Journal of Protein Chemistry

, Volume 20, Issue 3, pp 203–215

A Study of the Influence of the Hydrophobic Core Residues of Yeast Iso-2-cytochrome c on Phosphate Binding: A Probe of the Hydrophobic Core-Surface Charge Interactions

  • Hiroshi Taniuchi
  • Ying Shi
  • Gloria I. San Miguel
  • James A. Ferretti
  • James W. Mack
  • Alice Fisher
  • Mona Shah
  • Alan N. Schechter
  • Joseph Shiloach
Article

DOI: 10.1023/A:1010906929793

Cite this article as:
Taniuchi, H., Shi, Y., San Miguel, G.I. et al. J Protein Chem (2001) 20: 203. doi:10.1023/A:1010906929793

Abstract

To gain insight into the role of hydrophobic core-surface charge interactions in stabilizing cytochrome c, we investigated the influence of hydrophobic core residues on phosphate binding by mutating residues in yeast iso-2-cytochrome c to those corresponding to iso-1-cytochrome c in various combinations. Heat transition of ultraviolet CD was followed as a function of pH in the presence and absence of phosphate. Thermodynamic parameters were deduced. It was found that the I20V/V43A/M98L mutation in the hydrophobic core, whose locations are remote from the putative phosphate sites, modulates phosphate interactions. The modulation is pH dependent. The I20V/M98L and V43A mutation effects are nonadditive. The results lead to a model analogous to that of Tsao, Evans, and Wennerstrom, where a domain associated with the ordered hydrophobic core is sensitive to the fields generated by the surface charges. Such an explanation would be in accord with the observed difference in thermal stability between iso-2 and horse cytochromes c.

Modulation of phosphate binding influence of hydrophobic core residues electrostatic core-surface interactions polarizable domain model cytochrome c chimeras 

Copyright information

© Plenum Publishing Corporation 2001

Authors and Affiliations

  • Hiroshi Taniuchi
    • 1
  • Ying Shi
    • 1
  • Gloria I. San Miguel
    • 1
  • James A. Ferretti
    • 2
  • James W. Mack
    • 2
    • 3
  • Alice Fisher
    • 1
  • Mona Shah
    • 1
  • Alan N. Schechter
    • 1
  • Joseph Shiloach
    • 4
  1. 1.Laboratory of Chemical BiologyNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda
  2. 2.Center for Advanced Research of BiotechnologyRockville
  3. 3.Department of BiochemistryHoward University College of MedicineWashington, D.C
  4. 4.Laboratory of Cellular and Development BiologyNational Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda

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