Kinetic Studies on β-Galactosidase Isolated from Apricots (Prunus armeniaca kaisa)

Sadaf Gulzar, Shajrul Amin

Department of Biochemistry, The University of Kashmir, Srinagar, India.

DOI: 10.4236/ajps.2012.35077                

Abstract

β-galactosidase was extracted from apricots (Prunus armeniaca kaisa) and characterized biochemically. Three isoenzymes (β-gal I, β-gal II and β-gal III) were obtained by salt fractionation and ionexchange and Sephadex G-100 column chromatography. β-galactosidase II showed a high ability to hy-drolyze the substrate p-nitrophenyl β-D-galactopyranoside than that of β-galactosidase I and III. The individual peaks showed charge homogeneity as revealed by single band on polyacrylamide gel. The molecular weight of β-gal I, β-gal II and β-gal III as determined by gel filtration was found to be 44.15, 34.70 and 23.71 KDa respectively. The optimum pH for the activity different isozymes was found between 4 and 6. The isoenzymes were determined to be thermally stable upto 40?C. The Km value for β-gal I was 1.85 mM which was higher than that of β-gal II (K_m = 1.7), and β-gal III (K_m = 1.19). The V_max value for β-gal I, β-gal II and β-gal III was found to be 0.52, 0.70 and 0.38 μmole/min respectively.

Keywords

β-Galactosidase; Apricots; Chromatography; Enzyme Kinetics

Conflicts of Interest

The authors declare no conflicts of interest.

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