Ion-binding properties of calbindin D9k: a Monte Carlo simulation study

Biochemistry. 1991 May 28;30(21):5209-17. doi: 10.1021/bi00235a014.

Abstract

Monte Carlo simulations are used to calculate the binding constant of two Ca2+ ions to the protein bovine calbindin D9k. The change in binding constant with respect to mutation of charged amino acids, presence of various electrolytes, protein concentration, solution pH, and competitive binding of monovalent ions is investigated. Each of these factors may have a large influence on the binding constant. The simulations are performed in a dielectric continuum model, the so-called primitive model of electrolyte theory, with a fixed protein structure and a uniform dielectric permittivity. The calculated binding constants are in excellent agreement with experimental data and describe changes in the binding constant over six orders of magnitude.

MeSH terms

  • Animals
  • Binding Sites
  • Calbindins
  • Calcium / metabolism*
  • Cattle
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Kinetics
  • Models, Molecular
  • Monte Carlo Method
  • S100 Calcium Binding Protein G / chemistry
  • S100 Calcium Binding Protein G / metabolism*
  • Structure-Activity Relationship
  • Thermodynamics

Substances

  • Calbindins
  • S100 Calcium Binding Protein G
  • Calcium