Does phosphoglucoisomerase display anomeric specificity or selectivity towards alpha-D-glucose 6-phosphate? An assessment by two-dimensional phase-sensitive 31P exchange spectroscopy (EXSY) n.m.r.

Abstract

The study by two-dimensional phase-sensitive 31P exchange spectroscopy (EXSY) n.m.r. of hexose 6-phosphates interconversion in the reaction catalysed by yeast phosphoglucoisomerase reveals that the enzyme displays anomeric selectivity, rather than specificity, towards alpha-D-glucose 6-phosphate. Indeed, beta-D-glucose 6-phosphate participates for about 20% to the total and direct conversion of the aldohexose into oxohexose ester.