ISSN:
1432-1017
Keywords:
Lipid monolayers
;
domaine structure
;
fluorescence microscopy
;
electrostatics
;
cholesterol
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Physics
Notes:
Abstract The formation of crystalline domains of the phospholipid l-α-dimyristoyl-phosphatidic acid containing 1 mol% cholesterol, was studied as a function of head group charge by fluorescence microscopy with monolayers at the air/water interface. It is shown that the usual dendritic growth occurs at low pH (8), whereas spiral domains are formed at high pH (11), where the head group contains two negative charges. The findings are ascribed to an electrostatically induced chain tilt that, in conjunction with an in-plane dipole moment, causes a ferroelectric state. This allows for domain aggregation and orientation originating in elongated domains that, additionally, are bent because of the chirality of the molecules. The structure is stabilized and further elongated due to the anisotropic edge activity of cholesterol.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00260398
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