TABLE 2.

Kinetic and thermodynamic parameters for the translocation of the phospholipid derivatives in all lipid bilayers tested

Probe	Lipid bilayer composition	ΔHo‡ (kJ/mol)	TΔSo‡ (kJ/mol)*	ΔGo‡ (kJ/mol)*†	kf* (s−1)
NBD-DMPE	POPC	119 ± 5	21 ± 1	99 ± 1	(1.1 ± 0.4) × 10−4
NBD-lysoMPE		131 ± 2	30 ± 1	101 ± 1	(4.9 ± 0.8) × 10−5
NBD-DMPE	POPC/Chol (1:1)	143 ± 14	38 ± 4	106 ± 4	(1 ± 1) × 10−5
NBD-lysoMPE		133 ± 5	23 ± 1	110 ± 1	(1.7 ± 0.5) × 10−6
NBD-DMPE	SpM/Chol (6:4)	153 ± 11	39 ± 3	113 ± 1§	(4 ± 2) × 10−7§
NBD-lysoMPE			141 ± 12	23 ± 4	118 ± 1§	(7 ± 3) × 10−8§

^*At 35°C.

^†The standard deviations were calculated from the standard deviations of the rate constant at 35°C.

^§Those parameters are extrapolations from the best fit to the temperature range accessed experimentally (45–65°C). The standard deviations shown are the average of the standard deviations of the rate constants at the temperatures studied.