Quantitative structure-activity relationships and molecular graphics in ligand receptor interactions: amidine...

Quantitative structure-activity relationships have been formulated for four sets of amidine inhibitors of trypsin. The quantitative results from these equations are compared with qualitative models constructed from the X-ray crystallographic coordinates of a benzamidine bound to trypsin. The good agreement between the mathematical and graphics models provides further support for the use of substituent constants and regression analysis in the study of enzyme-ligand interactions.