Title: | Nuclear-magnetic-resonance studies on the conformations of tridecapeptide alpha-mating factor from yeast Saccharomyces cerevisiae and analog peptides in aqueous solution. Conformation-activity relationship |
Author(s): | Higashijima T; Masui Y; Chino N; Sakakibara S; Kita H; Miyazawa T; |
DOI: | 10.1111/j.1432-1033.1984.tb08081.x |
ISSN/ISBN: | 0014-2956 (Print) 0014-2956 (Linking) |
Abstract: | "The conformation of tridecapeptide alpha-mating factor from yeast Saccharomyces cerevisiae in aqueous solution was analyzed, in comparison with those of active analog and inactive analog peptides. 270-MHz 1H-NMR spectra of these peptides were observed and the spectral patterns of main-chain N-H proton resonances were classified into three groups. alpha-mating factor and Trp1-bearing active peptides belong to the group A1, active des-Trp1-peptides belong to the group A2 while the peptides of group B are inactive. The main-chain N-H proton resonances of the groups A1 and A2 and side-chain N-H proton resonances were all assigned to individual residues. The 13C-NMR analysis of alpha-mating factor indicates that the Lys7-Pro8 and Gln10-Pro11 peptide bonds exclusively take the trans form. From the temperature and pH dependences of chemical shifts and Gd(III)-induced relaxation enhancements of amide proton resonances, alpha-mating factor is found to take partly a folded conformation in aqueous solution, with an alpha-helical form in the N-terminal domain and two beta-turn forms in the central and C-terminal domain. The pH dependence of fluorescence intensity indicates that, in this folded conformation, the C-terminal carboxylate group lies close to the N-terminal domain. The presence of the folded form in the N-terminal domain and the beta-turn form in the central domain correlates with the biological activity of alpha-mating factor and analog peptides. However, the folded conformation of alpha-mating factor is in equilibrium with predominantly unordered form, as found from the circular dichroism and NMR analyses. The N-H proton and C-alpha proton resonances of free alpha-mating factor as assigned in the present study allow the transferred nuclear Overhauser enhancement (NOE) analysis of the membrane-bound conformation that is more directly related with the activity" |
Keywords: | "Amides/isolation & purification Chemical Phenomena Chemistry Circular Dichroism Hydrogen-Ion Concentration Magnetic Resonance Spectroscopy Mating Factor *Peptides Protein Conformation Protons Saccharomyces cerevisiae/*metabolism Spectrometry, Fluorescence;" |
Notes: | "MedlineHigashijima, T Masui, Y Chino, N Sakakibara, S Kita, H Miyazawa, T eng Research Support, Non-U.S. Gov't England 1984/04/02 Eur J Biochem. 1984 Apr 2; 140(1):163-71. doi: 10.1111/j.1432-1033.1984.tb08081.x" |