title: Determination of leucine aminopeptidase using phenylalanyl-3-thia-phenylalanine as substrate.
abstract: The peptide mimetic L-phenylalanyl-L-3-thiaphenylalanine has been shown to facilitate a sensitive and simple determination of leucine aminopeptidase. A colorimetric assay, employing Ellman's reagent to detect the thiophenol released upon hydrolysis of the dipeptide, has been developed. Under the experimental conditions employed the substrate has a Km of 0.054 mM and a kcat of 5800 min-1 and can distinguish sharply between leucine aminopeptidase and aminopeptidase M.
authors.forename: S Y
authors.initials: SY
authors.lastname: Hwang
authors.forename: W D
authors.initials: WD
authors.lastname: Kingsbury
authors.forename: N M
authors.initials: NM
authors.lastname: Hall
authors.forename: D R
authors.initials: DR
authors.lastname: Jakas
authors.forename: G L
authors.initials: GL
authors.lastname: Dunn
authors.forename: C
authors.initials: C
authors.lastname: Gilvarg
mesh_terms: D000626:Aminopeptidases / Q000378:metabolism; D018826:CD13 Antigens; D002863:Chromogenic Compounds / Q000138:chemical synthesis* / Q000378:metabolism; D004151:Dipeptides / Q000138:chemical synthesis* / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D007931:Leucyl Aminopeptidase / Q000378:metabolism*; D013053:Spectrophotometry
chemical_list: D002863:Chromogenic Compounds; D004151:Dipeptides; C049315:phenylalanyl-3-thiaphenylalanine; D000626:Aminopeptidases; D007931:Leucyl Aminopeptidase; D018826:CD13 Antigens