Characterization of fatty acid elongase enzymes from germinating pea seeds.
In vitro biosynthesis of radioactive arachidate and behenate was observed when microsomal fractions of germinating pea seeds were incubated with exogenous stearoyl-CoA (18:0-CoA) or arachidoyl-CA (20:0-CoA) in the presence of NADPH, [2-14C]malonyl-CoA and ATP. Characterization of parameters required for optimal stearoyl- and arachidoyl-CoA elongation revealed that, at least, two chain-length-specific elongases are necessary for very-long-chain fatty acid synthesis. Both enzymes were found to be sensitive to the group-selective reagents, p-CMB, NEM, iodoacetate, arsenite and phenylglyoxal. Subcellular fractionation studies indicated that both of these elongases were localized mainly in the endoplasmic reticulum.
School of Molecular and Medical Biosciences, University of Wales Cardiff, U.K.
P B
PB
Barrett
J L
JL
Harwood
D000214:Acyl Coenzyme A / Q000378:metabolism; D051080:Acyl-Carrier Protein S-Malonyltransferase; D000217:Acyltransferases / Q000378:metabolism*; D002250:Carbon Radioisotopes; D007700:Kinetics; D018532:Pisum sativum / Q000201:enzymology*; D013379:Substrate Specificity; D013439:Sulfhydryl Reagents / Q000494:pharmacology
D000214:Acyl Coenzyme A; D002250:Carbon Radioisotopes; D013439:Sulfhydryl Reagents; D000217:Acyltransferases; D051080:Acyl-Carrier Protein S-Malonyltransferase