Mycobacterium tuberculosis Des protein: an immunodominant target for the humoral response of tuberculous patients.

The phoA gene fusion methodology permitted the identification of a new Mycobacterium tuberculosis exported protein, Des. This protein has significant sequence similarities to plant acyl-acyl carrier protein desaturases, which are enzymes involved in general fatty acid biosynthesis as well as in mycolic acid biosynthesis in mycobacteria. As shown by Western blot and enzyme-linked immunosorbent assay experiments, the Des protein is a major B-cell antigen that was recognized by all the tuberculous M. tuberculosis- and M. bovis-infected human patients tested.