摘　　要：牛支原体（M｜boris）可以引起犊牛肺炎、关节炎、乳腺炎、角膜结膜炎等疾病，是一种牛的重要呼吸道病原体。目前M．bovis粘附宿主细胞的机制还不明确。研究表明，M.boris表面存在的多种蛋白与致病菌在宿主体内的侵袭力与传播能力有关。我们通过分离表达多个M．bovis基因，最终获得了一个表达纤溶酶原结合蛋白的新基因，并命名为P18。该基因表达大小约为67ku的重组蛋白。通过westemblot鉴定，重组表达的P18蛋白可以被M．bovis抗体识别。进一步的试验表明，P18蛋白还具有纤溶酶原结合活性，从而推测该基因表达的蛋白可能是Mbovis的一个粘附相关因子。 Mycoplasma bovis is the causative agent of M. bovis-associated disease （MbAD）. While the mechanisms by which M. bovis adherent host cells is remain unclear, our recent study provided that M. boris express variable surface lipop proteins （Vsps） is facilitated it invasion and dissemination in the infected host and speculated that there are other adhesion-related factors in existence of M. bovis. We cloned and expressed a novel gene of M. bovis, designate P18, which express a profibrinolysin binding protein according to the domain sequence analysis binding test. The P18 gene express a 67 ku recombinant protein. The recombinant P18 protein were detected by SDS-PAGE and confirmed by western blot with positive serum. There fore, we conjectured that P18 protein is one of M. bovis adhesion-related factors.