pubmed.ncbi.nlm.nih.gov

Studies on activation and inhibition of cathepsin B from buffalo liver - PubMed

Studies on activation and inhibition of cathepsin B from buffalo liver

A Salahuddin et al. J Protein Chem. 1996 Jan.

Abstract

Cathepsin B (EC 3.4.22.1) was purified from buffalo liver. The enzyme activity against alpha-benzoyl-DL-arginine-naphthylamine (BANA) was substantially reduced by heat (above 37 degrees C) and by nondenaturing concentrations of urea (3 M) and guanidine hydrochloride (1 M). Cathepsin B was significantly activated by 1.5 mM EDTA alone. The activation of the enzyme was further enhanced in the presence of thiol compounds, e.g., cysteine thioglycolic acid, 2,3-dimercapto-1-propenol, and dithioerythritol (DTE). The minimum concentration of the thiol compound required for optimal activation of cathepsin B was found to be lowest (0.2 mM) for DTE. The BANA hydrolyzing activity of cathepsin B was substantially reduced by Cu2+ (20-200 microM) and Ca2+ (30-250 mM) as well as by thiol blocking reagents, e.g., iodoacetate, 5,5'-dithiobis(2-nitro-benzoic acid) (DTNB), and p-hydroxymercuribenzoate (pHMB). The enzyme activity was completely abolished when the molar ratio of the reagent: cathepsin B was close to 1. The number of free sulfhydryl groups in cathepsin B was determined to be 2 by titration against DTNB and pHMB. Modification of one free thiol group of cathepsin B resulted in complete loss of BANA hydrolyzing activity.

PubMed Disclaimer

Similar articles

References

    1. Proc Natl Acad Sci U S A. 1986 May;83(9):2909-13 - PubMed
    1. Biochem J. 1982 Jan 1;201(1):189-98 - PubMed
    1. Methods Enzymol. 1981;80 Pt C:535-61 - PubMed
    1. J Biochem. 1980 Dec;88(6):1805-11 - PubMed
    1. Adv Protein Chem. 1968;23:121-282 - PubMed

MeSH terms

Substances

LinkOut - more resources