- 著者
- Bei-Wei ZHU Lu-Lu ZHAO Li-Ming SUN Dong-Mei LI Yoshiyuki MURATA Lei YU Lei ZHANG
- 出版者
- Japan Society for Bioscience, Biotechnology, and Agrochemistry
- 雑誌
- Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
- 巻号頁・発行日
- vol.72, no.6, pp.1430-1437, 2008-06-23 (Released:2008-06-23)
- 参考文献数
- 36
- 被引用文献数
- 40
Cathepsin L-like enzyme was purified from the body wall of the sea cucumber Stichopus japonicus by an integral method involving ammonium sulfate precipitation and a series of column chromatographies on DEAE Sepharose CL-6B, Sephadex G-75, and TSK-GEL. The molecular mass of the purified enzyme was estimated to be 63 kDa by SDS–PAGE. The enzyme cleaved N-carbobenzoxy-phenylalanine-arginine7-amido-4-methylcoumarin with Km (69.92 μM) and kcat (12.80/S) hardly hydrolyzed N-carbobenzoxy-arginine-arginine 7-amido-4-methylcoumarin and L-arginine 7-amido-4-methylcoumarin. The optimum pH and temperature for the purified enzyme were found to be 5.0 and 50 °C. It showed thermal stability below 40 °C. The activity was inhibited by sulfhydryl reagents and activated by reducing agents. These results suggest that the purified enzyme was a cathepsin L-like enzyme and that it existed in the form of its enzyme-inhibitor complex or precursor.