The proteolytic enzymes in the muscle fluid of Pacific whiting
(Merluccius productus) were studied and compared to those found in muscle
fluid of true cod (Gadus macrocephalus). Preliminary studies indicated
three pH optima of activity for whiting, pH 3.5-3.9, 4.3-4.6 and 7.1-7.2.
Only two pH optima were found for the proteolytic activity of true cod,
pH 3.2-3.6 and 7.7-8.0.
The sarcoplasmic fluid of whiting and cod muscle was studied in
more detail. For both whiting and cod, no hydrolysis of the substrates
hippuryl-L-phenylalanine, hippuryl-L-arginine, α-N-benzoyl-D,L-arginine
p-nitroanilide (BAPA), or toluene sulfonyl arginine methyl ester (TAMA)
at neutral pH's could be detected, indicating the absence of trypsin and
carboxypeptidases A and B. Neither whiting nor cod contained elastase
and only whiting was shown to have activity similar to that of cathepsin
B. True cod was found to contain higher chymotrypsin activity than
whiting at pH 7.15 using the substrate glutaryl-L-phenylalanine
p-nitroanilide. Hydrolysis of the substrate glutaryl-L-phenylalanine
β-naphthylamide (Gly-Phe-2-naphthylamide) from pH 5 to 8 occurred to a
greater extent in Pacific whiting than in true cod.
Various inhibitors and activators were used to characterize the
enzymes in whiting and cod muscle hydrolyzing the substrates GPNA and
Gly-Phe-2-naphthylamide. The responses to the chemicals were compared
with the effects reported in the literature on the hydrolysis of the
substrates by enzymes found in other animal sources. / Graduation date: 1981
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27483 |
| Date | 15 December 1980 |
| Creators | Erickson, Marilyn C. |
| Contributors | Anglemier, Allen F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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