| Title: | Position 13 analogs of the tridecapeptide mating pheromone from Saccharomyces cerevisiae: design of an iodinatable ligand for receptor binding |
| Author(s): | Liu S; Henry LK; Lee BK; Wang SH; Arshava B; Becker JM; Naider F; |
| Address: | "Department of Chemistry, The College of Staten Island and The Graduate School of The City University of New York, 10314, USA" |
| DOI: | 10.1034/j.1399-3011.2000.00730.x |
| ISSN/ISBN: | 1397-002X (Print) 1397-002X (Linking) |
| Abstract: | "Analogs of the alpha-factor tridecapeptide mating pheromone (WHWLQLKPGQPMY) from Saccharomyces cerevisiae in which Tyr13 was replaced with Phe, p-F-Phe, m-F-Phe, p-NO2-Phe, p-NH2-Phe or Ser were synthesized and purified to >99% homogeneity. These analogs were bioassayed using a growth arrest assay and a gene induction assay and evaluated for their ability to compete with binding of tritiated alpha-factor to its receptor Ste2p. The results showed that the phenolic OH of Tyr13 is not required for either biological activity or receptor recognition. Analogs containing fluorine, amino, nitro or a hydrogen in place of OH had 80-120% of the biological activity of the parent pheromone in the gene induction assay and had receptor affinities from nearly equal to 6-fold lower than that of alpha-factor. In contrast, substitution of Ser or Ala at position 13 resulted in a >100-fold decrease in receptor affinity suggesting that the aromatic ring is involved in binding to the receptor. The lack of a strict requirement for Tyr13 allowed the design of several multiple replacement analogs in which Phe or p-F-Phe were substituted at position 13 and Tyr was placed in other positions of the peptide. These analogs could then be iodinated and used in the development of a highly sensitive receptor-binding assay. One potential receptor ligand [Tyr(125I)1,Nle12, Phe13] alpha-factor exhibited saturable binding with a KD of 81 nM and was competed by alpha-factor for binding in a whole-cell assay. Thus a new family of radioactive ligands for the alpha-factor receptor has been revealed. These ligands should be extremely useful in defining active site residues during mutagenesis and cross-linking studies" |
| Keywords: | "Binding, Competitive Cell Division/drug effects Cell Membrane/chemistry Chromatography, High Pressure Liquid Dose-Response Relationship, Drug Fungal Proteins/*chemistry/metabolism Iodine Radioisotopes/chemistry Ligands Mating Factor Models, Chemical Pepti;" |
| Notes: | "MedlineLiu, S Henry, L K Lee, B K Wang, S H Arshava, B Becker, J M Naider, F eng GM 22086/GM/NIGMS NIH HHS/ GM 22087/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, P.H.S. Denmark 2000/08/05 J Pept Res. 2000 Jul; 56(1):24-34. doi: 10.1034/j.1399-3011.2000.00730.x" |
