Synthesis and properties of (R)-2-hydroxyglutaryl-1-CoA. (R)-2-hydroxyglutaryl-5-CoA, an erroneous product of glutaconate CoA-transferase.
1) (R)-2-Hydroxyglutaryl-1-CoA was synthesised starting from (R)-5-oxotetrahydrofuran-2-carboxylic acid (gamma-lactone of (R)-2-hydroxyglutarate) which was converted to the acylchloride and condensed with N-capryloylcysteamine. The lactone ring of the resulting thiolester was opened by acid hydrolysis and the CoA derivative was obtained by transesterification. 2) Pure glutaconate CoA-transferase from Acidaminococcus fermentans catalysed the formation of the 1- and the 5-isomer of (R)-2-hydroxyglutaryl-CoA from acetyl-CoA and (R)-2-hydroxyglutarate. The isomers were separated by HPLC and characterised by their reaction with acetate under the catalysis of the CoA-transferase. V/Km for the 1-isomer was 80 times higher than that for the 5-isomer. 3) Studies with cell-free extracts from A. fermentans showed that only (R)-2-hydroxyglutaryl-1-CoA but not its 5-isomer was dehydrated to glutaconyl-1-CoA. The data indicate that (R)-2-hydroxyglutaryl-5-CoA is an erroneous product of glutaconate CoA-transferase which only occurs in vitro.
Klees
A G
AG
Laboratorium für Mikrobiologie, Fachbereich Biologie, Phillips-Universität Marburg.
Buckel
W
W
D000214:Acyl Coenzyme A / Q000138:chemical synthesis* / Q000737:chemistry; D001421:Bacteria, Anaerobic / Q000201:enzymology*; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D015256:Coenzyme A-Transferases / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013237:Stereoisomerism
D000214:Acyl Coenzyme A; C070412:2-hydroxyglutaryl-1-coenzyme A; C070414:2-hydroxyglutaryl-5-coenzyme A; D015256:Coenzyme A-Transferases