Cobalt X-ray absorption spectroscopy of glucose isomerase

Abstract

Introduction Glucose isomerases catalyze the isomerization of D-glucose to D-fructose and of D-xylose to D-xylulose. They are of considerable interest in the industrial production of high-fructose corn syrup. Glucose isomerase from Streptomyces albus (GI) is a tetramer (Mr = 172.000) with four identical subunits [1,2]. Each subunit contains two distinct metal bindin of Co2+, Mn f sites, a tight binding site (B-site) and a weaker binding site (A-site). Addition + or Mg2’ * increases the catalytic activity as well as the stability of the enzyme.