Table 1

Effect of added Tat protein on incorporation of 75Se by Jurkat T cells

Incubation with 75Se, hrTotal 75Se present/0.6 ml of extract
Control T cells,
Tat-treated T cells,
cpm × 106%cpm × 106%
280.30.51.021.73
501.22.052.854.85

Jurkat T cells were propagated in 6-ml cultures containing RPMI medium 1640 with 10% fetal bovine serum and either maltose-binding protein (42 kDa), 10 μg, (controls) or maltose-binding-Tat fusion protein (52 kDa), 10 μg, (Tat-treated cells) for 24 or 48 hr at 37°C in a CO2 incubator. Then 58.8 × 106 cpm 75SeO32− (ca. 3 nmoles; Los Alamos National Laboratory, NM) were added to each 6-ml culture and incubation was continued for 28 hr (24-hr culture) or 50 hr (48-hr culture). Cells were harvested, washed twice, and suspended in SDS/PAGE sample buffer with mercaptoethanol as described in Materials and Methods. Extracts (0.6 ml) were heated at 100°C for 10 min. 

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