筋肉アルカリ性プロテアーゼの研究-III

Abstract

The white muscle of 4 species of freshwater fish, 21 species of marine fish and 2 species of mammalia, and the internal organs of carp, Cyprinus carpio were investigated for the distribution of an alkaline protease which hydrolyzes casein at 60°-65°C in the slightly alkaline pH range. The enzymatic activity was found in almost all fish specimens except Salmo gairdneri iricleus, Theragra chalcogramma, Pneumatophorus japonicus japonicus and Sardinops melanosticta. Potent enzymatic activity was found in muscle specimens of the following species Tylosurus melanotus, Tribolodon hakonesis hakonesis, Cyprinus carpio, Carassius carassius, Clupanodon thrissa, Stephanolepis Cirrhifer, Hemiramphus sajori, Leiognathus nuchalis etc. Moderate enzymatic actlvity was also found in those of Engraulis japonica, Seriola quinqueradiata and Trachurus japonicus, the so-called reddish muscle, and dark muscle of carp. The maximal activity of the enzyme in these fish on 60 min incubation was found at 60°C-65°C and pH 7.7-8.1. The enzymatic activity of rat muscle was lower at 60°C, pH 8.0, than that of fish muscle, but no activity was detectable in rabbit muscle. The enzymatic activity was found in the ovary and testis of carp at 65°C, pH 8.2 and their specific activities were 2-4 fold higher than that of white muscle. The molecular weight of testicular protease was found to be the same as that of the enzyme from the white muscle (780, 000).