During the past two decades, interactions between carbohydrates and metal ions awaked a remarkable interest in the field of bioinorganic chemistry, since many sugar-processing enzymes have been discovered to function with alkaline earth (Mg2+ or Ca2+) and divalent transition metal ions (e.g. Zn2+, Cu2+, Co2+, or Mn2+) in the active sites. As displayed in Figure the sugar-metabolizing metalloenzymes comprise isomerases, e.g. phosphomannose isomerase (left) or xylose isomerase, which accelerate the conversion of aldohexoses to the corresponding ketoses.
