Modelling CamSeq

Conformational analysis is becoming a widely utilized tool in drug design, molecular modeling, and the determination of structure-activity relationships. Of the many techniques presently available for conformational studies, classical, empirical potential energy functions hold great promise in providing relatively inexpensive explorations of conformational hyperspace in various simulated solvent environments. An excellent example of the application of these classical techniques is embodied in the CAMSEQ Software System (1,2.,3.). 

Solvation effects are an important aspect of conformational studies involving biologically important molecules. CAMSEQ/M utilizes a modified hydration shell model to account for these environmental effects (3,9,11,15). Several simulated solvent environments may be calculated. These include aqueous, 1-octanol... 

CAMSEQ/M provides the user with the capability to input complete molecular structures from the internal (disk) data base, to input cartesian or crystallographic coordinates, or to use a "joystick" controlled model-building system. In addition, a molecule may be constructed from one or more substructures with substituents attached using the joystick model-builder routines. Data input is therefore quite flexible, and the user is guided through every step by the program. 

Figure 4 illustrates the "standard" model generated by CAMSEQ/M. This structure may be saved for later use, and/or be used as an input structure for a conformational study. The structure may later be used as a substructure for studying other congeners, by modifying its substituents. For example, amphetamine may easily be constructed by adding the alpha-methyl group to the ethylamine sidechain. The stereochemistry of the molecule is determined by the order of input of the substituents. 

Hopfinger and Battershell developed a semiempirical program, CAMSEQ, with the aim of attempting to make a solvent-dependent conformational analysis and calculating logP values on a whole-molecule basis. For simplicity of calculation, methanol was chosen as a model solvent, and it... 

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