Covalent reaction of cerulenin at the active site of acyl-CoA reductase of Photobacterium phosphoreum.
Inhibition of bioluminescence in Photobacterium phosphoreum by cerulenin has been demonstrated to be due to a specific inactivation of the acyl-CoA reductase subunit of the fatty acid reductase complex required for synthesis of the aldehyde substrate for the luminescent reaction. In contrast, the activities of the other luminescence-related enzymes, acyl-protein synthetase, acyl-transferase, and luciferase, were unaffected by cerulenin. Myristoyl-CoA, but not NADPH, protected the acyl-CoA reductase against cerulenin inhibition. Cerulenin blocked the acylation of the reductase with myristoyl-CoA and the reaction with N-ethylmaleimide. A shift in mobility of the reductase polypeptide on sodium dodecyl sulfate - polyacrylamide gel electrophoresis occurred after reaction with cerulenin, a shift which could be blocked by reaction with N-ethylmaleimide. These results demonstrate that cerulenin blocks aldehyde synthesis by covalent reaction with the acyl-CoA reductase and indicate that the reaction may occur at a cysteine residue involved in the formation of the acyl-reductase intermediate.
Wall
L
L
Department of Biochemistry, McGill University, Montreal, Que., Canada.
Meighen
E
E
D000214:Acyl Coenzyme A / Q000494:pharmacology; D000445:Aldehyde Oxidoreductases / Q000037:antagonists & inhibitors*; D000935:Antifungal Agents / Q000494:pharmacology*; D001665:Binding Sites; D002569:Cerulenin / Q000494:pharmacology*; D005033:Ethylmaleimide / Q000037:antagonists & inhibitors; D008163:Luminescent Measurements; D010776:Photobacterium / Q000187:drug effects* / Q000201:enzymology
D000214:Acyl Coenzyme A; D000935:Antifungal Agents; D002569:Cerulenin; C040349:S-tetradecanoyl-coenzyme A; D000445:Aldehyde Oxidoreductases; C027902:fatty acid reductase; C021351:hexadecanal dehydrogenase (acylating); D005033:Ethylmaleimide