Creatine kinase-inhibiting monoclonal antibodies: preparation and characterization of porcine MM isoenzyme-specific antibodies.

Five monoclonal antibodies (CKM-B07, F12, D08, H09 and G01) against porcine creatine kinase (CK; EC 2.7.3.2) MM isoenzyme, which inhibit the enzymatic activity, were prepared. The hybridomas which produced monoclonal antibodies were screened by direct measurement of the inhibitory activity of their culture supernatant. Only two of them, however, were found to be measurable by an enzyme-linked immunosorbent assay with porcine CK-MM as an antigen. CKM-G01 inhibited 100% porcine CK-MM activity, while the others, 73-87%. On the other hand, only CKM-H09 inhibited porcine CK-BB activity (15%). CKM-F12 and D08 inhibited more than 50% CK-MB activity, whereas they did not inhibit CK-BB activity. The monoclonal antibodies were also tested for bovine, rabbit and human CK-MM. All the antibodies inhibited bovine and human CK-MM activity as well. In particular, CKM-G01 was found to exhibit more than 98% inhibition of all CK-MM activity tested, indicating that a common or very similar epitope which affects the activity is present on these enzymes. Admixing of CKM-B07 with other antibodies effected synergisms in inhibition, not only to porcine CK-MM activity but also to human CK-MM activity. A mixture of CK-B07 and G01 inhibited 100% human CK-MM activity, suggesting applicability of these monoclonal antibodies to clinical laboratory diagnosis.