Isolation and purification of the sexual agglutination substance of mating type a cells in Saccharomyces cerevisiae

The substance responsible for the sexual agglutinability was successfully solubilized by a newly established autoclaving method from the surface of mating type $\text{a}$ cells of $\text{Saccharomyces cerevisiae}$ and purified by DEAE cellulose chromatography, gel filtration, affinity chromatography and electrophoresis. The substance was found to consist of at least two different glycoprotein subunits. The molecular weight of the substance was estimated to be about 23,000 daltons by gel filtration. The substance was univalent in its biological activity and specifically masked the sexual agglutinability of the mating type α cells. The substance formed a complementary complex with the agglutination substance from α cells in vitro.