Kynurenine aminotransferase I activity in human placenta.
The aim of the study was to detect and characterize placental kynurenine aminotransferase I (KAT I) activity in physiological pregnancy at term. Placental KAT I was inhibited by l -glutamine, l -tryptophan, and l -phenylalanine and reached optimum activity at pH 9.8. When pyruvate was used as a co-factor, the KAT I activity was significantly higher than the activity of this enzyme in the presence of 2-oxoglutarate. In the light of our findings placental KAT I seems to have biochemical characteristics of KAT I detected in human brain.
Milart
P
P
Department of Gynecology, Medical University of Lublin, Jaczewskiego 8, PL-20090 Lublin, Poland. milart@eskulap.am.lublin.pl
Urbanska
E M
EM
Turski
W A
WA
Paszkowski
T
T
Sikorski
R
R
D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005973:Glutamine / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007656:Ketoglutaric Acids / Q000494:pharmacology; D007743:Labor, Obstetric / Q000378:metabolism; D008190:Lyases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010649:Phenylalanine / Q000494:pharmacology; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D019289:Pyruvic Acid / Q000494:pharmacology; D000637:Transaminases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014364:Tryptophan / Q000494:pharmacology
D004791:Enzyme Inhibitors; D007656:Ketoglutaric Acids; D005973:Glutamine; D010649:Phenylalanine; D019289:Pyruvic Acid; D014364:Tryptophan; D000637:Transaminases; C427605:glutamine - phenylpyruvate transaminase; C021481:kynurenine-oxoglutarate transaminase; D008190:Lyases