Self-assembly of myosin in vitro caused by rapid dilution. Effects of hydrogen ion, potassium chloride, and protein concentrations.:Effects of Hydrogen Ion, Potassium Chloride, and Protein Concentrations

J-STAGE
  • MIYAHARA Michinori
    Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo
  • NODA Haruhiko
    Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo

この論文をさがす

説明

The in vitro assembly of rabbit skeletal myosin was studied by flow birefringence. Filaments were obtained from a solution of myosin in 0.5M KCl by rapid dilution to lower ionic strength. In most cases, the filament length as determined from extinction angle measurements increased or decreased gradually for about 1h after dilution, depending on pH, KCl concentration and the previous history. The filament length (l) immediately after dilution also showed a marked dependence on pH, KCl concentration and protein concentration (c) at the moment of assembly. The general characteristics obtained from our limited study (0.04-6.0mg/ml) show three distinctive modes of effect of the protein concentration on the filament length: d logl/ d log c is positive (0.1-1) at small c, negative (from -1 to -0.2) at intermediate c, and zero or slightly positive (0.0-0.3) at large c. Lowering of the KCl concentration (75-250mM) as well as increase of the hydrogen ion concentration (pH 6-8) influenced the filament length in qualitatively the same manner as increase of the protein concentration. A model of the assembly reaction of myosin in which the polarity of filaments is crucial was constructed and shown to give qualitatively the experimental dependence of the filament length on the protein concentration.

収録刊行物

詳細情報 詳細情報について

問題の指摘

ページトップへ