FIG. 4.

Immunoblot of samples from the different steps of Pikt purification, performed with antiserum against bovine ubiquitin. Lanes 1 and 2, 50 ng and 25 ng of bovine ubiquitin, respectively; lane 3, 350-fold-concentrated cell-free medium; lanes 4 and 5, fractions 15 and 10, respectively, eluted from the High S cation column and showing killer activity; lane 6, DEAE column flowthrough, showing killer activity; lane 7, High S cation column flowthrough, not showing killer activity; lane 8, fraction 5 eluted from the High S cation column, not showing killer activity; lane M, molecular mass standards (ultra-low-range molecular weight marker; Sigma).