Purification and Properties of Arginase From Human Liver and Erythrocytes

Biochem J. 1978 Nov 1;175(2):449-54. doi: 10.1042/bj1750449.

Abstract

Arginase was isolated from human liver and erythrocytes. The purification procedure used acetone precipitation, heat-treatment, (NH4)2SO4 precipitation, DEAE-cellulose chromatography and gel filtration on Sephadex G-200 in the presence of 2-mercaptoethanol. Both enzymes migrated to the anode at pH8.3 on polyacrylamide-gel electrophoresis. After incubation at pH8.0 and 37 degrees C the purified anionic liver arginase migrated to the cathode on polyacrylamide-gel electrophoresis. It is assumed that the multiple forms of the enzyme reported in the literature are partly artifacts of the purification procedure. The liver arginase showed a mol.wt. of 107000 determined by gel filtration and a sedimentation coefficient of 5.9S. Treatment of the liver enzyme with 0.25% sodium dodecyl sulphate at pH10 demonstrated an oligomeric structure of the enzyme with a mol.wt. of the subunit of 35000. The kinetic properties determined for the purified liver arginase showed an optimum pH of 9.3 and an optimal MnCl2 concentration of 2mM. The Km for L-arginine was 10.5 mM and for L-canavanine 50mM, and L-lysine exhibited a competitive type of inhibition with a Ki of 4.4mM. L-Homoarginine was not a substrate for liver arginase.

MeSH terms

  • Arginase / blood
  • Arginase / isolation & purification*
  • Arginase / metabolism
  • Canavanine
  • Electrophoresis, Polyacrylamide Gel
  • Erythrocytes / enzymology*
  • Humans
  • Isoenzymes / blood
  • Isoenzymes / isolation & purification*
  • Isoenzymes / metabolism
  • Kinetics
  • Liver / enzymology*
  • Male
  • Mercaptoethanol
  • Molecular Weight

Substances

  • Isoenzymes
  • Canavanine
  • Mercaptoethanol
  • Arginase