Computing and Library Services - delivering an inspiring information environment

Interaction energy decomposition in protein–protein association: A quantum mechanical study of barnase–barstar complex

Ababou, Abdessamad, Van der Vaart, Arjan, Gogonea, Valentin and Merz, Kenneth M. Jr. (2007) Interaction energy decomposition in protein–protein association: A quantum mechanical study of barnase–barstar complex. Biophysical Chemistry, 125 (1). pp. 221-236. ISSN 03014622

Metadata only available from this repository.


Protein–protein interactions are very important in the function of a cell. Computational studies of these interactions have been of interest, but often they have utilized classical modelling techniques. In recent years, quantum mechanical (QM) treatment of entire proteins has emerged as a powerful approach to study biomolecular systems. Herein, we apply a semi-empirical divide and conquer (DC) methodology coupled with a dielectric continuum model for the solvent, to explore the contribution of electrostatics, polarization and charge transfer to the interaction energy between barnase and barstar in their complex form. Molecular dynamic (MD) simulation was performed to account for the dynamic behavior of the complex. The results show that electrostatics, charge transfer and polarization favor the formation of the complex. Our study shows that electrostatics dominates the interaction between barnase and barstar ( 73%), while charge transfer and polarization are 21% and 6%, respectively. Close inspection of the polarization and charge-transfer effects on the charge distribution of the complex reveals the existence of two, well localized, regions in barstar. The first region includes the residues between P27 and Y47 and the second region is between N65 and D83. Since no such regions could be detected in barnase clearly suggests that barstar is well optimized for efficiently binding barnase. Furthermore, using our interaction energy decomposition scheme, we were able to identify all residues that have been experimentally determined to be important for the complex formation and to suggest other residues never have been investigated. This suggests that our approach will be useful as an aid in further understanding protein–protein contacts for the ultimate goal to produce successful inhibitors for protein complexes.

Item Type: Article
Subjects: Q Science > Q Science (General)
Q Science > QD Chemistry
Schools: School of Applied Sciences
Related URLs:
Depositing User: Sara Taylor
Date Deposited: 12 Feb 2009 09:26
Last Modified: 28 Aug 2021 10:44


Downloads per month over past year

Repository Staff Only: item control page

View Item View Item

University of Huddersfield, Queensgate, Huddersfield, HD1 3DH Copyright and Disclaimer All rights reserved ©