Table II. Measurement of free nucleotides in HeLa cells after various treatments.
| Free ATP | Total ATP (from Table I) | Free GTP | Total GTP (from Table I) | |
|---|---|---|---|---|
| Glucose− media, 1 h | 4.48 ± 0.27 | 8.22 ± 0.75 | 0.93 ± 0.22 | 2.58 ± 0.23 |
| 2-deoxyglucose + sodium azide, 1 h | <0.1a | 3.27 ± 0.60 | <0.1a | 1.85 ± 0.29 |
| Ribavirin, 2 h | 5.93 ± 1.07 | 8.42 ± 0.43 | 0.30 ± 0.04 | 0.87 ± 0.01 |
Values are expressed as nmoles nucleotide/106 cells. Free nucleotide was separated from the total cellular lysate by filtration as described in the Materials and methods. Values for free ATP and GTP represent the mean ± SD of three independent experiments; the values for total ATP and GTP were taken from separate experiments summarized in Table I.
a
Both the free ATP and GTP from the cells treated with 2-deoxyglucose and sodium azide were essentially undetectable by FPLC, and thus below our lowest standards. The values given for these two measurements therefore indicate the amount of our lowest FPLC standards rather than the exact concentration of nucleotide.