CH...O hydrogen bonds at protein-protein interfaces.
For the first time, a statistical potential has been developed to quantitatively describe the CH.O hydrogen bonding interaction at the protein-protein interface. The calculated energies of the CH.O pair interaction show a favorable valley at approximately 3.3 A, exhibiting a feature typical of an H-bond and similar to the ab initio quantum calculation result (Scheiner, S., Kar, T., and Gu, Y. (2001) J. Biol. Chem. 276, 9832-9837). The potentials have been applied to a set of 469 protein-protein complexes to calculate the contribution of different types of interactions to each protein complex: the average energy contribution of a conventional H-bond is approximately 30%; that of a CH.O H-bond is 17%; and that of a hydrophobic interaction is 50%. In some protein-protein complexes, the contribution of the CH.O H-bond can reach as high as approximately 40-50%, indicating the importance of the CH.O H-bond at the protein interface. At the interfaces of these complexes, C(alpha)H.O H-bonds frequently occur between adjacent strands in both parallel and antiparallel orientations, having the obvious structural motif of bifurcated H-bonds. Our study suggests that the weak CH.O H-bond makes an important contribution to the association and stability of protein complexes and needs more attention in protein-protein interaction studies.
Jiang
Lin
L
State Key Laboratory for Structural Chemistry of Stable and Unstable Species, the Institute of Physical Chemistry, Department of Chemical Biology, College of Chemistry, and the Center for Theoretical Biology, Peking University, Beijing 100871, China.
Lai
Luhua
L
D000595:Amino Acid Sequence; D001665:Binding Sites; D002244:Carbon; D006860:Hydrogen Bonding; D008433:Mathematics; D008958:Models, Molecular; D015233:Models, Statistical; D008962:Models, Theoretical; D010100:Oxygen; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*
D011506:Proteins; D002244:Carbon; D010100:Oxygen