Conformational analysis of 6-cis- and 6-trans-leukotriene B4-calcium complexes.

Abstract

A computational description of the conformation of a pair of 2 isomeric molecules (6-cis- and 6-trans-leukotriene B4) forming a complex with 1 Ca ion is presented. The theoretical prediction of the membrane-water interface conformation and of the bulk lipid phase conformation of the 2 different isomeric complexes is in excellent agreement with experimental data on the leukotriene-mediated Ca ionophoresis in liposomes. The 2 isomers lead to vastly different conformations in the presence of Ca2+, and the most probable conformation of the permeant species shows a globular conformation able to cross a lipid membrane.