Subject(s)
Flavin-Adenine Dinucleotide/analogs & derivatives , Polyethyleneimine , Polyethylenes , Apoenzymes/metabolism , Circular Dichroism , D-Amino-Acid Oxidase/metabolism , Enzyme Activation , Flavin Mononucleotide/analogs & derivatives , Glucose Oxidase/metabolism , Methods , Molecular Conformation , Spectrometry, Fluorescence , Spectrophotometry , Structure-Activity RelationshipABSTRACT
Alkylation at N-1 of the NADP+ adenine ring with 3,4-epoxybutanoic acid gave 1-(2-hydroxy-3-carboxypropyl)-NADP+. Enzymic reduction of the latter, followed by alkaline Dimroth rearrangement and enzymic reoxidation, gave N6-(2-hydroxy-3-carboxypropyl)-NADP+. On the other hand, bromination at C-8 of the NADP+ adenine ring, followed by reaction with the disodium salt of 3-mercaptroproionic acid, gave 8-(2-carboxyethylthio)-NADP+. Carbodimide coupling of the three carboxylic NADP+ derivatives to polyethyleneimine afforded the corresponding macromolecular NADP+ analogues. The carboxylic and the polyethyleneimine derivatives synthesized have been shown to be co-enzymically active with yeast glucose-6-phosphate dehydrogenase, liver glutamate dehydrogenase and yeast aldehyde dehydrogenase. The degree of efficiency relative to NADP+ with the three enzymes ranged from 17% to 100% for the carboxylic derivatives and from 1% to 36% for the polyethyleneimine analogues. On comparing the efficiences with the three enzymes of the N-1 derivatives to the one of the corresponding N6 anc C-8 analogues, the order of activity was N-1 greater than N6 greater C-8, except in the case of the carboxylic compounds with glutamate dehydrogenase, where this order was inverted. None of these modified cofactors were active with pig heart isocitrate dehydrogenase.
Subject(s)
NADP/analogs & derivatives , Polyethyleneimine , Polyethylenes , Aldehyde Oxidoreductases/metabolism , Binding Sites , Glucosephosphate Dehydrogenase/metabolism , Glutamate Dehydrogenase/metabolism , Isocitrate Dehydrogenase/metabolism , Kinetics , Methods , Spectrophotometry, UltravioletABSTRACT
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 omega-carboxylic side chain. Carbodimide coupling of the latter derivative to high-molecular-weight water-soluble (polyethyleneimine, polylysine) and insoluble (aminohexy)-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%).
