Heller JS, Canellakis ES, Bussolotti DL, Coward JK. Stable multisubstrate adducts as enzyme inhibitors. Potent inhibition of ornithine decarboxylase by N-(5'-phosphopyridoxyl)-ornithine.
BIOCHIMICA ET BIOPHYSICA ACTA 1975;
403:197-207. [PMID:
1174545 DOI:
10.1016/0005-2744(75)90022-4]
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Abstract
The synthesis of several N-(5'-phosphopyridoxyl)-amino acids is described. These compounds, analogs of the Schiff base intermediate involved in enzyme-catalyzed decarboxylation, are potent inhibitors of the cognate amino acid decarboxylases. Kinetic studies using partially purified rat liver ornithine decarboxylase, have shown that N-(5'-phosphopyridoxyl)-ornithine inhibits the enzyme in a non-competitive manner with respect to both ornithine and pyridoxal-5'-phosphate. These findings suggest that the inhibitor binds to the holoenzyme active site in place of the Schiff base intermediate.
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