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. Author manuscript; available in PMC: 2015 Aug 1.
Published in final edited form as: J Biomol NMR. 2014 Aug;59(4):263–277. doi: 10.1007/s10858-014-9845-z

Figure 8.

Figure 8

Cryoprotectants partially immobile lipids. (a–d) 13C-1H dipolar couplings of DMPC membranes in the absence and presence of cryoprotectants. The data were obtained at 280 K under 3.3 kHz MAS. From the left to right, the columns correspond to (a) Control DMPC membrane, (b) Glycerol-bound membrane, (c) PEG-400 bound membrane, and (d) DMSO-bound membrane. Solid lines are best-fit simulations with empirical T2 decay values indicated. Glycerol-bound DMPC exhibits similar order parameters as the control membrane while PEG-400 and DMSO give rise to larger dipolar couplings, indicating lipid immobilization. (e) 31P MAS spectra of the four membranes at 273 K, showing larger sideband intensities for the cryoprotected samples than the control sample. (f) C-H order parameters of the four samples at 280 K for all resolved signals. Dashed lines guide the eye for the rigid limit (SCH = 1.0) and SCH = 0.50. For the control DMPC sample and the glycerol-bound DMPC sample, most sites exhibit SCH values lower than 0.5, while the PEG- and DMSO-bound DMPC samples have SCH values between 0.5 and 1.0 except for the chain end and the headgroup C.