Partial Purification and Properties of an AMP-specific Soluble 5'-nucleotidase From Pigeon Heart

Biochem J. 1990 May 15;268(1):117-22. doi: 10.1042/bj2680117.

Abstract

A soluble 5'-nucleotidase was purified 200-fold from pigeon heart. The enzyme (1) had an apparent molecular mass close to 150 kDa, (2) had a neutral pH optimum and hydrolysed a wide range of nucleoside 5'-monophosphates with a 15-fold preference for AMP over IMP, (3) at near-physiological concentrations of AMP was activated by ADP but not by ATP, (4) was inhibited by high Mg2+ concentration and high ionic strength, (5) was weakly inhibited by p-nitrophenol phosphate and Pi, and (6) was non-competitively inhibited more potently by 5'-deoxy-5'-isobutylthioinosine than by 5'-deoxy-5'-isobutylthioadenosine, but not by [alpha,beta-methylene]ADP. The data show that the enzyme is distinct from the ecto-5'-nucleotidase and from the previously purified IMP-specific 5'-nucleotidase. They also predict that the enzyme is activated during ATP catabolism and hence will generate a more-than-linear increase in the adenosine-formation rate in response to an increase in cytosolic AMP concentration.

Publication types

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

MeSH terms

  • 5'-Nucleotidase / antagonists & inhibitors
  • 5'-Nucleotidase / isolation & purification*
  • 5'-Nucleotidase / metabolism
  • Adenosine Diphosphate / pharmacology
  • Adenosine Monophosphate / metabolism*
  • Adenosine Triphosphate / pharmacology
  • Animals
  • Columbidae / metabolism*
  • Enzyme Activation / drug effects
  • Hydrogen-Ion Concentration
  • Inosine Monophosphate / metabolism
  • Kinetics
  • Magnesium / pharmacology
  • Molecular Weight
  • Myocardium / enzymology*
  • Osmolar Concentration
  • Solubility
  • Substrate Specificity

Substances

  • Inosine Monophosphate
  • Adenosine Monophosphate
  • Adenosine Diphosphate
  • Adenosine Triphosphate
  • 5'-Nucleotidase
  • Magnesium