Abstract: Heparin could inhibited the adhesion of Trueperella pyogenes to host cells in a dose-dependent manner. To understand the heparin binding proteins from T. pyogenes and their adhesion characteristics, the proteins were extracted from the lysate of T. pyogenes by heparin aga-rose gel, and were identified by protein mass spectrometry and Western blotting. The reactivity of the extracted proteins with the serum from a goat naturally infected with T. pyogenes was detected by Western blotting. The recombinant proteins were prepared. The heparin binding activity of recombinant proteins and the inhibitory effect of heparin or the antiserum on the binding of recombinant proteins to heparin were analyzed. The cell adhesion activity of the recombinant proteins and the inhibitory effect of the antiserum on the adhesion of T. pyogenes to host cells were analyzed. The results showed that multiple substrate binding proteins of ATP binding cassette transporters including iron-binding protein (IBP) were extracted. The IgG antibody against IBP was detected in the serum of naturally infected goat with T. pyogenes, which indicated that IBP was expressed in the process of T. pyogenes infection. The result of SDS-PAGE showed that rIBP could bind heparin agarose gel, and the physiological concentration of NaCl could partially dissociate the rIBP bound to heparin agarose gel. The result of Western blotting showed that heparin could inhibit rIBP binding heparin agarose gel in a dose-dependent manner, indicating that rIBP specifically binds heparin. Western blot showed that rIBP could adhere to MDBK cells. Western blotting results showed that anti-rIBP serum could not inhibit the binding of rIBP to heparin, but the results of viable bacteria counting showed that anti-rIBP serum could inhibit the adhesion of T. pyogenes to MDBK cells. The result of this study laid a foundation for further understanding heparin binding proteins of T. pyogenes and their role in the adhesion of T. pyogenes to host cells.

Key words: Trueperella pyogenes, heparin binding proteins, iron-binding protein, adhesion, heparin