Bile salts within the hydrophobic domains of liposomes and membranes

The classic X-ray diffraction work of Small et al. [5,207,208] pointed out the existence of inverted (reverse) bile salt micelles within mixed bile salt-phospholipid liquid crystalline bilayers. The aggregates were considered to consist of 2-4 molecules (of cholate) with their hydrophilic sides facing inwards bound by hydrogen bonds between the hydroxyl groups, leaving their hydrophobic sides facing outwards to interact with the acyl chains of the phospholipid. At saturation, about 1 molecule of cholate was present for every 2 molecules of lecithin. Appreciably more bile salts 

Several NMR spectroscopic probes have been employed to investigate the interactions of bile salts with model membranes. The results are in general agreement with the deductions above, and suggest additional details  

The functional role of bile salts within model and native membranes has begun to be closely scrutinized in recent years [219-223]. This is not surprising in view of the wide use nf bile salts to extract and reconstitute intrinsic membrane proteins [224] and their use in the formation of vesicles without sonication [225]. There is also scientific and clinical interest in the membrane-damaging properties of bile salts [226,227] and toxicity of bile acids used therapeutically [228], 

Bangham and Lea [219] explored NaCl conductances of black lipid membranes of egg lecithin cephalin (3 1) in the presence of varying concentrations of C and DC 

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Bile salts within the hydrophobic domains of liposomes and membranes... 

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