ヒトデ類のプロテアーゼ活性

Abstract

The proteolytic activity of four species of starfishes, Asterias amurensis, Solaster borealis, Lysastrosoma anthosticta and Asterina pectinifera, was compared using their crude enzyme extracts.All the starfishes examined showed high proteolytic activity in pyloric caeca, but very weak activity in the gonads and other organs. The activity level (units/mg) in pyloric caeca varied with species. The crude enzymes from A. amurensis, S. borealis, L. anthosticta and A. pectinifera showed the highest activity at around pH 9.0, 37°C; pH 9.0, 45°C; pH 8.0, 50°C and pH 7.5, 55°C, respectively. The enzymes in the crude extracts of these starfishes seemed to be very stable at the neutral pH. There was a tendency that the crude enzyme showing the highest activity at a relatively high temperature was comparatively thermostable.At least as far as the tested A. amurensis, no difference in proteolytic activity in pyloric caeca was observed before and after spawning.