Peptide amidating enzymes are present in cultured endothelial cells.
Carboxy-terminal amidation is a prevalent post-translational modification necessary for the bioactivity of many peptides. We now report that the two enzymes essential for amidation, peptidylglycine alpha-monooxygenase (PAM) and peptidylamidoglycolate lyase (PGL), are present in both the cytosol and membrane fractions of cultured bovine aortic endothelial cells. Endothelial PAM exhibits ascorbate-dependent turnover and is inactivated by the mechanism-based inactivator, 4-phenyl-3-butenoic acid (PBA), whereas PGL activity is independent of ascorbate and is not affected by PBA. These enzymological characteristics correspond to those of amidating enzymes from other tissues. These results suggest a heretofore unrecognized role for alpha-amidated peptides in cardiovascular function.
Oldham
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CD
School of Chemistry & Biochemistry, Georgia Institute of Technology, Atlanta 30332.
Li
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C
Girard
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PR
Nerem
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RM
May
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SW
D019760:Amidine-Lyases; D000818:Animals; D001011:Aorta; D001205:Ascorbic Acid / Q000494:pharmacology; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000201:enzymology*; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D007700:Kinetics; D008190:Lyases / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009097:Multienzyme Complexes
D005229:Fatty Acids, Monounsaturated; D009097:Multienzyme Complexes; C064180:4-phenyl-3-butenoic acid; D006899:Mixed Function Oxygenases; C035189:peptidylglycine monooxygenase; D008190:Lyases; D019760:Amidine-Lyases; C068521:peptidylamidoglycolate lyase; D001205:Ascorbic Acid