An antigen assay based on a monoclonal antibody directed against the light chain of
tissue-type plasminogen activator (t-PA) was developed to quantify seven recombinant
(r) t-PA deletion mutant proteins. These recombinant proteins were then employed to
map different epitopes on t-PA which interact with a panel of twenty-three monoclonal
anti-t-PA antibodies. Twenty were directed against domains on the heavy chain, two
against the “finger” domain, three against the “epidermal growth factor-like” domain,
five against the kringle 1 domain, and ten against the kringle 2 domain. Only three
monoclonal anti-t-PA antibodies interact with the light chain. The finding that the
epitopes of each of the monoclonals could be determined with the deletion mutant proteins
supports the hypothesis of autonomous folding of structural domains and emphasizes
the validity of the use of the recombinant t-PA-deletion mutant proteins for structure-function
studies.
Keywords
Recombinant tissue-type plasminogen activator - Monoclonal antibodies - Epitopes -
Domain structure
