title: Participation of cathepsin L in modori phenomenon in carp (Cyprinus carpio) surimi gel.
abstract: Cathepsin L (Cat L) in carp (Cyprinus carpio) dorsal muscles was purified and its molecular weight determined by SDS polyacrylamide gel electrophoresis (SDS-PAGE) was 36 kDa. Its optimal temperature and pH were 50 °C and 5.5, respectively. The results of the effects of specific substrates, activators and inhibitors on the enzymatic activity showed that Cat L belongs to the family of cysteine proteinases containing thiol. Compared to the control, the gel strength of surimi with the addition of purified Cat L decreased significantly by 24.33% while that of surimi with both purified Cat L and inhibitors increased by 13.7% and 21.6%, respectively, suggesting the participation of Cat L in the modori phenomenon occurring in carp surimi. Both the SDS-PAGE electrophoretic pattern and microstructure figure revealed that Cat L could hydrolyse the main protein in carp surimi and was one of the enzymes involved in the modori phenomenon.
authors: Department of Food Science and Nutrition, Zhejiang University, Hangzhou 310058, Zhejiang Province, China. yqhu@zju.edu.cn
authors: Yaqin
authors: Y
authors: Hu
authors: Rong
authors: R
authors: Ji
authors: Hai
authors: H
authors: Jiang
authors: Jinjie
authors: J
authors: Zhang
authors: Jianchu
authors: J
authors: Chen
authors: Xingqian
authors: X
authors: Ye
mesh_terms: D000818:Animals; D002347:Carps; D056668:Cathepsin L / Q000737:chemistry* / Q000302:isolation & purification; D004795:Enzyme Stability; D005396:Fish Products / Q000032:analysis*; D029941:Fish Proteins / Q000737:chemistry* / Q000302:isolation & purification; D009132:Muscles / Q000737:chemistry / Q000201:enzymology*; D059748:Proteolysis
chemical_list: D029941:Fish Proteins; D056668:Cathepsin L