The 3069bp fragment of apxIA was amplified from the reference strain 259 of Actinobacillus pleuropneumoniae by PCR and cloned into the pMAL-c2X vector.The recombinant expression vector was transformed into Escherichia coli TB1 and induced by IPTG for expression.The target protein was purified by Amylose Column.The results showed that the recombinant expression plasmid apxIA-c2X was successfully constructed.The SDS-PAGE and Western-blot analysis showed that the apxIA gene could be expressed efficiently in E....