ABSTRACT
A protease involved in oocyte maturation was purified from the ovary of a starfish, Asterias amurensis. Chymotrypsin-like activity of the partially purified 650-kDa protease separated by gel filtration from the ovary extract was inhibited by leupeptin (acetyl-Leu-Leu-argininal) and its five analogs. The inhibitiory potencies of these peptidyl-argininals against the chymotrysin-like activity of the partially purified protease fraction were well in accord with those against germinal vesicle breakdown, suggesting that the protease may be responsible for oocyte maturation. Molecular properties of the purified 650-kDa protease revealed that the enzyme was 20 S proteasome (multicatalytic proteinase complex).
