Distribution of myosinase I and myosinase II in tissues of Coleoidea

We previously reported that novel metallo proteinases, myosinase I and II, which specifically hydrolyzed a myosin heavy chain were purified from squid mantle muscle. In this report, we show the distribution of myosinases in Coleoidea. Spear squid and cuttlefish had myosinase I activity. Japanese common squid had bo th myosinase I and II activity. In the previous report, we showed that myos inases activity was detected only in extract of Teuthoidea mantle muscle. B ut in this research, we detected the myosinases activity not only in mantle but also in other tissues other than ovaries from various species of Coleo idea. Each of the livers contained especially high activity. This results suggest that myosinases hydrolyze other substrates.