Purification and Properties of L-Arabinose Isomerase from Streptomyces sp

Abstract

L-Arabinose isomerase (L-arabinose ketol-isomerase, EC 5. 3. 1. 4) was demonstrated from the L-arabinose-grown cells of Streptomyces sp. which was isolated from sea water. The enzyme was purified by MnCl2 treatment, fractionation by polyethylene glycol and by column chromatographies on Sephadex G-150 and DEAE-cellulose. The purified enzyme was specific only for L-arabinose and the Michaelis constant for L-arabinose was 40mm at pH 7.5. Manganese or cobalt ions were effective for the enzyme activity after dialysis against EDTA. The enzyme activity was inhibited competitively by L-arabitol, ribitol and xylitol, of which inhibition constants were 1.1, 1.0, and 15mm, respectively.