6-Aminonicotinamide and 6-aminonicotinic acid metabolism in nucleated and nonnucleated erythrocytes

• Published in: Archives of biochemistry and biophysics Vol. 88; no. 2; pp. 313 - 317
• Main Authors: Dietrich, L.S., Friedland, Ira M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.1960
• Subjects: 6-Aminonicotinamide; Erythrocytes - metabolism; Niacin - analogs & derivatives; Nicotinic Acids; Nucleosides - blood; Nucleotides - blood; Old Medline; NUCLEOSIDES AND NUCLEOTIDES/blood; ERYTHROCYTES/metabolism; NICOTINIC ACID/related compounds
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/0003-9861(60)90242-3

Incubation of nicotinamide and nicotinic acid with chicken erythrocytes results in an increase of the diphosphopyridine nucleotide (DPN) concentration of the erythrocytes. In contrast with the human erythrocyte, where nicotinic acid is a far better precursor of DPN than nicotinamide, no difference was found in the chicken erythrocyte between nicotinamide and nicotinic acid as precursors of DPN. Acetone powders of human erythrocytes were found to be able to synthesize 6-amino-NMN and 6-aminonicotinic acid mononucleotide from 6-AN and 6-aminonicotinic acid, respectively. 6-Aminonicotinic acid has a high affinity for the enzymic system that converts it to 6-aminonicotinic acid mononucleotide. The affinity of 6-AN for the pathway that produces 6-amino-NMN is very low. No synthesis of 6-aminonicotinic acid-DPN or 6-amino-DPN could be detected in either human or chicken erythrocytes incubated with 6-aminonicotinic acid, even though quantities of 6-aminonicotinic acid mononucleotide accumulated. Incubation of 6-AN with either human or chicken erythrocytes resulted in the formation of small amounts of 6-amino-DPN and 6-amino-NMN. Whether the 6-amino-DPN formed was synthesized from 6-AN directly via DPNase or from 6-amino-NMN cannot be determined from the data.