Concluding remarks

Abstract

For the first time we have been able to interpret the catalytic activity of an enzyme in stereochemical terms. It seems rash to generalize from the structure of one enzyme, but we may broaden our base by elevating myoglobin and haemoglobin to the rank of honorary enzymes, as Monod has suggested, and call the haem groups their active sites. What these three proteins have in common is the distribution of polar and nonpolar side chains; the interior of the lysozyme as well as that of the globin chains is made up largely of hydrocarbons, providing a medium of low dielectric constant. In each case the active centre lies in a pocket formed by this non-polar medium, and the pocket contains some polar residues which are essential for activity.