Rat intestinal nucleotide-sugar pyrophosphatase. Localization, partial purification, and substrate specificity

J Biol Chem. 1985 Jun 25;260(12):7474-80.


The nucleotide-sugar pyrophosphatase activity of rat small intestine was studied using GDP-[14C]Man as substrate. The highest specific activities in the gastrointestinal tract were in the proximal small intestine, with a preferential localization in villus tip cells. Purified brush-border membranes were highly enriched in nucleotide-sugar pyrophosphatase. After the enzyme was solubilized with detergent and purified 180-fold, it hydrolyzed FAD and p-nitrophenyl-5'-thymidylate, as well as nucleotide sugars. That the same enzyme, a 5'-nucleotide phosphodiesterase, is responsible for nucleotide-sugar pyrophosphatase, phosphodiesterase I, and FAD pyrophosphatase activities is indicated by: co-migration in electrophoresis, parallel thermal inactivation, competitive inhibition studies, and similar regional, cellular, and subcellular localizations.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Colon / enzymology*
  • Gastric Mucosa / enzymology*
  • Intestinal Mucosa / enzymology*
  • Intestine, Small / enzymology*
  • Kinetics
  • Male
  • Microvilli / enzymology
  • Organ Specificity
  • Pyrophosphatases / isolation & purification*
  • Pyrophosphatases / metabolism
  • Rats
  • Solubility
  • Substrate Specificity


  • Pyrophosphatases
  • nucleoside-diphosphosugar pyrophosphatase