TABLE 1.

Parameters obtained from the NLLS fits for 16-PC, CSL, and DPPTC spin labels in pure DPPC and DPPC/Chol vesicles at 50°C

Sample	R⊥ (× 108 s−1)	R‖ (× 109 s−1)	S0	S2	ωexc (× 106 s−1)
DPPC/16-PC*	2.5	7.5	0.16	−0.28	2.6
DPPC/Chol/16-PC*	4.4	9.0	0.41	−0.30	—§
SM/16-PC*	2.1	1.7	0.16	−0.17	1.8
SM/Chol/16-PC*	6.8	3.1	0.43	−0.23	—§
DPPC/CSL†	0.36	0.80	0.75	0.03	4.5
DPPC/Chol/CSL†	0.14	0.21	0.90	0.01	0.2
DPPC/DPPTC‡	0.11	0.49	0.75	—§	4.8
DPPC/Chol/DPPTC‡	0.76	4.7	0.53	−0.19	—§

^*Magnetic parameters for 16-PC: A_xx = A_yy = 5.0 G; A_zz = 33.0 G; g_xx = 2.0089; g_yy = 2.0058; g_zz = 2.0021 (Ge et al., 1999); diffusion tilt: ϕ = 31° (Patyal et al., 1997).

^†Magnetic parameters for CSL: A_xx = 4.9; A_yy = 5.5; A_zz = 33.1; g_xx = 2.0087; g_yy = 2.0057; g_zz = 2.0021 (Barnes and Freed, 1998).

^‡Magnetic parameters for DPPTC: A_xx = 5.6; A_yy = 5.6; A_zz = 34.6; g_xx = 2.0082; g_yy = 2.0053; g_zz = 2.0015 (Ge and Freed, 1998).

^§Very small values, so kept fixed at 0.

Estimated errors: R_⊥ (5%), R_‖ (10%), S₀ (1%), S₂ (1%), ω_exc (10%).