title: Asymmetric in vitro synthesis of diastereomeric phosphatidylglycerols from phosphatidylcholine and glycerol by bacterial phospholipase D.
abstract: Using chiral-phase HPLC, we determined the stereochemical configuration of the phosphatidylglycerols (PtdGro) synthesized in vitro from 1,2-diacyl-sn-glycero-3-phosphocholine (PtdCho, R configuration) or 1,2-diacyl-sn-glycero-3-phosphoethanolamine (PtdEtn, R configuration) and glycerol by transphosphatidylation with bacterial phospholipase D (PLD). The results obtained with PLD preparations from three Streptomyces strains (S. septatus TH-2, S. halstedii K5, and S. halstedii subsp. scabies K6) and one Actinomadura species were compared with those obtained using cabbage and peanut PLD. The reaction was carried out at 30 degrees C in a biphasic system consisting of diethyl ether and acetate buffer. The resulting PtdGro were then converted into bis(3,5-dinitrophenylurethane) derivatives, which were separated on an (R)-1-(1-naphthyl)ethylamine polymer. In contrast to the cabbage and peanut PLD, which gave equimolar mixtures of the R,S and R,R diastereomers, as previously established, the bacterial PLD yielded diastereomixtures of 30-40% 1,2-diacyl-sn-glycero-3-phospho-1'-sn-glycerol (R,S configuration) and 60-70% 1,2-diacyl-sn-glycero-3-phospho-3'-sn-glycerol (R,R configuration). The highest disproportionation was found for the Streptomyces K6 species. The present study demonstrates that bacterial PLD-catalyzed transphosphatidylation proceeds to a considerable extent stereoselectively to produce PtdGro from PtdCho or PtdEtn and prochiral glycerol, indicating a preference for the sn-3' position of the glycerol molecule.
authors.affiliation: Graduate School of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan.
authors.forename: Rina
authors.initials: R
authors.lastname: Sato
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Itabashi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hatanaka
authors.forename: Arnis
authors.initials: A
authors.lastname: Kuksis
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D005990:Glycerol / Q000737:chemistry; D007202:Indicators and Reagents; D008722:Methods; D010713:Phosphatidylcholines / Q000737:chemistry; D010715:Phosphatidylglycerols / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification; D010739:Phospholipase D / Q000378:metabolism*; D013237:Stereoisomerism; D013302:Streptomyces / Q000201:enzymology
chemical_list: D001426:Bacterial Proteins; D007202:Indicators and Reagents; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D010739:Phospholipase D; D005990:Glycerol