Figure 4.

Enzymatic activity that converts de-N-acetyl sialyl 6-sulfo Lewis X to G159-defined cyclic sialyl 6-sulfo Lewis X. The effect of time (A), calcium ion concentration (B), enzyme concentration (C), or pH (D) on the enzymatic activity in ED40515-N homogenates are shown. E indicates subcellular localization of the enzyme; enzymatic activities in a supernatant (Sup.) or precipitate (Ppt.) fraction of ED40515-N homogenates centrifuged at 16,400 × g for 15 min are shown. F indicates the enzymatic activity in the homogenates of representative human leukemic cells and the effect of TPA treatment of the cells. TPA treatment was performed at 20 ng/ml for 3 days for Jurkat cells and 10 ng/ml for 4 days for Namalwa cells.