%0 Journal Article %A Morrison, Christine J. %A Hurst, Steven F. %A Bragg, Sandra L. %A Kuykendall, Randall J. %A Diaz, Humberto %A McLaughlin, David W. %A Reiss, Errol %T Purification and characterization of the extracellular aspartyl proteinase of Candida albicans: removal of extraneous proteins and cell wall mannoprotein and evidence for lack of glycosylation %D 1993 %J Microbiology, %V 139 %N 6 %P 1177-1186 %@ 1465-2080 %R https://doi.org/10.1099/00221287-139-6-1177 %I Microbiology Society, %X Aspartyl proteinase (AP) is an extracellular enzyme of Candida albicans implicated as a pathogenic factor. Previous reports on the purification and characterization of AP suggested that a single DEAE-Sephadex chromatographic step was sufficient for the removal of extraneous proteins and that the final product was glycosylated. We purified AP using a chromatographic series consisting of DEAE-Sephadex A25, Sephadex G75 and rechromatography on DEAE-Sephadex A25. Use of DEAE-Sephadex alone did not remove extraneous proteins and removed little contaminating mannoprotein (MP). The addition of a Sephadex G75 column to the purification scheme removed the majority of contaminating MP and proteins. The final DEAE-Sephadex A25 chromatographic step resulted in (a) removal of detectable extraneous proteins, (b) removal of immunologically detectable MP by dot blot and Western blot enzyme immunoassay,(c) loss of periodic acid-silver stain positivity, and (d) a high AP yield (1295 U I−1) and specific activity (1749 U mg−1). We conclude that a single DEAE-Sephadex A25 purification step is insufficient to remove extraneous proteins and MP, which could interfere with the production of AP-specific antibodies and the dissection of moieties responsible for immune reactivity. Reports of periodic acid-Schiff or anthrone positivity of AP preparations may reflect the presence of extraneous MP, which can be removed by the chromatographic series we describe. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-139-6-1177