Table 1.

Activities of RtxA and proRtxA on planar lipid membranes

Proteina	Most frequent values of single-pore conductance states with frequency of occurrencea			Most frequent values of lifetimes with frequency of occurrenceb		Overall membrane activity (pA/s)c
	G1 (pS)	G2 (pS)	G3 (pS)	τ1 (s)	τ2 (s)
RtxA	38.4 ± 57.4 (10%)	210.7 ± 66.3 (10%)	419.5 ± 74.3 (80%)	0.24 ± 0.06 (79%)	2.12 ± 0.48 (21%)	8.3
proRtxA	44.8 ± 72.7 (28%)	227.4 ± 99.2 (17%)	433.8 ± 83.3 (55%)	0.23 ± 0.16 (78%)	4.11 ± 0.11 (22%)	1.1

^aSingle-pore conductance states of RtxA and proRtxA (1 nM) were determined in 150 mM KCl, 10 mM Tris-HCl (pH 7.4) and 2 mM CaCl₂ at 25 °C with an applied voltage of 50 mV. The most frequent values of three well-distinguishable single-pore conductance states (G1, G2 and G3) for each protein ± S.D. (half-width at half maximum) are shown. The percentage of the frequency of occurrence for each single-pore conductance state is shown in parentheses

^bFor lifetime determination, the kernel density estimation of dwell times (of ~400 individual pore openings) was fitted with a double-exponential function. The error estimates of lifetimes were obtained by bootstrap analysis. The most frequent values of two well-distinguishable lifetimes (τ1 and τ2) for each protein ± S.D. are shown. The percentage of the frequency of occurrence for each lifetime is given in parentheses

^cThe overall membrane activity of RtxA and proRtxA was determined in asolectin membranes under the same conditions as in (^a) for 5 min and reflects the number of pore-forming molecules in the membrane, conductance (size) and lifetime of single pores, and the frequency of the formation of pores by the proteins