Histidine2 of the alpha-factor of Saccharomyces cerevisiae is not essential for binding to its receptor or for biological activity.
Seven His2 analogs of the Saccharomyces cerevisiae [Nle12]alpha-factor, WXWLQLKPGQP(Nle)Y, where X = beta-D-thienylalanine, beta-L-thienylalanine, 1-D-methylhistidine, 1-L-methylhistidine, 3-D-methylhistidine, 3-L-methylhistidine, and beta-3-L-pyridylalanine, were synthesized and purified to homogeneity. Assays were carried out on binding to the alpha-factor receptor and of biological activity determined by either growth arrest or morphological changes in target cells. In the L-isomer, replacement of the imidazole of histidine by thiophene or 3-pyridyl groups or derivatization of either nitrogen of the imidazole ring by methylation resulted in a 2-100-fold decrease in bioactivity. D-Isomers of the beta-thienylalanyl-, 1-methylhistidinyl-, or 3-methylhistidinyl-alpha-factors did not possess measurable bioactivity with the exception of comparatively low activity of the 3-D-methylhistidinyl and 1-D-methylhistidinyl-alpha-factors in the morphogenesis assay. In contrast, both active and inactive analogs demonstrated binding affinities 10-20-fold less than that of [Nle12]alpha-factor. These results indicate that the histidine residue of alpha-factor is not required for binding to the receptor or for biological activity and that bioactivity and binding can be dissociated through the use of pheromone analogs.
Department of Chemistry, College of Staten Island, City University of New York 10301.
Y
Y
Levin
R K
RK
Khare
G
G
Abel
D
D
Hill
E
E
Eriotou-Bargiota
J M
JM
Becker
F
F
Naider
D000595:Amino Acid Sequence; D001667:Binding, Competitive; D002851:Chromatography, High Pressure Liquid; D006639:Histidine / Q000031:analogs & derivatives / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D000072235:Mating Factor; D008762:Methylhistidines / Q000737:chemistry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000378:metabolism*; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000187:drug effects / Q000254:growth & development; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013329:Structure-Activity Relationship; D014157:Transcription Factors
D008762:Methylhistidines; D010455:Peptides; D011956:Receptors, Cell Surface; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D014157:Transcription Factors; D006639:Histidine; D000072235:Mating Factor