Membrane mediated killing of Saccharomyces cerevisiae by glycoproteins from Torulopsis glabrata

Abstract

Cell free supernatants from cultures of T. glabrata contained glycoprotein toxins that killed sensitive and killer strains of S. cerevisiae with single hit kinetics. Growing S. cerevisiae treated with the toxins showed a leakage of cellular potassium, partial dissipation of the adenosine triphosphate pool, and a coordinate shutdown of macromolecular synthesis. These pool efflux stimulating toxins have been partially purified and at least three toxic glycoproteins have been separated. Pool efflux stimulating toxin activity was stable from pH 3 through 7, though killing was maximal close to pH 4.