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Partial purification and characterization of chinook salmon (Oncorhynchus tshawytscha) calpains and an evaluation of their role in postmortem proteolysis

Author:
Geesink, G.H., Morton, J.D., Kent, M.P., Bickerstaffe, R.
Source:
Journal of food science 2000 v.65 no.8 pp. 1318-1324
ISSN:
0022-1147
Subject:
Oncorhynchus tshawytscha, peptidases, proteolysis, postmortem changes, muscles, cold storage, refrigeration, enzyme activity, casein, sheep, myofibrils
Abstract:
The involvement of calpains in the proteolysis of salmon muscle during refrigerated storage was investigated. Salmon m-calpain and mu-calpain were purified and partially purified, respectively. Salmon m-calpain had similar calcium requirements and specific activity against casein as ovine m-calpain. Salmon mu-calpain had similar calcium requirements as ovine mu-calpain but a lower specific activity against casein than ovine mu-calpain. Autolysis patterns of both calpains differed from those of ovine calpains, and their activities were less than those of mammalian muscles. Calpastatin activity was relatively high and comparable to that of bovine muscles. Little proteolysis and fiber fragmentation resulted during refrigerated storage. However, proteolysis could be reproduced by incubation of myofibrils with m-calpain.
Agid:
1395117