title: [Identification of a photolabelled site of the plasma binding protein for testosterone and estradiol (SBP) using tritiated 17 beta-hydroxy- 4,6-androstadien-3-one].
abstract: The testosterone-estradiol binding protein (sex binding protein = SBP), immunopurified from human placental blood, was photolabelled by irradiation at lambda greater than 300 mm in the presence of tritiated 17 beta-hydroxy-androsta-4,6-dien-3-one. High-performance reverse-phase liquid chromatography of tryptic peptides, showed two main peaks of radioactivity. Sequence determination of these two fractions indicated that the radioactivity was associated with an undetectable amino-acid preceded either by the sequence His-Pro-Ile (major peak) or Arg-His-Pro-Ile at the N-terminal site and bearing Arg as C-terminal amino-acid. Comparison with the sequence reported for human SBP (K.A. Walsh et al., Biochemistry, 25, 1986, pp. 7584-7590) suggested that radioactive labelling was localized on the Met-139 residue of the hexapeptide Arg-His-Pro-Ile-Met-Arg (fragment 135-140).
mesh_terms: D000345:Affinity Labels; D000595:Amino Acid Sequence; D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments; D010777:Photochemistry; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D013739:Testosterone / Q000031:analogs & derivatives* / Q000378:metabolism; D014316:Tritium; D014357:Trypsin
chemical_list: D000345:Affinity Labels; D010446:Peptide Fragments; D012738:Sex Hormone-Binding Globulin; D014316:Tritium; C023630:6-dehydrotestosterone; D013739:Testosterone; D014357:Trypsin
vernacular_title: Identification d'un site de photomarquage de la protéine plasmatique de liaison de la testostérone et de l'oestradiol (SBP) par l'hydroxy-17 beta oxo-3 androstadiène-4,6 tritié.