COENZYME MODELS - 15. A POLYMERIC MODEL SYSTEM FOR THE NADH-DEPENDENT DEHYDROGENASE ENZYMES.

In the reported experiments, copolymers of 4-vinylpyridine (4-VP) and N-(p-vinylbenzyl)-1,4-dihydronicotinamide (VNicH) were synthesized, and a carbonyl substrate (benzil) was reduced to alcohol in an aqueous ethanol solution in the absence and presence of metal ions (Zn**2** plus and Ni**2** plus ) as part of a model study of NADH-dependent enzymes. The reduction rates by VNicH in polymers were four to seven times greater than that of the corresponding monomeric analog (N-benzyl-1,4-dihydronicotinamide). Added metal ions catalyzed the reduction by VNicH-29 (VNicH content, 29 mole%) but inhibited the reduction by VNicH-9 (VNicH content, 9 mole%). It was suggested that metal catalysis occurs only when metal ions are bound closely near the dihydronicotinamide moiety.