Influence of Me2SO and incubation time on papain activity studied using fluorogenic substrates.

M Szabelski; K Stachowiak; W Wiczk

doi:10.18388/abp.2001_3862

Influence of Me2SO and incubation time on papain activity studied using fluorogenic substrates.

M Szabelski Faculty of Chemistry, University of Gdańsk, Poland.;
K Stachowiak
W Wiczk

DOI: https://doi.org/10.18388/abp.2001_3862

Abstract

Papain activity in a buffer containing Me2SO was studied using fluorogenic substrates. It was found that the number of active sites of papain decreases with increasing Me2SO concentration whereas the incubation time, in a buffer containing 3% Me2SO does not affect the number of active sites. However, an increase of papain incubation time in the buffer with 3% Me2SO decreased the initial rate of hydrolysis of Z-Phe-Arg-Amc as well as Dabcyl-Lys-Phe-Gly-Gly-Ala-Ala-Edans. Moreover, an increase of Me2SO concentration in working buffer decreased the initial rate of papain-catalysed hydrolysis of both substrates. A rapid decrease of the initial rate (by up to 30%) was observed between 1 and 2% Me2SO. Application of the Michaelis-Menten equation revealed that at the higher Me2SO concentrations the apparent values of k(cat)/Km decreased as a result of Km increase and kcat decrease. However, Me2SO changed the substrate binding process more effectively (Km) than the rate of catalysis k(cat).

Published

2001-12-31

Issue

Vol. 48 No. 4 (2001)

Section

Articles

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