ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The self-diffusion coefficients (D) and 1H spin–spin relaxation times (T2) of poly(γ-oleyl L-glutamate)(POLLG) with long oleyl side chains and poly(γ-n-octadecyl L-glutamate)(POLG) with n-alkyl side chains have been measured by the pulse field-gradient spin-echo 1H nuclear magnetic resonance (NMR) method and the Carr–Purcell/Meiboom–Gill (CPMG) 1H NMR method, respectively, over a wide range of temperatures from 30 to 80 °C, in order to elucidate the dynamic behavior of polypeptides in the thermotropic liquid crystalline state, which take the α-helical conformation. From these experiments, it was found that the diffusion coefficients of POLLG and POLG chains in the thermotropic liquid crystalline state at 60 °C are 9.97×10−7 and 3.53×10−7 cm2/s, respectively, and the former diffuses faster than the latter. The diffusion coefficients of POLG in the directions parallel (D(parallel)) and perpendicular (D⊥) to the α-helical chain axis were determined over a wide range of temperatures, and the D(parallel) value was found to be much larger than the D⊥ value. Further, from the 1H T2 experiments, it was suggested that the mobility of the side chains relates closely to the diffusion process. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1312278
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