| Title: | "Binding of the pheromonal steroid, 5alpha-androst-16-en-3-one, to membrane-enriched fractions of boar and rat olfactory epithelium; preliminary evidence for binding protein being a glycoprotein" |
| Author(s): | Kraevskaya MA; Higgins MJ; Wilson MT; Gower DB; |
| Address: | "Division of Biochemistry and Molecular Biology, United Medical and Dental Schools, Guy's Hospital, London SE1 9RT, UK" |
| Journal Title: | J Steroid Biochem Mol Biol |
| DOI: | 10.1016/s0960-0760(03)00264-4 |
| ISSN/ISBN: | 0960-0760 (Print) 0960-0760 (Linking) |
| Abstract: | "A high degree of binding of 5alpha-[3H]-androstenone was recorded in membrane-enriched fractions of porcine olfactory tissue. The specific (i.e. high affinity, low capacity) binding had a mean Ka approximately 2x10(8)M(-1). A Hill plot of the data showed a Hill coefficient of approximately 2, possibly suggesting co-operativity of binding, with binding constants increasing from 8x10(7) to 1.6x10(9)M(-1) with increasing substrate concentration. The level of specific binding of 5alpha-[3H]-androstenone was nearly 10-fold higher than in corresponding respiratory tissue preparations and was markedly reduced in the presence of excess (approximately 1 microM) unlabelled 5alpha-androstenone. Corresponding fractions derived from rat olfactory tissue showed only 25% of the binding recorded for the pig. After incubation of 5alpha-[3H]-androstenone with solubilised olfactory cilial tissue (porcine), gel filtration and chromatography on a typical 'glycoprotein' column (Concanavalin A-Sepharose B) were performed. Specific binding was recorded only in fractions corresponding to glycoproteins with Mr of approximately 70-90 kDa. In a third series of experiments, fractions containing high concentrations of cilia, some still attached to the dendritic endings (as shown by electron microscopy) were obtained by a novel method involving stripping them off the nasal epithelium. The basal adenylate cyclase (AC) activity was very significantly (P<0.01) higher in olfactory, compared with respiratory, cilia; storage at -70 degrees C for 3 weeks greatly reduced AC activity. When fresh male and female porcine olfactory cilia preparations were incubated with 5alpha-androstenone plus GTP, AC activity was increased fourfold (P<0.01). However, responses of porcine respiratory cilia were not significant statistically, neither were changes in basal levels of AC activities in rat olfactory cilia" |
| Keywords: | "Adenylyl Cyclases/metabolism Androstenes/*metabolism Animals Chromatography Cilia/enzymology/metabolism Female Glycoproteins/isolation & purification/*metabolism Male Microscopy, Electron Molecular Weight Olfactory Mucosa/cytology/*metabolism/ultrastructu;" |
| Notes: | "MedlineKraevskaya, M A Higgins, M J P Wilson, M T Gower, D B eng Research Support, Non-U.S. Gov't England 2003/10/22 J Steroid Biochem Mol Biol. 2003 Aug; 86(2):133-41. doi: 10.1016/s0960-0760(03)00264-4" |
