Preparation of Carboxythiolactones and Their Active Derivatives

The design of peptidyl immunogens requires that a number of elements be covalently linked to enable the appropriate immune response to occur. Two of these elements are: (a) T-cell sequences which after processing, bind to major histocompatibility complex (MHC) molecules and T-cell receptors and (b) B-cell sequences which embody the constellation of atoms which will ultimately be recognized by the desired antibody. Our concept, designed to effectuate this, involved a single molecule which could conjugate three peptides, potentially in discrete steps, in one pot. Activated carboxythiolactones, hitherto unknown entities, provide such a system: two acyl sites susceptibile to nucleophilic attack at disparate rates and a liberated thiol susceptible to electrophilic alkylation. Such a set of thiolactones and their derivatives have been synthesized from inexpensive starting materials and their reactivities are under investigation. If successful, the system will not only obviate the difficult syntheses of longer linear peptides, but will also allow a rapid structural permutation of the various elements.

activated carboxythiolactones - peptidyl immunogen constructs - oxotetrahydrothiophenecarboxylic acids - oxotetrahydrothianecarboxylic acids