TABLE 2.

Surface shear viscosities η_s and intermonolayer friction coefficients b obtained for the various coarse-grained lipid models of this study

Lipid	ηs (× 10−11 Pa m−1 s) Driven*	Equilibrium	b (×106 Pa m−1 s) Driven	Equilibrium
A44 (DPPC)	1.2	1.0	2.4	3.0
A53	1.0	1.0	3.9	4.1
A62	1.0	1.0	7.1	7.3
A55	1.8	1.8	2.8	2.7
A66	2.9	4.2	3.3	2.5
A77	4.8	7.5	3.2	2.4
A5′5		2.1	2.8
DPPC				∼1†
DMPC				0.7‡
DMPC	500§	17,¶ 500§		30–3000¶
DOPC		17¶		45–450¶
SOPC	300‖	300‖	100,** 450††	500–104‡‡

The values in the two columns marked “Driven” are obtained from membranes flowing under external forces, while those in the columns marked “Equilibrium” are extracted from thermal motions. Simulation results from atomic models are presented in rows 8 and 9, and experimental data in the bottom three rows.

^*The simulation data under perpendicular shear flow have been extrapolated to zero shear rate.

^†Derived from the relaxation of thermal undulations; see Lindahl and Edholm (43) and this work.

^‡Based on the relative diffusion of monolayers; see Wohlert and Edholm (37).

^§Obtained from Brownian and driven motion of latex spheres bound to a vesicle; see Dimova et al. (9).

^¶From the diffusion of lipids in supported bilayers; see Merkel et al. (23).

^‖Obtained from Brownian and driven motion of latex spheres bound to a vesicle; see Velikov et al. (7) and Dimova et al. (8).

^**Derived by pulling a tether from a vesicle; see Evans and Yeung (19).

^††Tether pulling experiments; see Raphael and Waugh (21).

^‡‡Analyzing the thermal undulations of a vesicle by two theories; see Pott and Méléard (25).