Dehydroxylation/hydroxylation: a novel mechanism for d-allulose 3-epimerase-catalyzed ketohexose epimerization was discovered and validated

Abstract

In response to the disputed dehydrogenation/hydrogenation mechanism of D-allulose 3-epimerase (DAE), this study reveals a dehydroxylation/hydroxylation mechanism via ¹⁸O/²H isotopic labeling in mass spectrometry and DFT calculations, demonstrating metal-coordinated C3–O3 bond cleavage and providing a basis for the rational modification of DAE in rare sugar biosynthesis.