The single crystal structure of octadecyl-2-methyl-glycero-phosphocholine monohydrate. A multilamellar structure with interdigitating head groups and hydrocarbon chains
✍ Scribed by I. Pascher; S. Sundell; H. Eibl; K. Harlos
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 544 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0009-3084
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✦ Synopsis
The molecular conformation, packing properties and polar group interactions of octadecyl-2-methyl-phosphatidylcholine have been determined by X-ray single crystal analysis. The lipid molecules pack in stacked bilayers with interdigitating head groups and interdigitating and tilting hydrocarbon chains. Adjacent bilayer have alternating chain tilt. The unit cell (orthorhombic, P212t2~) spans two bilayers and has the dimensions a = 8.38, b = 8.82, c = 47.68 A.
The phosphocholine dipols of adjacent bilayers are oriented layer parallel and pack side by side in a common head group matrix. This results in a spacious packing cross-section (S = 74 A 2) per molecule which is four times larger than the cross-section (X = 19 A s) of the hydrocarbon chain. Despite the rather unusual packing features the molecular conformation is entirely identical with the preferred conformation observed for equivalent parts in the corresponding double chain lipids.