- Liquid ordered phase
The liquid ordered phase is a
liquid crystal line phase of biological importance. It occurs in many lipid mixtures combiningcholesterol with aphospholipid and/orsphingolipid s e.g.sphingomyelin . This phase has been related tolipid rafts that may exist inplasma membrane s.Definition
The liquid ordered phase can be defined as:
* fluid and lamellar phase
*acyl hydrocarbon chain s are in the all-"trans" state
* rapid lateral diffusion
* 2H-NMR quadrupolar splitting is ca. 50kHz
*Wide angle X-ray scattering pattern centered by broad diffraction peak at 4.2ÅHistory
This was first called the liquid ordered phase by Ipsen et al. (1987). However, it has also been called the LGI subgel phase by Huang et al. (1993) and the β phase by Vist and Davis (1990).
References
*Ipsen, J. H., G. Karlstrom, O. G. Mouritsen, H. Wennerstrom, and M. J. Zuckermann. 1987. Phase equilibria in the phosphatidylcholine-cholesterol system. Biochim. Biophys. Acta. 905:162–172.
*Huang TH, Lee CWB, Dasgupta SK, Blume A, Griffin RG. 1993. "A C-13 and H-2 Nuclear-Magnetic-Resonance Study of Phosphatidylcholine Cholesterol Interactions - Characterization of Liquid-Gel Phases." Biochemistry 32(48):13277-13287
*Vist MR, Davis JH. 1990. "Phase-Equilibria of Cholesterol Dipalmitoylphosphatidylcholine Mixtures - H-2 Nuclear Magnetic-Resonance and Differential Scanning Calorimetry." Biochemistry 29(2):451-464.
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