Photoaffinity labeling of acyl-coenzyme A:glycine N-acyltransferase with p-azidobenzoyl-coenzyme A.
A photolabile reagent, p-azidobenzoyl-CoA, has been synthesized and tested as a photoaffinity label for acyl-CoA:glycine N-acyltransferase (EC 2.3.1.13) from beef liver. p-Azidobenzoyl-CoA is an active-site-directed reagent for this N-acyltransferase, since it is an alternate substrate (Km = 26 micronM, when [glycine] = 100 mM). Ultraviolet irradiation of a mixture of p-azidobenzoyl-CoA and the N-acyltransferase produces irreversible inhibition. Benzoyl-CoA protects the enzyme from inhibition by photoactivated p-azidobenzoyl-CoA. Acyl-CoA:glycine N-acyltransferase is composed of a single polypeptide with a molecular weight of about 35 000. Photolabeling experiments show that there is one active site per molecule of enzyme.
D000217:Acyltransferases / Q000378:metabolism; D000345:Affinity Labels; D000818:Animals; D001386:Azides / Q000494:pharmacology; D001565:Benzoates / Q000494:pharmacology; D002417:Cattle; D003065:Coenzyme A / Q000031:analogs & derivatives; D005998:Glycine; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D008970:Molecular Weight; D011485:Protein Binding; D013056:Spectrophotometry, Ultraviolet
D000345:Affinity Labels; D001386:Azides; D001565:Benzoates; D000217:Acyltransferases; D003065:Coenzyme A; D005998:Glycine