抄録
1. Four kinds of myosin B of various extraction time-3 or 10 minutes, 30 minutes, 3 hours and 24 hours-were prepared from the fast adductor muscle of Pecten yessoensis.
2. By extension of extraction time from 10 minutes to 30 minutes or to 24 hours, ATP sentitivity increases twice.
3. Composition of four kinds of myosin B was investigated by salting-out analysis, and it was found that they consist mostly of myosin and actomyosin.
4. Their functional unit weights increase slightly with extraction time.
5. From these results it was concluded that the properties of myosin B are changed by the combination of ATP with the active site
of the myosin molecule.
6. Mg_??_strengthens the combination of ATP at the active site, and Ca_??_weakens the combination.
I wish to thank to Prof. Y. Sakamoto (Department of General Education) and Prof. N. Takasugi (Chemistry Department) for their support; to Assist. Prof. Tono-mura (Research Institute for Catalysis) for his warm encouragement and valuable advice. This study has been aided in part by a grant in aid from the Fundamental Scientific Fund of the Ministry of Education given to the Research Group on the “Chemistry of Muscular Contraction”
