Novel antigenic determinants from peptidorhamnomannans of Sporothrix schenckii

Antisera were raised in rabbits against acetone-dried yeast-likeand mycelium forms of Sporothrix schenckii. These antisera weretested for immunoprecipitation of peptidorhamnomannans isolatedfrom both cell types. Both antisera reacted strongly with S.schenckiipeptidorhamnomannans, but the reactions were weak with ß-eliminatedpeptidopolysaccharides. These antisera did not recognize theSaccharomyces cerevisiae mannoprotein, and reacted poorly withCeratocystis (Ophiostoma) stenoceras cell wall glycopeptides.Since ß-eliminated glycopeptides were poorly reactive,we investigated the activity of O-glycosidically linked oligosaccharideswhich were liberated from the peptidorhamnomannans by mild alkalinehydrolysis, using a hapten inhibition test. The rates of inhibitionshowed that the immunodominant epitopes in O-linked tetra- andpentasaccharides had the following novel structures: