title: Fluorescent, photoaffinity, and biotinyl analogs of oxytocin.
abstract: This study reports the solid phase synthesis and biological activities of two oxytocin analogs, [1-desamino, 4-lysine,7-(L-3,4,-dehydroproline)]oxytocin and [1-desamino, 4-threonine,7-(L-3,4-dehydroproline),8-lysine]oxytocin, and several fluorescent, photoaffinity, or biotinylated derivatives of these analogs and of oxytocin. The activities (in IU/mg) of the lysine-containing parent compounds, respectively, were as follows: uterus (without Mg++) 4.8 and 54; uterus (with Mg++) 19 and 440; milk ejection 65 and 414. The above analogs were coupled through the chemically reactive epsilon-amino group of lysine in position 4 or 8 or, in the case of oxytocin, through the N-terminal amino group of fluoresceine, photoaffinity, or biotinyl ligands. Fluoresceine coupled in position 1 of oxytocin gave an analog of low to moderate uterine (3.8 without Mg+ and 1.9 with Mg++) and milk ejection (7.9) activities. Analogs with biotin or fluoresceine coupled to lysine in position 4 had moderate uterine (11 and 23 without Mg++; 38 and 11 with Mg++) and milk ejection (33 and 13) activities. Analogs with fluoresceine, photoaffinity, or biotinyl labels coupled to lysine in position 8 retained good uterine (106, 62, and 147 without Mg++; 79, 78, and 509 with Mg++) and milk ejection (101, 181, and 247) activities and represent potentially useful experimental tools for studying hormone-receptor interactions and for receptor localization and isolation.
authors.affiliation: Department of Physiology and Biophysics, Mount Sinai School of Medicine of CUNY, New York 10029.
authors.forename: A
authors.initials: A
authors.lastname: Buku
authors.forename: N
authors.initials: N
authors.lastname: Yamin
authors.forename: D
authors.initials: D
authors.lastname: Gazis
mesh_terms: D000345:Affinity Labels / Q000138:chemical synthesis* / Q000494:pharmacology; D000818:Animals; D001681:Biological Assay; D001710:Biotin; D005260:Female; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000494:pharmacology; D007202:Indicators and Reagents; D008893:Milk Ejection / Q000187:drug effects; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects
chemical_list: D000345:Affinity Labels; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D010121:Oxytocin; D001710:Biotin