Conformation of the Acyl Chains in Diacylphospholipid Gels by IR Spectroscopy

Autor: Wen-Hong Yan, Robert G. Snyder, and Herbert L. Strauss
Rok vydání: 2000
Předmět:
Zdroj: The Journal of Physical Chemistry B. 104:4229-4238
ISSN: 1520-5207
1520-6106
DOI: 10.1021/jp993944n
Popis: An IR study of the conformational disorder in the part of the hydrocarbon chain nearest the ester group in gel-phase lipid bilayers is presented. The infrared method for determining the conformation of the CH2−CH2 bond attached to the ester group is discussed and applied to a number of representative gel-phase 1,2-diacylphosphatidylcholine fully hydrated dispersions, including symmetric and mixed-chain PCs in their gel and subgel phases. The effect on chain conformation of the headgroups PC, PE, and PA- was explored. Only two conformations of the alkyl chains were found: a planar (all-trans) chain and a nonplanar chain that is all-trans except for the CH2−CH2 bond nearest the ester group. Concentrations of the two conformers were also determined. The overall concentration of the planar form always exceeds 50% but varies significantly depending on the lipid involved. In two cases, the concentration of the planar conformer was estimated for both the SN1 and SN2 chains.
Databáze: OpenAIRE