Premium
Purification and Properties of Xylose Isomerase of Streptomyces coelicolor A3 (2)
Author(s) -
Sailaja K.,
Joseph Richard
Publication year - 1993
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19930450904
Subject(s) - xylose isomerase , streptomyces coelicolor , chemistry , xylose , enzyme , acetic anhydride , glucose 6 phosphate isomerase , reagent , streptomycetaceae , cofactor , biochemistry , streptomyces , isomerase , stereochemistry , organic chemistry , chromatography , actinomycetales , fermentation , catalysis , biology , bacteria , mutant , gene , genetics
The xylose isomerase of Streptomyces coelicolor A3 (2) was purified by conventional techniques to apparent homogeneity. The relative molecular mass of the sub‐unit of the enzyme was determined as 40kDa and the enzyme is composed of 4 such sub‐units. Significantly, the enzyme is optimally active at pH 7.0 and at 70°C, and requires only magnesium as cofactor. Presence of magnesium considerably minimizes inhibition of the enzyme by calcium. These considerations suggest that the present enzyme is more ideal for application in high fructose syrup process. The enzyme has Km = 0.041 M for xylose and 0.2 M for glucose with the corresponding V max values being 58.4 and 9.09 mol. min −1 mg −1 . Among the various amino acid modifying reagents, acetic anhydride and ethyl dimethyl amino propyl carbodiimide showed the most pronounced effects of reduction and enhancement of catalysis respectively.