ENANTIOSPECIFIC CHANGE IN PRODUCTS FOR ALDOSE REDUCTASE-MEDIATED REACTION OF GLYCERALDEHYDE WITH BOUND NADP+

Abstract Aldose reductase-mediated reaction of glyceraldehyde with enzyme-bound NADP + gives different products depending on the enantiomer used. D -Glyceraldehyde reacts to form a chromophore (336 nm) similar to the covalent NADP-glycolaldehyde adduct characterized previously [Grimshaw et al. 1990 Biochemistry 29 , 9936–9946]. L -Glyceraldehyde, however, reacts in a slow steady-state process to form an additional chromophore whose spectral properties (λ max 290 nm, e ≈ 16,700 M −1 cm −1 ) suggest that hydration of the nicotinamide 5,6-double bond has occurred. Several mechanisms are proposed to explain this unique stereoisomer-dependent change in reaction pathway.