Expression and characterization of Cryptococcus neoformans recombinant App1

We characterized Cryptococcus neoformans recombinant antiphagocytic protein 1 (rApp1) by SDS-PAGE, gel filtration chromatography, circular dichroism, and fluorescence spectroscopy. rApp1 produced by C. neoformans var. grubii contains an odd number of cysteines; therefore, it has the ability to form intermolecular disulfide bridges which can lead to the formation of amyloid fibrils in the absence of β-mercaptoethanol or DTT in vitro. Alternate approaches to over-expression of rApp1 in the Lepidopteran High Five(™) Insect cell line using pIZ/V5-His and in lentivirus were explored and are described. Finally, localization of App1 in vivo was examined in the presence and absence of the capsule.