like to exploit the full 3D view, just hover over the 2D sketch and a collapse icon will appear for your convenience. Please note that during editing, the 2D picture will only be updated upon leaving the editor (shortcut: just press ESC to leave the editor).
  • Work with your own SD properties
    Sort, check, visually correlate your own information stored in the SD files you use: Upon loading ligands via the menu entry (the 'L' icon in the upper left), we parse your information and you can add it to the properties table on demand. Additional SD properties are added by selecting them from the property drop-down icon at the far right of the table header. A mouse-over on the table column headers will display your property's full name. So, if you had, for example, your own favorite solubility predictor write its prediction into the SD file, you will now have the value ready to use in the table.
  • Web settings to comply with corporate environment
    Your corporate security rules may force you to access the internet through a dedicated computer. You can now specify a proxy to make sure SeeSAR remains fully operational. Please note that the information about the latest updates (displayed when you click on Updates in the Information menu - '?' icon) is obtained from our webpage. If you can't access this information, this may be a hint that you need to change your proxy access settings.

version 1.2

  • See torsions color-coded by statistical relevance
    We now color rotatable bonds in a simple traffic light scheme to show you whether your torsion angles are similar to those observed in crystals or not. Please note that this is not an energetic statement but rather a statistical one. You can switch between this view and Hyde coloring by using the toggle switch at the bottom left of the table. The colors have the following meaning: red = seldom, yellow = occasional, green = frequent
  • Show receptor atoms contributing to a Hyde score
    In SeeSAR, the contributions of receptor atoms are projected onto the ligand atoms, i.e. a red ligand atom can be red because a protein atom is 'unhappy'. To find out which receptor atoms contribute to the ligand atom Hyde score, switch on the label for the respective ligand atom using the label functionality in the utilities area (lower right corner in the 3D view), and click on the eye icon to highlight the contributing receptor atoms.
  • Quick, convenient distance measurements
    To speed up measuring several distances from one given atom, you can now view distances with mouseover. Switch on the distance measurement mode using the utilities area (lower right corner in the 3D view), select an atom, and distances to other atoms will appear upon mouseover. If you click on a second atom, the distance measurement will be kept visible permanently.
  • Lipophilic Ligand Efficiency (LLE) - a new property
    We have implemented an approximate LLE as an additional guideline property in the tables. The orientation of the thumb symbol indicates whether the LLE is great, good, fair, mediocre, or poor. The calculation is based on the Hyde estimated binding affinity and atomic logP values. The traditional Ligand Efficiency (LE) is still available; you can toggle both properties on/off (just as for all other properties) by using the selection tool at the far right of the table header.
  • File dialogs now remember your last location
    When you load protein or ligand data, your last chosen directories will be remembered.
  • License expiration alert
    5 days before your license runs out, an alert dialog will appear when you start SeeSAR. Contact us for an extension at
  • New version alert
    When a new version becomes available, SeeSAR will show an alert on the information symbol in the toolbar above right. Click the 'Updates' icon in the information menu to see the new version details. Click on 'Download', or simply go to, and download your new copy from there.

version 1.1

  • Conformers color-coded according to crystal torsions
    For every molecule in a table, a traffic light style flag is now shown. This gives you a feeling for your ligand torsional conformation based on a comparison of the torsions in your molecule with respect to those observed in crystals. Please note that this is not based on energies but on statistical significance. In other words: The more frequently your torsions match those observed in crystals, the more likely the flag will say 'OK.' This is what the color-coding means: green = most torsions are observed frequently, yellow = some torsions are seldom or occasionally observed, red = several torsions are only seldom observed
  • Visualize the 'explorable volume' of your complex
    We implemented a swift visualization of where the tightness of fit can be improved, or where you can avoid the horror vacui in your binding site: While you are in 3D edit mode, white 'fog' will indicate empty space in the binding interface.
  • Multi-file loading
    You can now load multiple ligand input files at once by performing a multi-selection using the Ctrl/Shift/Apple keys.
  • Unified labeling
    Instead of separate labels for Hyde score, atom names, etc., we have now consolidated all this information in a single label per atom. To activate the label, use the label icon in the utilities area in the lower right corner, and click on an atom.
  • Drag and drop license files
    License files (*.lic) received from us can be drag and dropped into a dialog opened from the information menu in the toolbar: Information >> License. This way, licensing SeeSAR becomes child's play!


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