PARTIAL CHARACTERIZATION AND IDENTIFICATION OF A TRANSFERRIN-LIKE MOLECULE OF PATHOGENIC YEAST CRYPTOCOCCUS NEOFORMANS

Abstract

We have partially characterized, purified, and N-terminal amino acid sequenced a protein of approximately 80kDa from Cryptococcus neoformans. Of the 15N-terminal amino acids sequenced, 12 are identical to those found in ovotransferrin. Polyclonal antisera raised against ovotransferrin crossreacted with the 80kDa protein. In addition, incorporation of ⁵⁵Fe indicated the presence of iron binding by the 80 kDa protein. Because Cryptococcus neoformans does not possess an iron-scavenging ligand, siderophore, we suggest that an alternative transferrin-like molecule (the 80kDa protein) may play a role in iron uptake by this organism.