Chemical Structure of Mating Pheromone Peptides, αsk1and αsk3Pheromones, Produced by Mating Type α Cells ofSaccharomyces kluyveri

Three peptides, αsk1, αsk2 and αsk3 pherornones, have been isolated as α-mating pheromones of Saccharomyces kluyveri, the primary structure of the main active component, αsk2 pheromone, having already been determined. The unknown N-terminus of αsk1 pheromone was elucidated to be l, 2, 3, 4-tetrahydro-β-carbolme-3-carboxylic acid (β-CAR) by mass and NMR spectrometric analyses. Synthetic β-CAR-His-Trp-OH was identical with N-terminal tripeptide fragment obtained from αsk1 pheromone, and the primary structure of αsk1 pheromone was determined as β-CAR-His-Trp-Leu-Ser-Phe-Ser-Lys-Gly-Glu-Pro-Met(O)-Tyr-OH. The amino acid sequence of αsk3 pheromone was determined as H-Trp-His-Trp-Leu-Ser-Phe-Ser-Lys-Gly-Glu-Pro-Met-OH by comparing the enzymatic fragments with those of αsk2 pheromone.