title: Inhibition of human placental-type alkaline phosphatase variants by peptides containing L-leucine.
abstract: The inhibition of normal human placental alkaline phosphatase, its rare "D-variant" phenotype, and the "Nagao isoenzyme" found in an ovarian cancer fluid by peptides containing L-leucine were studied. The Nagao isoenzyme and the D-variant phenotype were distinct from the normal placental enzyme, but similar to each other in their inhibition by L-leucine and dipeptides containing L-leucine in their amino termini. On the other hand, L-leucinamide, L-Leu-L-Leu-L-Leu and L-Leu-Gly-Gly inhibitions did not readily discriminate between D-variant and normal phenotypes, but did so between D-variant and Nagao isoenzymes. The distinctions among these enzymes in their responses to peptide inhibitors may reflect differences in their primary structures.
mesh_terms: D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors*; D004151:Dipeptides / Q000494:pharmacology; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D007700:Kinetics; D007930:Leucine / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology*; D010641:Phenotype; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D013329:Structure-Activity Relationship
chemical_list: D004151:Dipeptides; D007527:Isoenzymes; D009842:Oligopeptides; D000469:Alkaline Phosphatase; D007930:Leucine