Acid phosphatases of Sporothrix schenckii

Department of Biochemistry, University of Kansas Medical Center, Kansas City, Kansas 66103, USA ABSTRACT Summary: Sporothrix schenckii cells were grown on a medium containing yeast extract, neopeptone and glucose at 20°C to obtain a mixture of mycelia and conidia, and at 35°C to obtain yeast-like cells. The organism was maintained in the mycelial form, and its transformation to yeast at the higher temperature proceeded via conidia and ‘intermediate cells’ that then gave rise to yeast by a blastic mechanism. Cell-free extracts were analysed by PAGE at pH 8.0 and acid phosphatases (EC 3.1.3.2 ) were revealed by a sensitive detection reagent at pH 5.0. Mycelial, conidial and yeast extracts all had some acid phosphatase activity (M-I, C-I and Y-I) at the origin, although the proportion was highest for the yeast extracts. All of the bands that penetrated the gels had different electrophoretic mobilities. Mycelial and conidial extracts each had one other isoenzyme (M-II and C-II), while the yeast extracts had a total of five electrophoretically distinct acid phosphatases. Isoenzyme Y-II was further resolved into five closely related bands (Y-II a to Y-Il e ), the relative intensities of which varied with the phosphate nutrition of the yeast cells and the history of the extracts. The acid phosphatase isoenzymes were inhibited to various extents by sodium fluoride, L(+)-tartrate and phosphate, and showed interactions with citrate as opposed to acetate as the background buffer at pH 5.0.