ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Cathepsin B from the skeletal muscle of a fresh water fish Tilapia mossambica was purified 4280-fold with 9% recovery. The electrophoretic homogeneity of the preparation was established both under native and denatured conditions. The molecular weight of cathepsin B on the basis of its gel filtration profile was 23,500 daltons. The enzyme, an endopeptidase, hydrolysed Z-arg-arg-NNap and Bz-arg-NNap, with Km values of 0.57 and 3.23 mM, respectively. Cathepsin B did not display aminopeptidase activity, but cleaved Bz-arg-NH2, exhibiting the specificity of a carboxypeptidase. Among protein substrates tested, only azocoll was hydrolyzed at lower pH values. Leu-peptin, antipain and thiol blockers abolished the enzyme activity completely. The Kcat set-1 value of fish cathepsin B seemed to be lower than that of mammalian enzyme.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1988.tb13521.x
Permalink