Derivatives Containing Different Length Spacers

The antigenicity of liposomes sensitized with haptenated phosphatidylethanolamine (PE) and the reactivity of the liposomes with complement depended on the length of the spacer between hapten and PE. To establish the optimal conditions for the assay, haptenated PE's with various length of spacers are required. In the previous method, hapten-spacer molecule was first synthesized to which PE was conjugated. Therefore, even different hapten molecules and different length of spacer molecules were used, every combination of hapten and spacer has to be synthesized. A new procedure for preparing hapten-spacer-PE was described here. We first prepared conjugates between PE and various length of spacer molecule, the terminal of which is an amino residue. These molecules react well with activated hapten molecules, giving a good yield of hapten-spacer-PE.