title: Characterization of a novel hatching enzyme purified from starfishAsterina pectinifera.
abstract: Hatching enzyme is a protease which can degrade the membrane of egg. In this study, a hatching enzyme was purified from starfish (Asterina pectinifera) with 6.34 fold of purification rate, 5.04 % of yield, and 73.87 U/mg of specific activity. The molecular weight of starfish hatching enzyme was 86 kDa, which was reduced to 62 kDa after removal of N-linked oligosaccharides. The optimal pH and temperature of the hatching enzyme activity were pH 7.0 and 40 °C, respectively, while those of stability were pH 8 and 20 °C. The kinetic parameters,Vmax,Km, KcatandKcat/Kmvalues were 0.197 U/ml, 0.289 mg/ml, 112.57 s-1, and 389.52 ml/mg s, respectively. Zn2+increased the enzyme activity by 167.28 %, while EDTA, TPCK, TGCK, leupeptin, PMSF, and TLCK decreased. In addition, Ca2+, Mg2+, and Cu2+did not affect the enzyme activity. The starfish hatching enzyme activity pretreated with EDTA was recovered by Zn2+. Therefore, the starfish hatching enzyme was classified as a serine-zinc protease.
authors.affiliation: Department of Marine Food Science and Technology, Gangneung-Wonju National University, 7 Jukheon-gil, Gangneung, 25457 Republic of Korea.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Marine Food Science and Technology, Gangneung-Wonju National University, 7 Jukheon-gil, Gangneung, 25457 Republic of Korea.
authors.forename: Sang Moo
authors.initials: SM
authors.lastname: Kim
keywords: Asterina pectinifera; Deglycosylation; Hatching enzyme; Purification; Serine-zinc protease; Starfish