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.
Levin
Y
Y
Department of Chemistry, College of Staten Island, City University of New York 10301.
Khare
R K
RK
Abel
G
G
Hill
D
D
Eriotou-Bargiota
E
E
Becker
J M
JM
Naider
F
F
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