[The effect of magnesium ions on the two-stage kinetics of superprecipitation and ATPase activity of natural actomyosin]

Biokhimiia. 1990 May;55(5):822-8.
[Article in Russian]

Abstract

The effect of magnesium ions on the two-stage kinetics of superprecipitation (SPP) and ATP activity of natural skeletal muscle actomyosin was studied. It was found that the changes in the ratios of two independent steps of SPP and ATPase activity are mainly induced by the Mg-ATP2- complex, but not by free Mg2+. These changes in the kinetics of SPP and ATPase are regarded as being due to the shift in the dynamic equilibrium between the two types of the actomyosin complexes in solution, each of which is characterized by different reaction mechanisms. The role of the Mg-ATP2(-)-induced alteration of at least two structural-and-functional states of actomyosin in muscle contractibility is discussed.

Publication types

  • English Abstract

MeSH terms

  • Actomyosin / metabolism*
  • Adenosine Triphosphatases / metabolism*
  • Animals
  • Ca(2+) Mg(2+)-ATPase / metabolism
  • Chemical Precipitation
  • Hydrolysis
  • In Vitro Techniques
  • Kinetics
  • Magnesium / pharmacology*
  • Male
  • Muscles / drug effects
  • Muscles / enzymology
  • Muscles / metabolism*
  • Rats

Substances

  • Actomyosin
  • Adenosine Triphosphatases
  • Ca(2+) Mg(2+)-ATPase
  • Magnesium