Title | Cathepsin L: a predominant heat-activated proteinase in arrowtooth flounder muscle. |
Publication Type | Journal Article |
Year of Publication | 2001 |
Authors | Visessanguan, W, Menino, AR, Kim, SM, An, H |
Journal | J Agric Food Chem |
Volume | 49 |
Issue | 5 |
Pagination | 2633-40 |
Date Published | 2001 May |
ISSN | 0021-8561 |
Keywords | Animals, Cathepsin L, Cathepsins, Chromatography, High Pressure Liquid, Cysteine Endopeptidases, Endopeptidases, Flounder, Hot Temperature, Hydrogen-Ion Concentration, Molecular Weight, Muscle, Skeletal, Peptide Hydrolases, Substrate Specificity |
Abstract | Characterization of the autolytic profile of arrowtooth flounder (ATF) muscle indicated the involvement of heat-activated proteinases active at both acidic and alkaline pH values. Further assay of fish extract exhibited the maximum activity at 60 degrees C against casein used as a substrate at both pH 5.5 and 8.0. The maximum activity shifted to lower temperatures by the addition of urea with two distinctive patterns: activity reduction at pH 5.5 and activity enhancement at pH 8.0. The highest inhibition by E-64 indicated the proteinase belongs to the cysteine proteinase class. At pH 5.5, the proteinase hydrolyzed Z-Phe-Arg-NMec and all types of protein substrates tested at higher rate than that at pH 8.0. Activity bands, observed on the activity-stained substrate gels, indicated similar proteinases are responsible for the proteolytic activity observed at both pH values. When proteins of fish extract were separated by HPLC-SEC, only one proteolytic peak was observed at the retention time of 26 min with an estimated molecular weight of 39800 Da. The results implied cathepsin L is a predominant proteinase responsible for autolysis of ATF muscle at elevated temperatures. |
Alternate Journal | J. Agric. Food Chem. |
PubMed ID | 11368647 |