Journal of Protein Chemistry

, Volume 13, Issue 2, pp 195–215

Contribution of unusual Arginine-Arginine short-range interactions to stabilization and recognition in proteins

Authors

  • A. Magalhaes
    • Departamento de Quimica, Faculdade de CienciasUniversidade do Porto
  • B. Maigret
    • Laboratoire de Chimie TheoriqueUniversité de Nancy-1
  • J. Hoflack
    • Marion-Merrell-Dow Research Institute France
  • J. N. F. Gomes
    • Departamento de Quimica, Faculdade de CienciasUniversidade do Porto
  • H. A. Scheraga
    • Baker Laboratory of ChemistryCornell University
Article

DOI: 10.1007/BF01891978

Cite this article as:
Magalhaes, A., Maigret, B., Hoflack, J. et al. J Protein Chem (1994) 13: 195. doi:10.1007/BF01891978

Abstract

Although the majority of the ion pairs found in proteins consists of two charges of opposite sign, the observation of some unusual arrangements of two arginines led us to a search of such occurrences in the Brookhaven Protein Data Bank. We have found 41 Arginine-Arginine interactions with a Cζ...Cζ distance less than 5 å. Computer graphics analysis of these structures shows that most of the Arg-Arg pairs are found in the vicinity of the surface of the proteins, in an easily hydrated region. In order to determine which factors could stabilize such arrangements of species of similar charge, we have carried out AM1 semi-empirical calculations on a model of two guanidinium ions surrounded by several water molecules. The results show the existence of stable clusters with six or more water molecules, with distances between Cζ atoms around 3 å. The bridging role of the water molecules is an important structural and energetic feature and we find bridges of two and three molecules between the guanidinium ions. These results are in good agreement with the structures found in our search of the experimental data. Enhancement of the electrostatic potential around these clusters, when compared to one of the guanidinium ions alone, is also demonstrated.

Key words

Arginineguanidiniumion-pair interactionssolvationelectrostaticsemi-empirical

Copyright information

© Plenum Publishing Corporation 1994