Table 2.

Tryptophan Fluorescence Lifetime Decay Parameters for SecA and SecA-Signal Peptide Chimeras

protein	α1a	τ1	α2	τ2	α3	τ3	τmb
bsSecA783			0.93	2.7	0.06	6.3	3.2
bsSecA841	0.26	1.2	0.53	4.5	0.21	7.1	5.2
bsSecA783-GS(5)-PhoAss-Cys2-IAEDANS	0.36	1.0	0.48	3.5	0.16	6.9	4.4
bsSecA783-GS(5)-PhoAss-Cys22-IAEDANS	0.38	1.0	0.47	3.6	0.15	7.1	4.5
bsSecA783-GS(2.5)-KRRLamBss-Cys2-IAEDANS	0.24	1.3	0.44	4.1	0.32	6.5	5.1
bsSecA783-GS(2.5)-KRRLamBss-Cys29-IAEDANS	0.29	1.2	0.50	4.2	0.21	6.8	4.9

^aFluorescence decays were fit to a sum of exponentials as described, where α_i represents the fractional subpopulation associated with lifetime, τ_i.

^bThe mean lifetime is calculated using the following equation: ${\tau }_m=\frac{{\displaystyle {\sum }_i{\alpha }_i{\tau }_i^2}}{{\displaystyle {\sum }_i{\alpha }_i{\tau }_i}}$.