Solvent accessibility properties of complex proteins

AN important factor in the thermodynamics of protein folding is the partition of amino acid residues between the solvent environment and the protein core. The extent of the interaction between the folded polypeptide and the surrounding medium can be measured by determining the solvent accessible surface area as defined by Lee and Richards1. In this communication we present the results of solvent accessibility calculations for the large (195,000 Mr) dimeric enzyme phosphorylase a and other multidomain, multisubunit proteins. These results are discussed in the light of the generalisations concerning protein solvent—accessible surface area and shape which have been based on data derived from low molecular weight proteins.