Table 2.

The Effect of Alkylation by MTSEA on Pre-Steady State Kinetics

Test condition		τ (ms) at voltage (mV)
MTSEA	Na+	−120	0	+60
	mM
−	100	5.24 ± 0.2	6.8 ± 0.9	2.4 ± 0.4
+	100	2.48 ± 0.4	1.8 ± 0.3	1.2 ± 0.1
−	0	7.7 ± 0.2	7.9 ± 0.7	5.4 ± 0.7
+	0	1.0 ± 0.3	0.9 ± 0.2	0.7 ± 0.1

Time constants (t) measured by single exponential curve fitting to main component of the pre–steady state relaxations in response to voltage steps from a −60-mV holding potential to the indicated voltage. The endogenous charging component was eliminated by subtracting the response to PFA (see text). Data is pooled from five oocytes expressing S460C before (−) and after MTSEA (+) treatment.