Purification and properties of sn-glycerol-1-phosphate dehydrogenase from Methanobacterium thermoautotrophicum: characterization of the biosynthetic enzyme for the enantiomeric glycerophosphate backbone of ether polar lipids of Archaea

J Biochem. 1997 Sep;122(3):572-6. doi: 10.1093/oxfordjournals.jbchem.a021791.

Abstract

The enzyme which seems to be responsible for the formation of the enantiomeric configuration of the glycerophosphate backbone (sn-glycerol-1-phosphate) of archaeal ether lipids was purified from a methanogenic archaeon, Methanobacterium thermoautotrophicum, and characterized. The enzyme, sn-glycerol-1-phosphate: NAD(P)+ oxidoreductase (sn-glycerol-1-phosphate dehydrogenase), was purified 7,600-fold from a cell free extract by ammonium sulfate fractionation and seven steps of chromatography. The final preparation exhibited a specific activity of 617 micromol/min/mg (Vmax) and gave a single band corresponding to 38 kDa on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The native enzyme showed an apparent molecular mass of 302 kDa on gel-filtration chromatography, indicating it is present as a homooctamer. Maximum activity was observed at 75 degrees C at near neutral pH. The activity was stimulated by potassium ions. The Km for dihydroxyacetone phosphate was 7.5 times smaller than that for sn-glycerol-1-phosphate, suggesting that the formation of sn-glycerol-1-phosphate is the natural direction in the cell. Under the assay conditions used, no product inhibition was observed. The N-terminal amino acid sequence was determined.

MeSH terms

  • Amino Acid Sequence
  • Archaea / enzymology*
  • Bacterial Proteins / isolation & purification*
  • Bacterial Proteins / metabolism*
  • Glycerolphosphate Dehydrogenase / isolation & purification*
  • Glycerolphosphate Dehydrogenase / metabolism*
  • Glycerophosphates / biosynthesis
  • Kinetics
  • Methanobacterium / enzymology*
  • Methanobacterium / metabolism
  • Molecular Sequence Data
  • Phospholipid Ethers / metabolism*
  • Stereoisomerism
  • Substrate Specificity

Substances

  • Bacterial Proteins
  • Glycerophosphates
  • Phospholipid Ethers
  • Glycerolphosphate Dehydrogenase