| Title: | Structure of segments of a G protein-coupled receptor: CD and NMR analysis of the Saccharomyces cerevisiae tridecapeptide pheromone receptor |
| Author(s): | Arshava B; Liu SF; Jiang H; Breslav M; Becker JM; Naider F; |
| Address: | "College of Staten Island of the City University of New York 10314, USA" |
| DOI: | 10.1002/(SICI)1097-0282(199811)46:6<343::AID-BIP1>3.0.CO;2-L |
| ISSN/ISBN: | 0006-3525 (Print) 0006-3525 (Linking) |
| Abstract: | "Peptides representing both loop and the sixth transmembrane regions of the alpha-factor receptor of Saccharomyces cerevisiae were synthesized by solid-phase procedures and purified to near homogeneity. CD, nmr, and modeling analysis indicated that in aqueous media the first extracellular loop peptide E1(107-125), the third intracellular loop peptide I3(231-243), and the carboxyl terminus peptide I4(350-372) were mostly disordered. In contrast, the second extracellular loop peptide E2(191-206) assumed a well-defined structure in aqueous medium and the sixth transmembrane domain peptide receptor M6(252-269, C252A) was highly helical in trifluoroethanol/water (4:1), exhibiting a kink at Pro258. A synthetic peptide containing a sequence similar to that of the sixth transmembrane domain of a constitutively active alpha-factor receptor M6(252-269, C252A, P258L) in which Leu replaces Pro258 exhibited significantly different biophysical properties than the wild-type sequence. In particular, this peptide had very low solubility and gave CD resembling that of a beta-sheet structure in hexafluoroacetone/water (1:1) whereas the wild-type peptide was partially helical under identical conditions. These results would be consistent with the hypothesis that the constitutive activity of the mutant receptor is linked to a conformational change in the sixth transmembrane domain. The study of the receptor segments also indicate that peptides corresponding to loops of the alpha-factor receptor do not appear to assume turn structures" |
| Keywords: | "Amino Acid Sequence Chemoreceptor Cells/*chemistry Circular Dichroism GTP-Binding Proteins/*chemistry Magnetic Resonance Spectroscopy Models, Molecular Molecular Sequence Data Peptides/*chemical synthesis Receptors, Mating Factor Receptors, Peptide/chemis;" |
| Notes: | "MedlineArshava, B Liu, S F Jiang, H Breslav, M Becker, J M Naider, F eng GM 22086/GM/NIGMS NIH HHS/ GM 22087/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 1998/11/03 Biopolymers. 1998 Nov; 46(6):343-57. doi: 10.1002/(SICI)1097-0282(199811)46:6<343::AID-BIP1>3.0.CO; 2-L" |
