Table 3.
Idealized and segmented current records from the same patches were fitted by Scheme V as shown in Fig. 8C
| Scheme V | |||
|---|---|---|---|
| Control | 300 nm Zn2+ | Zn2+/Control | |
| k1 (s−1) | 1100 | 900 | 0.82 |
| k2 (s−1) | 2700 | 3200 | 1.19 |
| k3 (s−1) | 3800 | 4200 | 1.11 |
| k4 (s−1) | 1900 | 2600 | 1.37 |
| k5 (s−1) | 6300 | 6500 | 1.03 |
| k6 (s−1) | 1200 | 1200 | 1.00 |
| k7 (m−1 s−1) | 1.4e+9 | 1.4e+9 | — |
| k8 (s−1) | 47 | 12 | 0.26 |
| k9 (s−1) | 630 | 150 | 0.24 |
| kH1 (s−1) | 300 | 610 | 2.03 |
| kH2 (s−1) | 750 | 2200 | 2.93 |
| kH3 (s−1) | 900 | 820 | 0.91 |
| kH4 (s−1) | 5800 | 6700 | 1.16 |
| kH5 (s−1) | 5500 | 5000 | 0.91 |
| kH6 (s−1) | 1100 | 920 | 0.84 |
| logL/event | 5.13 | 5.02 | — |
Records from all 7 patches were pooled and fitted simultaneously. The proton concentration was 62 nm (pH 7.3). All loops were constrained to obey microscopic reversibility; proton association rate was fixed to 1.4 × 109m−1 s−1 (Banke et al. 2005); all other rate constants were free parameters during fitting. The ratio of rate constants determined in 300 nm Zn2+ to those determined for control conditions (10 mm tricine, no added Zn2+) is given in the far right column. Rates in bold show more than a 3-fold change in the presence of Zn2+. Rate constants are given to two significant digits.