Analysis of membrane proteins of Mycoplasma capricolum strains by SDS-PAGE and immunoblotting.

Sixteen moroccan and five other Mycoplasma (M.) capricolum strains were characterized by SDS-PAGE as well as by the immunobinding assay and immunoblotting, using antisera against M. capricolum California Kid (CK) and M. mycoides YG. There was a strong reaction of all 21 strains with antiserum against M. capricolum CK and of 18 strains with antiserum against M. mycoides YG in the immunobinding assay, confirming the cross-reactivity between these two species observed earlier. A marked heterogeneity among the M. capricolum strains appeared in SDS-PAGE and in immunoblotting, characterized by different protein patterns and different strengths of identical protein bands. All M. capricolum strains investigated revealed, however, at least three strong protein bands with mol. weights of about 30, 42 and 52 KD reacting in immunoblotting with antiserum against M. capricolum CK but not with antiserum against M. mycoides YG. These proteins may represent antigens suitable for the identification and differentiation of M. capricolum strains.