Preparation of coenzymic activity of soluble polyethyleneimine-bound NADP+ derivatives.
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.
D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D001665:Binding Sites; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D007700:Kinetics; D008722:Methods; D009249:NADP / Q000031:analogs & derivatives*; D011094:Polyethyleneimine; D011095:Polyethylenes; D013056:Spectrophotometry, Ultraviolet
D011095:Polyethylenes; D009249:NADP; D011094:Polyethyleneimine; D007521:Isocitrate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D000445:Aldehyde Oxidoreductases; D005969:Glutamate Dehydrogenase