Coulomb energies of protein-protein complexes with monopole-free charge distributions.
From an analysis of Coulomb energy distributions of a large set of protein-protein complexes we show that the positive tail in the energy distribution disappears when the monopole-monopole term, the only energy term independent of inter-subunit orientations, is removed. This indicates that unfavorable Coulomb energies associated with subunit orientations are excluded in protein-protein complexes. The overall result remained unchanged when solvent effects were included. Our results have important bearing on the restriction of subunit orientations in protein-protein complexes and complement a recent work [K. Brock, K. Talley, K. Coley, P. Kundrotas, E. Alexov, Optimization of electrostatic interactions in protein-protein complexes, Biophys. J. 93 (2007) 3340-3352.] which showed that Coulomb energy of interaction in protein-protein complexes is sequence-optimized.
Das
Madhurima
M
Bioinformatics Centre, Bose Institute, P-1/12 CIT Scheme VIIM, Kolkata 700054, India.
Basu
Gautam
G
D008956:Models, Chemical; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D011506:Proteins / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D055672:Static Electricity
D011506:Proteins; D012997:Solvents