Identification of Leukotoxin and other vaccine candidate proteins in a Mannheimia haemolytica commercial antigen

Tucci, Paula; Estevez, Verónica; Becco, Lorena; Cabrera-Cabrera, Florencia; Grotiuz, Germán; Reolon, Eduardo; Marín, Mónica

Supernatant samples of a M. haemolytica laboratory scale culture were analyzed in order to evaluate the LKT accumulation in the supernatant. To identify LKT specific anti-LKT antibodies were produced. In preliminary evaluation experiments, we confirmed that these antibodies showed the expected reactivity against native and recombinant LKT and a good specific antibody titer. By means of these antibodies we identified LKT as a single defined band of approximately 110 kDa in culture supernatant samples of M. haemolytica (Fig. 1A) . In parallel, the presence of LKT in this protein band was confirmed by MS analysis (MS/MS protein score 408, protein sequence coverage 36%).