title: 1-Amino-2-phenylethylphosphonic acid: an inhibitor of L-phenylalanine ammonia-lyase in vitro.
abstract: L(-)-, and D(+)-enantiomers of 1-amino-2-phenylethylphosphonic acid (PheP), a phosphonic analogue of phenylalanine, inhibit the activity of L-phenylalanine ammonia-lyase (EC 4.3.1.5) of potato tuber tissue in vitro. The apparent type of inhibition depends on concentration of PheP; as the concentration of D-PheP is raised from 10(-5) M to 2.5 X 10(-3) M, the type of inhibition shifts from competitive through mixed and non-competitive to uncompetitive. L-PheP exerts either a competitive or mixed-type inhibition at low (10(-6)-10(-5) M) or moderate (5 X 10(-5)-2 X 10(-4) M) concentration. Ki for the concentration range of competitive inhibition were 6.5 X 10(-6) M, 5.3 X 10(-5)M and 1.6 X 10(-5) M for L-, D-, and D,L-PheP, respectively. These Ki values are valid for a relatively narrow range of L-Phe concentration (0.2-4 mM) as L-phenylalanine ammonia-lyase does not follow the Michaelis-Menten kinetics of the reaction.
mesh_terms: D000642:Ammonia-Lyases / Q000037:antagonists & inhibitors*; D007700:Kinetics; D063065:Organophosphonates / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000494:pharmacology*; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010650:Phenylalanine Ammonia-Lyase / Q000037:antagonists & inhibitors*; D010944:Plants; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D063065:Organophosphonates; D009943:Organophosphorus Compounds; D010649:Phenylalanine; C046316:1-amino-2-phenylethylphosphonic acid; D000642:Ammonia-Lyases; D010650:Phenylalanine Ammonia-Lyase