コイアクトミオシンの加熱によるＳＨ基の挙動

Abstract

In order to clarify the participation of sulfhydryl groups (SH) in the heat-induced gel formation of actomyosin, the effect of heating temperatures up to 80°C on the contents of total SH and reactive SH of carp actomyosin was examined. The total SH was determined in the presence of 8M urea at pH 7.0 by using Ellman's reagent and the reactive SH was done without urea by using the same reagent. The oxidized SH content, which was estimated from the decrement of the total SH content, increased with the rise of temperature above 40°C. When heated at 60°C, the reactive SH content, which seems to be the exposed SH content, was maximum, and the difference in the content between the total SH and the reactive SH, which is taken as the inner SH content, was minimum. The behavior of the reactive SH of the actomyosin with respect to heating temperature is quite compatible with the behavior of the gel forming ability of the actomyosin, which has been reported in the previous paper. It can therefore be presumed that the reactive SH, which appeared on the molecular surface by heating, contributes to the gel formation of actomyosin through some bonding between the protein molecules.