Thermodynamics of interdigitated phases of phosphatidylcholine in glycerol

Swamy, M. J. ; Marsh, D. (1995) Thermodynamics of interdigitated phases of phosphatidylcholine in glycerol Biophysical Journal, 69 (4). pp. 1402-1408. ISSN 0006-3495

[img]
Preview
PDF - Publisher Version
607kB

Official URL: http://www.sciencedirect.com/science/article/pii/S...

Related URL: http://dx.doi.org/10.1016/S0006-3495(95)80009-3

Abstract

Comparison of the electron spin resonance spectra of phosphatidylcholines spin-labeled in the sn-2 chain at a position close to the polar region and close to the methyl terminus indicate that symmetrical saturated diacyl phosphatidylcholines with odd and even chain lengths from 13 to 20 C-atoms (and probably also 12 C-atoms) have gel phases in which the chains are interdigitated when dispersed in glycerol. The chain-length dependences of the chain-melting transition enthalpies and entropies are similar for phosphatidylcholines dispersed in glycerol and in water, but the negative end contributions are smaller for phosphatidylcholines dispersed in glycerol than for those dispersed in water: d delta Ht/dCH2 = 1.48 (1.43) kcal.mol-1, d delta St/dCH2 = 3.9 (4.0) cal.mol-1K-1, and delta H o = -12.9 (-15.0) kcal.mol-1, delta S o = -29 (-40) cal.mol-1K-1, respectively, for dispersions in glycerol (water). These differences reflect the interfacial energetics in glycerol and in water, and the different structure of the interdigitated gel phase.

Item Type:Article
Source:Copyright of this article belongs to Biophysical Society.
ID Code:95897
Deposited On:26 Dec 2012 05:41
Last Modified:19 May 2016 08:27

Repository Staff Only: item control page