HETEROLOGOUS PRODUCTION OF THE P1 PORIN OF NEISSERIA-MENINGITIDIS IN BACILLUS-SUBTILIS - THE EFFECT OF AN N-TERMINAL EXTENSION ON THE PRESENTATION OF NATIVE-LIKE EPITOPES

The major outer membrane protein P1 (class 1) of Neisseria meningitidi s has been produced as inclusion bodies in Bacillus subtilis with the aim to develop a vaccine based on it. The protein produced in high yie ld in B. subtilis contained an N-terminal extension of 11 amino acid r esidues which was found to be necessary for expression in the producti on system. In the present study we asked whether or not the removal of this extension would effect the conformation of this protein in lipos omes as judged by its immunogenic properties. A methionine was enginee red in front of the mature P1 protein to provide a chemical cleavage s ite for CNBr to remove the extension. The CNBr-cleaved protein, comple xed with phospholipids, elicited high titers of antibodies binding to the meningococcal cells similarly to the noncleaved protein. This sugg ests that the BacP1 protein can serve as an effective vaccine componen t irrespective of the presence, or absence, of this N-terminal extensi on.