Flip-Flop of Phospholipids in DMPC/POPC Mixed Vesicles

Journal of the Korean Chemical Society

article

Min Ki Kim¹  Chul Kim¹ 

[1] Department of Chemistry, Hannam University

关键词: Flip-flop;    DMPC/POPC vesicle;    Fluorescence;   

DOI  :  10.5012/jkcs.2020.64.3.145

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Flip-flop rate constants were measured by dithionite assay of NBD-PE fluorescence in DMPC/POPC vesicles made of various DMPC/POPC ratios. The activation energy, enthalpy, entropy, and free energy were determined based on the transition state theory. We found that the activation energy, enthalpy, and entropy increased as the amount of POPC increased, but the activation free energy was almost constant. These experimental results and other similar studies allow us to propose that the POPC molecules included in DMPC vesicles affect the flip-flop motion of NBD-PE in DMPC/POPC vesicles via increasing the packing order of the ground state of the bilayer of the vesicles. The increase in the packing order in the ground state seems to be a result of the effect of the overall molecular shape of POPC with a monounsaturated tail group, rather than the effect of the longer tail group.

【 授权许可】

Unknown