Characterization of mutant β-glucosidase g226e from Anoxybacillusayderensis

Enzymes are biological keys of metabolic pathways. β-glucosidase taking part in methabolic pathways is widespread and associated with all living things. β-glucosidase representing an significant group of glycoside hydrolase family has plenty of natural and artificial substrates. Also, it shows different substarate specificity against these substarates. Therefore, it is important for industrial application. In this study, the enzyme which has already been cloned from Anoxybacillus ayderensis Ay9 was used. Also, this enzyme has already been mutation with N222S. For the purpose of making the second mutation at position 226, glycine was converted to glutamic acid. After that enzyme characterization was performed to investigate the mutation effect on the enzyme by using p-nitrophenyl β-d-glucopyranoside (pNPG) as a substrate. The optimum temperature of enzyme was 50°C and the optimum pH was 7. Kinetic parameters were determined as 0,35 mM, 16,61 U/mg, 14,98 s-1, 42,26 s-1mM-1 for Km, Vmax, kcat ve Km/kcat values, respectively.