title: Purification and characterization of cocoonase from the silkworm Bombyx mori.
abstract: Cocoonase (CCN) which facilitates the degradation of a cocoon is recognized as a trypsin-like serine protease. In this study, CCN from the silkworm Bombyx mori was purified and comprehensively characterized. Its activity was maximal at about pH 9.8. It was stable above pH 3.4 at 4 °C and below 50 °C at pH 7.5. CuSO₄, FeSO₄, and ZnSO₄ showed inhibitory effects on CCN, but other salts improved activity. Typical trypsin inhibitors inhibited CCN, but the relative inhibitory activities were much lower than those against bovine trypsin. An extract of cocoon shells inhibited trypsin, but it was only slightly inhibitory against CCN. There were significant differences in catalytic efficiencies and substrate specificities as between CCN and bovine trypsin.
authors.affiliation: a Institute of Genetic Resources, Faculty of Agriculture, Kyushu University , Fukuoka , Japan.
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Fukumori
authors.forename: Satoshi
authors.initials: S
authors.lastname: Teshiba
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Shigeoka
authors.forename: Kohji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Banno
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Aso
mesh_terms: D000818:Animals; D012831:Bombyx / Q000201:enzymology*; D002417:Cattle; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D010447:Peptide Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D012492:Salts / Q000494:pharmacology; D013379:Substrate Specificity
chemical_list: D011480:Protease Inhibitors; D012492:Salts; D010447:Peptide Hydrolases
keywords: Bombyx mori; cocoonase; protease; silkworm; trypsin