ATP:citrate Lyase of Rhodotorula Gracilis: Purification and Properties

Biochim Biophys Acta. 1990 Jan 29;1033(1):23-30. doi: 10.1016/0304-4165(90)90189-4.

Abstract

ATP:citrate lyase was purified from the oleaginous yeast Rhodotorula gracilis to homogeneity as judged by polyacrylamide gel electrophoresis, using a novel citrate-Sepharose procedure. The enzyme was found to have a molecular weight of 520,000 and consisted of four identical subunits (Mr = 120,000). Two minor low molecular weight bands were observed on SDS-PAGE (Mr 51,000 and 49,000). Trypsin digestion experiments indicated that these could have been the result of limited proteolysis by an endogenous trypsin-like proteinase. In this respect, it resembles the mammalian ATP:citrate lyase. The enzyme was stimulated by NH+4 ions and inhibited by palmitoyl, lauroyl, oleoyl, myristoyl and stearoyl-CoA esters, glutamate and glucose 6-phosphate but not by acetyl-CoA or shorter chain fatty acyl-CoA esters. The enzyme exhibited normal Michaelis-Menten kinetics for citrate; however there was a 3-fold increase in Km with a high concentration of Cl- ions (0.25 M). The possible regulatory roles of ATP:citrate lyase in R. gracilis are discussed in the light of these findings.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Citrate (pro-S)-Lyase / antagonists & inhibitors
  • ATP Citrate (pro-S)-Lyase / isolation & purification*
  • ATP Citrate (pro-S)-Lyase / metabolism
  • Acyl Coenzyme A / pharmacology
  • Adenine Nucleotides / pharmacology
  • Citrates / metabolism
  • Citric Acid
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Activation / drug effects
  • Esters / pharmacology
  • Kinetics
  • Macromolecular Substances
  • Mitosporic Fungi / enzymology*
  • Molecular Weight
  • Potassium Chloride / pharmacology
  • Rhodotorula / enzymology*
  • Trypsin

Substances

  • Acyl Coenzyme A
  • Adenine Nucleotides
  • Citrates
  • Esters
  • Macromolecular Substances
  • Citric Acid
  • Potassium Chloride
  • ATP Citrate (pro-S)-Lyase
  • Trypsin