Soluble uridine diphospho-D-glucose: mycosporin glucosyltransferase from spores of Ascochyta fabae Speg.

The enzyme properties of a soluble uridine 5′-diphosphate (UDP) glucose: mycosporin-2 glucosyltransferase from spores of Ascochyta fabae Speg. (Fungi imperfecti) were studied. The optimal conditions for the glucose transfer from UDP-glucose to the mycosporin-2 (the amide form being the best acceptor) were determined; for maximal activity the glucosyltransferase requires a pH of about 8.5 and the presence of divalent cations (Mn2+ being more efficient than Ca2+ or Mg2+). The reaction was not reversible in presence of large amounts of UDP.