Effect of cerulenin on the synthesis of very-long-chain fatty acids in microsomes from leek seedlings.
Cerulenin inhibits the elongation of stearoyl-CoA and eicosanoyl-CoA by microsomes from leek seedlings. The inhibition depends on the cerulenin concentration and affects the biosynthesis of docosanoic and tetracosanoic acids only slightly more than that of eicosanoic acid. A 30-min preincubation of the microsomes with cerulenin allows a quantitative inhibition of the elongation at 50 microM cerulenin (50% inhibition at 15 microM cerulenin). A kinetic study of the elongating activity in the presence or in the absence of the inhibitor suggests that the inhibition is non-competitive. Analysis of the products of the reaction suggests that 3-ketoacyl-CoA synthase is the target of cerulenin. A study of the partial reactions demonstrates that the inhibition affects almost exclusively the condensation step.
Schneider
F
F
Institut de Biochimie Cellulaire, CNRS, Bordeaux, France.
Lessire
R
R
Bessoule
J J
JJ
Juguelin
H
H
Cassagne
C
C
D000123:Acetyltransferases / Q000037:antagonists & inhibitors; D000214:Acyl Coenzyme A / Q000378:metabolism; D051080:Acyl-Carrier Protein S-Malonyltransferase; D000217:Acyltransferases / Q000037:antagonists & inhibitors; D002569:Cerulenin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D000081031:Fatty Acid Elongases; D005227:Fatty Acids / Q000096:biosynthesis*; D007700:Kinetics; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology; D010944:Plants / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure
D000214:Acyl Coenzyme A; D005227:Fatty Acids; D002569:Cerulenin; C017725:stearoyl-coenzyme A; D000217:Acyltransferases; D000123:Acetyltransferases; D000081031:Fatty Acid Elongases; D051080:Acyl-Carrier Protein S-Malonyltransferase