New Coenzymically‐Active Soluble and Insoluble Macromolecular NAD + Derivatives

Abstract
Reaction in dimethyl sulfoxide of nicotinamide 8-bromoadenine dinucleotide with the disodium salt of 3-mercaptopropionic acid afforded nicotinamide-8-(2-carboxyethylthio)adenine dinucleotide. a new NAD+ analogue functionalized at the adenine C-8 position by an ω-carboxylic side chain. Carbodiimide coupling of the latter derivative to high-molecular-weight water-soluble (polyethyleneimine, polylysine) and insoluble (aminohexyl-Sepharose) polymers gave the corresponding macromolecular NAD+ analogues. These derivatives have been shown to be enzymically reducible. The polyethyleneimine analogue showed a substantial degree of efficiency relative to free NAD+ with yeast alcohol dehydrogenase (47%) but a considerably lower one with rabbit muscle lactate dehydrogenase (3%); the polylysine analogue showed a low degree of efficiency with both enzymes (5 – 6 %).