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New method to discriminate between cathepsin B and cathepsin L in crude extracts from fish muscle based on a simple acidification procedure
Author(s) -
Godiksen Helene,
Nielsen Henrik Hauch
Publication year - 2007
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2006.01254.x
Subject(s) - cathepsin b , cathepsin o , cathepsin , chemistry , biochemistry , cathepsin l , substrate (aquarium) , hydrolysis , cathepsin d , enzyme , microbiology and biotechnology , biology , ecology
Summary A new and simple method to distinguish between cathepsin B and cathepsin L in crude extracts of herring ( Clupea harengus ) muscle has been established. An acid treatment of crude extracts (exposed to pH 3 for 5 min) activated a latent form of cathepsin L and inactivated cathepsin B. Furthermore, in neutral crude extract, the hydrolysis of benzyloxycarbonyl‐ l ‐phenylalanyl‐ l ‐arginyl‐4‐methylcoumarine (Z‐Phe‐Arg‐MCA) (cathepsin B and cathepsin L substrates) was between 0% and 15% of the hydrolysis of benzyloxycarbonyl‐ l ‐arginyl‐ l ‐arginyl‐7‐amino‐4‐methylcoumarine (Z‐Arg‐Arg‐MCA; cathepsin B substrate). Cathepsin B activity is measured in neutral extract using the specific cathepsin B substrate Z‐Arg‐Arg‐MCA and cathepsin L activity is measured in acid‐treated extract with Z‐Phe‐Arg‐MCA as substrate. The specific cathepsin B inhibitor, CA‐074, did not inhibit the Z‐Arg‐Arg‐MCA significantly without affecting the Z‐Phe‐Arg‐MCA activity. An acid treatment of the crude extract is therefore a more advantageous approach to discriminate between cathepsin B and cathepsin L activities.