Maximum solubility of cholesterol in phosphatidylcholine and phosphatidylethanolamine bilayers

326Citations
Citations of this article
151Readers
Mendeley users who have this article in their library.

Abstract

In any lipid bilayer membrane, there is an upper limit on the cholesterol concentration that can be accommodated within the bilayer structure; excess cholesterol will precipitate as crystals of pure cholesterol monohydrate. This cholesterol solubility limit is a well-defined quantity. It is a first-order phase boundary in the phospholipid/cholesterol phase diagram. There are many different solubility limits in the literature, but no clear picture has emerged that can unify the disparate results. We have studied the effects that different sample preparation methods can have on the apparent experimental solubility limit. We find that artifactual demixing of cholesterol can occur during conventional sample preparation and that this demixed cholesterol may produce artifactual cholesterol crystals. Therefore, phospholipid/cholesterol suspensions which are prepared by conventional methods may manifest variable, falsely low cholesterol solubility limits. We have developed two novel preparative methods which are specifically designed to prevent demixing during sample preparation. For detection of the cholesterol crystals, X-ray diffraction has proven to be quantitative and highly sensitive. Experiments based on these methods yield reproducible and precise cholesterol solubility limits: 66 mol% for phosphatidylcholine (PC) bilayers and 51 mol% for phosphatidylethanolamine (PE) bilayers. We present evidence that these are true, equilibrium values. In contrast to the dramatic headgroup effect (PC vs. PE), acyl chain variations had no effect on the cholesterol solubility limit in four different PC/cholesterol mixtures. Copyright (C) 1999 Elsevier Science B.V.

Cite

CITATION STYLE

APA

Huang, J., Buboltz, J. T., & Feigenson, G. W. (1999). Maximum solubility of cholesterol in phosphatidylcholine and phosphatidylethanolamine bilayers. Biochimica et Biophysica Acta - Biomembranes, 1417(1), 89–100. https://doi.org/10.1016/S0005-2736(98)00260-0

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free