Epitopanalyse von Matrix-Metalloproteinase-19-spezifischen monoklonalen Antikörpern

Abstract

By the use of recombinant fragments and synthetic peptides the epitopes of 6 anti-MMP-19 monoclonal antibodies were mapped. With epitope extraction and epitope excision experiments, these peptides were identified as epitopes. The sequences of the peptides were mapped to the propeptide, the catalytic domaine and the hingeregion of MMP-19.The results indicated, that 4 antibodies (CK7/4, 7/5, 8/2, and 8/3) recognize two different MMP-19 fragments, which represent different domaines, and which are separated by each other. These are the propeptide, and the catalytic domaine together with the hingeregion. Each of these antibodies recognize the propeptide, and except CK7/4, the hingeregion, too. CK7/5 recognize with low affinity the zink-binding region of the catalytic domaine. The epitope fragment of the propeptide could be mapped down to a fragment, 43 aminoacids in length (aa 30-72 of MMP-19). The epitope of the hingeregion could be identified as the aminoacids 298-325 of MMP-19.The antibody CK8/6 reacts only with this 28 aminoacid peptide of the hingeregion, but not with the propeptide.The antibody CK8/4 recognize only the propeptide with a very high affinity. In this case, the epitope fragment could be mapped down to an peptide, 29 aminoacids in length (aa 38-66 of MMP-19).Non of the antibodies recognize the Hemopexin-like domaine of MMP-19.The sequences of the mapped epitopes have a very low homology to other MMPs, therefore these monoclonal antibodies are very specific for MMP-19.