FIG. 2.

Purification of the cryptococcal protein that stimulates X5A3 by RP-HPLC. The active fractions from an C₁₈ column were applied to a C₄ column and eluted with a gradient of acetonitrile in 0.1% TFA (buffer B). Bioactivity (as measured by the capacity to stimulate X5A3 to produce IL-2 in the presence of APC) was associated with the large peak seen at the 36-min elution time point. The two smaller peaks, eluted immediately after the large peak, also had bioactivity. The results are representative of four column runs.