Appendix B


Appendix C  Common Variables

The following common variables may be examined (the variable name should be preceded by “#” to indicate that it is a THINK common variable, rather than a user-defined symbol):

C.1   Counters

Variable name Description
NTYPES Number of atom types
NMOLES Number of molecules
NATOMS Number of atoms
NFIELD Number of data fields
NTPDUM Number of dummy atom types
NLEARN Number of records in learn file
NFDUSR Start of user data fields (ie read from files)
NTWIST Number of rotatable bonds
NPLTMP Number of temporary pool addresses in use (internal use)
NPHARM Number of unique pharmacophores in molecule
NPDEFN Number of pharmacophore definitions
NRESDS Number of residues
NCYCMX Maximum number of minimisation cycles allowed during ligand refinement in site searches
NITEMX Maximum number of iterations allowed during ligand refinement in site searches

C.2   Constants

Variable name Description See section Default
RCWIDT Current atom label character width    
RCHEIT Current atom label character height    
RRWIDT Requested atom label character width   8.0
RRHEIT Requested atom label character height   12.0
XLPORG X-offset to learn plot origin    
YLPORG Y-offset to learn plot origin    
XLPWID Learn plot column width    
NPTSNG Number of conformational points about single bonds   3
NPTCON Number of conformational points about conjugated bonds   3
NPTALP Number of conformational points about alpha bonds   6
NPTAMD Number of conformational points about amide bonds   0
NPTRNG Number of conformational points about ring bonds   0
ICSAMP Conformational analysis sample size   1000
IFDACT Field containing activity data    
SIGACT Significance value for activity data   0.3
IFDXAX X-axis field for general plot    
IFDYAX Y-axis field for general plot    
IFDZAX Z-axis field for general plot    
RATCPK Ratio of CPK radius to VdW radius   0.6
SCUFTR Display scale factor (pixels per Angstrom)    
NTWUMX Limit to the number of rotatable bonds for conformer generation (0=no limit)   0
RCNFMX Maximum number of conformers for conformer generation (0=no limit) 4.1 0
D3DTOL 3D search distance tolerance   0.5
D3DVOL Ratio of pharmacophore volume to number of heavy atoms   0.25
D3DARE Ratio of pharmacophore area to number of heavy atoms   0.25
I3DHMX Limit to number of substructure solutions considered for 3D search   1000
ISTHMX Limit to number of substructure solutions considered for site search   10000
I3DSUG Number of derivatives to be generated for 3D and site searches   0
GSTMIN Maximum acceptable protein-ligand score for conformer to undergo refinement 8.5 1000
GSTHIT Maximum acceptable score for protein-ligand interactions 8.5 0
IRSEED Random seed   90527531
ICFHMX Maximum number of hits accepted for each conformer (0=no limit) 8.4 0
IMLHMX Maximum number of hits accepted for each molecule (0=no limit) 8.4 0
DSINTR     0
TIMEMX Maximum time for conformational generation during 3D and site searches (minutes)   60.0
RADCEN Overlap between site points and protein atoms (Angstroms) 9.1 0
COZCEN Cosine of minimum permitted angle for accessibility check 9.1 0.5
RADSIT Radius of extended active site (Angstroms) 9.4 8.0
GSITE0 DG0 for conformer score 8.5 -5.48
GSTRES K in contribution to free energy based on fit of conformer to pharmacophore 8.5 1000
GSTHBD DGhbond for conformer score 8.5 -3-34
GSTLIP DGlipo for conformer score 8.5 -0.117
GSTBAD DGbad for conformer score 8.5 0
ITILSZ      
DMNLOS Distance used to allocate distance weightings 3 and 4 to site points 9.5.3 6.0
PSCOMN Minimum acceptable pharmacophore score 9.5.2 10
PSACID Pharmacophore score penalty for acid-HDON matching 9.5.4 0.3
PSBASE Pharmacophore score penalty for base-HACC matching 9.5.4 0.5

C.3   Flags

Variable name Description See section Default
I3DREP Bit 0: Skip hydrogens in intramolecular Ligand energy in scoring function   1
Bit 1: Skip hydrogen interactions in scoring function   2
Bit 2: Reserved   0
Bit 3: Use softer repulsive term in scoring function   0
Bit 4: Site search Simplex systematic vs random start   0
Bit 5: Site search process only best ICFSMX conformers per molecule   32
Bit 6: Reserved   0
Bit 7: Used by CUSTOM RADIUS=[NO]TOLERANCE   128
IMISNG Missing value bit pattern    
ICFSMX Maximum number of best scoring conformers to refine per molecule   100
ICOBGD Background colour for display   15
ICOFGD Foreground colour for display   16
ICOACT Colour for active molecules   4
ICOINA Colour for inactive molecules   2
IDGMOL Update flag for GUI list of molecules    
ICCONT Conformational analysis contacts check (0=ignore; 1=CPK; 2=VdW)   1
ICMODE Conformational analysis search mode (1=systematic; 2=random; 3=sample)   1
IDSMOD Display mode (internal use)    
ILBMOD Atom label options (internal use)    
IDVMOD Diversity display mode (internal use)    
IKYMOD Key display mode (internal use)    
IMKRNG Used for conformer generation of ring coordinates (see code)    
IDSCNF Conformer being displayed    
NDSCNF Number of conformers being displayed    
KDSMOL Pool address of list of molecules being displayed (internal use)    
IQUMOL Query molecule number    
I3DDUM Bit mask controlling calculation of aromatic ring centroids and lipophiles   3
IDSTIL Current molecule display tile    
NDSTIL Number of molecule display tiles    
MDXTIL Number of horizontal tiles in window    
MDYTIL Number of vertical tiles in window    
IREMOT Remote property calculation flag 3.3 0
IUDMOD United Devices mode flag    
NSHITS Number of hits found in the most recent search    
NSTOTL Number of molecules searched in the most recent search    
NPHCEN Number of centres in a pharmacophore   4
NPHBIN Number of pharmacophore distance bins   10
IPHCEN Bit mask of centre types acceptable in pharmacophores   32748
IPHMOD Bit mask controlling pharmacophore calculations   0
IHALT Enables/disables pop-up message box on error    
ISUMOD De novo compatibility flag (=3 for THINK v1.0)   0
ITPACT Bit mask controlling interpretation of activity values   0
ISERVE Client mode flag (internal use)    
ISTALL Save best hit only or all hits during site search (0=best; 1=all) 8.5 0
ITRACE Bit mask controlling production of additional tracing output D 0

Some of these variables may be altered through the LET command. However, it is recommended that the user checks with Treweren Consultants before attempting to modify any common variable, since alteration of some variables (eg the counters) could have catastrophic consequences.


Appendix D