Biochemical Studies on the Viscera of Cuttle-fish, Ommastrephes Sloani Pacific Us-iii. on the Proteolytic Enzymes of Viscera (part-1)

Few reports have been published regarding the investigation on the enzymes of viscera of cuttle-fish, Ommastrephes sloani pacificus. OSHIMA et a11) have pointed out the existence of proteinase and amylase in the viscera, and NARA2) has investigated on the proteolytic enzy mes of the liver and reported the presence of cathepsin like enzymes. The present paper deals with the proteolytic activity shown by extracts of digestive or gans (stomach, blind sac and intestine, pancreas, and liver) of cuttle-fish. The results are shown in Figs. 1 and 2, Table 1, and summarized as follows: 1) The optimal pH for casein digestion by stomach extract and by extract of blind sac intestine was in the range of 8.0-8.5 and 8.0-8.5, respectively; by pancreatic extract 6.57.0 and 8.0-8.5; by liver extract 2.5 and 5.0-6.0 (Fig. 1). 2) The optimal temperature for casein digestion by the extract of stomach or blind sac intestine was 47.5•Ž at pH 8.0; of pancreas 42.5•Ž at pH 8.0; of liver 40.0•Ž at pH 2.5 and 50.0•Ž at pH 6.0 (Fig. 2). 3) In "unit activity" which refers to the number of proteinase unit per ml. of original extract the blind sac and intestine was the highest among these organs, but the liver was from ten to ninety times higher than the other three organs in "total activity" which is the product of the "unit activity" and weight of the organ (Table 1).