Enzymology of NAD+ synthesis

Adv Enzymol Relat Areas Mol Biol. 1999;73:135-82, xi. doi: 10.1002/9780470123195.ch5.

Abstract

Beyond its role as an essential coenzyme in numerous oxidoreductase reactions as well as respiration, there is growing recognition that NAD+ fulfills many other vital regulatory functions both as a substrate and as an allosteric effector. This review describes the enzymes involved in pyridine nucleotide metabolism, starting with a detailed consideration of the anaerobic and aerobic pathways leading to quinolinate, a key precursor of NAD+. Conversion of quinolinate and 5'-phosphoribosyl-1'-pyrophosphate to NAD+ and diphosphate by phosphoribosyltransferase is then explored before proceeding to a discussion the molecular and kinetic properties of NMN adenylytransferase. The salient features of NAD+ synthetase as well as NAD+ kinase are likewise presented. The remainder of the review encompasses the metabolic steps devoted to (a) the salvaging of various niacin derivatives, including the roles played by NAD+ and NADH pyrophosphatases, nicotinamide deamidase, and NMN deamidase, and (b) utilization of niacins by nicotinate phosphoribosyltransferase and nicotinamide phosphoribosyltransferase.

Publication types

  • Review

MeSH terms

  • Amide Synthases / metabolism
  • Amidohydrolases / metabolism
  • Animals
  • Humans
  • NAD / biosynthesis*
  • Niacin / metabolism
  • Nicotinamidase / metabolism
  • Nicotinamide-Nucleotide Adenylyltransferase / metabolism
  • Pentosyltransferases / metabolism
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • Pyrophosphatases / metabolism
  • Quinolinic Acid / metabolism

Substances

  • NAD
  • Niacin
  • Pentosyltransferases
  • nicotinate-nucleotide diphosphorylase (carboxylating)
  • Phosphotransferases (Alcohol Group Acceptor)
  • NAD kinase
  • Nicotinamide-Nucleotide Adenylyltransferase
  • Amidohydrolases
  • Nicotinamidase
  • nicotinamidenucleotide amidase
  • Pyrophosphatases
  • Amide Synthases
  • NAD+ synthase
  • Quinolinic Acid