Odorant and pheromone binding by aphrodisin, a hamster aphrodisiac protein

Aphrodisin is a soluble glycoprotein of hamster vaginal discharges, which s timulates male copulatory behavior. Natural aphrodisin was purified and its post-translational modifications characterized by MALDI-MS peptide mapping . To evaluate its ability to bind small volatile ligands, the aphrodisiac p rotein was expressed in the yeast Pichia pastoris as two major isoforms dif fering in their glycosylation degree, but close in conformation to the natu ral protein. Dimeric recombinant aphrodisins were equally able to efficient ly bind odors (2-isobutyl-3-methoxypyrazine and methyl thiobutyrate) and a pheromone (dimethyl disulfide), suggesting that they could act as pheromone carriers instead of, or in addition to, direct vomeronasal neuron receptor activators. (C) 2000 Federation of European Biochemical Societies. Publish ed by Elsevier Science B.V. All rights reserved.