Separation of cathepsin D-like proteinase and acid thiol proteinase of squid mantle muscle.
When the proteinases of the squid mantle muscle were extracted in the presence of dithiothreitol (DTT), the acid proteinase activity increased, indicating that the squid mantle muscle contains a considerable amount of the acid thiol proteinase. The crude extract hydrolyzed neither alpha-N-benzoyl-D,L-arginine-p-nitroanilide (BAPA) nor azocasein, thus refuting the presence of cathepsins B and L in the mantle muscle. The cathepsin D-like proteinase and the acid thiol proteinase were separated by Sephadex A-50 column chromatography. Each of the above partially purified proteinases was able to degrade carp actomyosin at pH 2.5 and 5.0, respectively.
D000205:Actomyosin / Q000378:metabolism; D000818:Animals; D002347:Carps; D002402:Cathepsin D; D002403:Cathepsins / Q000302:isolation & purification*; D055598:Chemical Phenomena; D002621:Chemistry; D003546:Cysteine Endopeptidases; D049832:Decapodiformes / Q000201:enzymology*; D010450:Endopeptidases / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D009132:Muscles / Q000201:enzymology
D000205:Actomyosin; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D002402:Cathepsin D