Isolation of the major outer-membrane protein of Actinobacillus pleuropneumoniae and Haemophilus parasuis.

A polyclonal antibody against the 35 kDa major outer-membrane protein of Pasteurella multocida cross-reacted with the 40 kDa major outer-membrane protein of Actinobacillus pleuropneumoniae and the 42 kDa major outer-membrane protein of Haemophilus parasuis. The N-terminal amino-acid sequences of these proteins revealed a strong homology with the putative 35 kDa porin protein of Pasteurella multocida (66.7 and 76.2%, respectively). Significant homologies were also evident between the 40 kDa and the 42 kDa protein (76.2%), and with non-specific porins of gram-negative bacteria.