布鲁氏菌外膜蛋白的研究——Ⅱ.牛、羊、猪三种布鲁氏菌光滑型菌株外膜蛋白SDS-PAGE图谱的比较

Studies on the Outer Membrane Proteins of Brucella Ⅱ.Comparison of SDS-PAGE Profiles of Outer Membrane Proteins Among B.abortus,B. melitensis and B.suis Strains

用两性离子去污剂(Zwittergent 3-14)从牛、羊、猪三种布鲁氏菌不同生物型的光滑型菌株中提取外膜蛋白并进行了SDS-PAGE图谱的比较。发现三种布鲁氏菌光滑型菌株的外膜蛋白在电泳谱型上有极为相似的共同规律:即在大于97.4kD、28～31kD以及小于28kd的三个分子量区段内有着一致的谱带;除此,羊种和猪种布鲁氏菌的外膜蛋白在42.7kD附近有共同的谱带,而牛种布鲁氏菌的外膜蛋白却无。分子量大于97.4kD的一组外膜蛋白在SDS系统中经热解聚后变成一组分子量较小(约为31～42.7kD)的谱带,而该组谱带类型在牛、羊、猪三种布鲁氏菌的光滑型菌株之间存在着极其显著的种的特异性。

Outer membrane proteins were extracted by using a dipolar detergent after enzymolysis of lysozyme from 14 virulent atypical strains of B.abortus and B.melitensis which were isoleted from Inner Mongolia and Qinghai Province in China. The characterization of SDS-PAGE profiles of Omp of the atypical strains was determined and comparison with that of the smooth strains of corresponding typical biovars was performed. It was shown that the pattern of the SDS-PAGE profiles of the Omp displayed a similarity to a great extent in either type strains of Brucella. The bands representing the group 2, group 4 and group 5 Omp were shared in the B.melitenses, no matter what biovar of the strains belonged to, but the group 2 proteins disappeared in the SDS-PAGE profiles of atypical strains just like that in the strains of B.abortus. The obvious variation of the pattern of the SDS-PAGE profiles of group 1(a heat modifiable Omp, the apparent molecular weights were more than 97.4 kD) in the atypical strains of B.melitensis and certain B.abortus were observed, it seemed that the Omp of atypical strains lost some components so that only one broaded band was remained in the region near 97.4 kD but other original bands in this region disappeared. When the group 1 proteins were depolymerized into corresponding monomer( group 3), another two or three bands (31-38 kD) occured in the SDS-PAGE profiles among atypical strains of B.melitensis, but the pattern of SDS-PAGE profiles of the monomer in B.abortus either type was essentially similar. The variation of Omp in atypical strains of Brucella might be the cause that it was very difficult to assign the atypical strains of Brucella by the conventional methods.