||Abstract: "Deuterium ((2)H) NMR [Nuclear magnetic resonance] spectroscopy provides detailed information regarding the structural fluctuations of lipid bilayers, including both the equilibrium properties and dynamics. Experimental (2)H NMR measurements for the homologous series of 1, 2-diacyl-sn-glycero-3-phosphocholines with perdeuterated saturated chains (from C12:0 to C18:0) have been performed on randomly oriented, fully hydrated multilamellar samples. For each lipid, the C-D bond order parameters have been calculated from de-Paked (2)H NMR spectra as a function of temperature. The experimental order parameters were analyzed using a mean-torque potential model for the acyl chain segment distributions, and comparison was made with the conventional diamond lattice approach. Statistical mechanical principles were used to relate the measured order parameters to the lipid bilayer structural parameters: the hydrocarbon thickness and the mean interfacial area per lipid."
||P.3184 right column bottom paragraph: "[Investigators] have used the measured 2H NMR order parameters (see Table 1, Table 2, Table 3 and Table 4) to calculate the hydrocarbon thickness DC and the area per lipid 〈A〉 as a function of temperature for the homologous series of 1,2-diacyl-sn-glycero-3-phosphocholines with perdeuterated acyl chains. Both the diamond lattice and mean-torque results are shown in Fig. 8 for comparison to emphasize model-independent features. The conventional method using the diamond lattice result and the whole order profile (Eq. 16) is denoted by DL1. The alternate approach uses the diamond lattice expression (Eq. 1) for the plateau region, together with the assumption of uncorrelated area and segmental projection, and is denoted by DL2. Finally, the mean-torque result, based on the calculation of the area factor q using Eq. 42 for the plateau order parameters is denoted by MT. The results for DL1 and DL2 are compared in Fig. 8, a and b. The first-order MT results are shown in Fig. 8, b and d, and are also listed in Table 5. In addition, Table 5 gives results for DPPE for comparison (Thurmond et al., 1991)." DLPC, DMPC & DSPC are derivatives of Phosphatidylcholine. DPPC is Dipalmitoylphosphatidylcholine. DPPE is a derivative of Phosphatidylethanolamine. See BNID 105806, 105807, 105808,105809