Distribution and complementarity of hydropathy in mutisunit proteins
Article first published online: 3 FEB 2004
Copyright © 1991 Wiley-Liss, Inc.
Proteins: Structure, Function, and Bioinformatics
Volume 9, Issue 1, pages 37–55, January 1991
How to Cite
Korn, A. P. and Burnett, R. M. (1991), Distribution and complementarity of hydropathy in mutisunit proteins. Proteins, 9: 37–55. doi: 10.1002/prot.340090106
- Issue published online: 3 FEB 2004
- Article first published online: 3 FEB 2004
- Manuscript Revised: 6 JUN 1990
- Manuscript Received: 21 SEP 1989
- protein–protein interactions;
- intersubunit binding;
- hydropathy complementarity;
- protein interfaces
A survey of 40 multisubunit proteins and 2 protein–protein complexes was performed to assay quantitatively the distribution of hydropathy among the exterior surface, interior, contact surface, and noncontact exterior surface of the isolated subunits. We suggest a useful way to present this distribution by using a “hydropathy level diagram.” Additionally, we have devised a function called “hydropathy complementarity” to quantitate the degree to which interacting surfaces have matching hydropathy distributions. Our survey revealed the following patters: (1) The difference in hydropathy between the interior and exterior of subunits is a fairly invariant quantity. (2) On average, the hydropathy of the contact surface is higher than that of the exterior surface, but is not greater than that of the protein as a whole. There was variation, however, among the proteins. In some instances, the contact surface was more hydrophilic than the noncontact exterior, and in a few cases the contact surface was as hydrophobic as the protein interior. (3) The average interface manifests significant hydropathy complementarity, signifying that proteins interact by placing hydrophobic centers of one surface against hydrophobic centers of the other surface, and by similarly matching hydrophilic centers. As a measure of recognition and specificity, hydropathy complementarity could be a useful tool for predicting correct docking of interacting proteins. We suggest that high hydropathy complementarity is associated with static inflexible interactions. (4) We have found that some subunits that bind predominantly through hydrophilic forces, such as hydrogen bonds, ionic pairs, and water and metal bridges, are involved in dynamic quaternary organization and allostery.