Chaperone-like effect of monoclonal antibodies on refolding of heat-denatured carboxypeptidase A.

The availability of monoclonal antibodies which bind to a specific antigen at distinct and well-defined sites has led to a better understanding of the effects of highly specific enzyme-antibody interactions on enzyme behaviour. By appropriate selection it has been possible to isolate those antibodies that are non-inhibitory to biological activity of the enzyme and bind at strategic locations on the antigen molecule, resulting in a considerable stabilization effect on the enzyme conformation. Moreover, such monoclonal antibodies proved to have a chaperone activity leading to a considerable refolding effect on the enzyme which was already partially heat denatured. Renaturation of carboxypeptidase A after heat denaturation in the presence of selected monoclonal antibodies, was followed by recovery of its enzymatic activity. The refolding effect of anti-CPA monoclonal antibodies on heat-denatured enzyme depends on the degree of denaturation of the enzyme and on the location of the antigenic site of each antibody. The additivity effect of the pairs of monoclonal antibodies on the refolding process of CPA proved to be dependent on the localization of the antigenic sites of the monoclonal antibodies studied.