Immunochemical studies of phospholipids. I. Reactivity of various synthetic cardiolipin derivatives with wassermann antibody

Abstract

The reactivities of various synthetic cardiolipin analogues with syphilitic sera were determined both by the complement fixation and the microflocculation test. 1. 1 Synthetic cardiolipin, the fatty acid residues of which were palmitic residues, showed almost the same activity as beef-heart cardiolipin. 2. 2 A deoxy-derivative of cardiolipin showed slightly lower activity than cardiolipin in the complement fixation test. 3. 3 This deoxy-derivative showed the highest activity of the methylene-inserted derivatives with two phosphodiesters tested, suggesting that the distance between two phosphate groups is important in determination of the serological specificity. 4. 4 A derivative, which had benzyl radicals as hydrophobic groups in place of dipalmitoyl glyceryl groups, did not show any reactivity. These results suggest the importance of a free hydroxy group, two phosphate groups and the diglyceride moieties of the cardiolipin molecule in the reaction of cardiolipin with Wassermann antibody.