Conformational analysis of phosphatides: Mapping and minimization of the intramolecular energy

✍ Scribed by Garret Vanderkooi

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 958 KB
• Volume: 11
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(73)90031-5

✦ Synopsis

Empirical intramolecular energy calculations were carried out on molecular fragments related to phosphatides in order to find the preferred conformations. The energy was mapped as a function of several pairs of torsional angles in progressively larger molecular fragments, with energy minimization being carried out at each map point with respect to other significant variables. The energy mapping results were used as starting points for energy minimization on diheptanoyl L-<~-phosphatidic acid-C, which consisted of the named molecule plus a carbon atom attached to one of the phosphate oxygens. It was found that there are 6 pairs of values for 2 of the torsional angles at the 3-way branch point in the glyceryl group which give steritally acceptable conformations; only 4 of these are compatible with lipid bilayer structure in that they can give a parallel arrangement o1 the acyl chains. The several acceptable conformations of the phosphate and acyl ester groups within each of these conformational classes are enumerated. The results obtained may be used as a guide for further experimental and theoretical work on phosphatide structures.