Effects of protein-protein interactions on electron transfer: docking and electron transfer calculations for complexes between flavodoxin and c- type cytochromes

Carlos A. Cunha, Maria J. Romão, Sheila J. Sadeghi, F. Valetti, G. Gilardi, Cláudio M. Soares

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Theoretical studies of protein-protein association and electron transfer were performed on the binary systems formed by Desulfovibrio vulgaris Hildenborough (D. v. H.) flavodoxin and D. v. H. cytochrome c553 and by flavodoxin and horse heart cytochrome c. Initial structures for the complexes were obtained by rigid-body docking and were refined by MD to allow for molecular flexibility. The structures thus obtained were analysed in terms of their relative stability through the calculation of excess energies. Electrostatic, van der Waals and solvation energy terms showed all to have significant contributions to the stability of complexes. In the best association solutions found for both cytochromes, these bind to different zones of flavodoxin. The binding site of flavodoxin observed for cytochrome c is in accordance with earlier works [27]. The various association modes found were characterised in terms of electron transfer using the Pathways model. For complexes between flavodoxin and horse heart cytochrome c, some correlation was observed between electron tunnelling coupling factors and conformation energy; the best conformation found for electron transfer corresponded also to the best one in terms of energy. For complexes between flavodoxin and cytochrome c553 this was not the case and a lower correlation was observed between electron tunnelling coupling factors and excess energies. These results are in accordance with the differences in the experimental dependence of electron transfer rates with ionic strength observed between these two cases.

Original languageEnglish
Pages (from-to)360-374
Number of pages15
JournalJournal of Biological Inorganic Chemistry
Volume4
Issue number3
DOIs
Publication statusPublished - 1 Jun 1999

Keywords

  • Docking calculations
  • Electron transfer
  • Electron transfer calculations
  • Ionic strength effects in electron transfer
  • Protein-protein interactions

Fingerprint Dive into the research topics of 'Effects of protein-protein interactions on electron transfer: docking and electron transfer calculations for complexes between flavodoxin and c- type cytochromes'. Together they form a unique fingerprint.

Cite this