Enzyme immunoassay using monoclonal antibodies to study conformational changes of human serum albumin

A method for studying conformational changes induced in the human albumin molecule, either in its purified form or in serum, is described. Plates were coated with albumin or human serum at varying pHs and were reacted with peroxidase-labeled anti-albumin monoclonal antibodies of different specificities. The data showed that albumin molecules were coated in conformations induced as a result of pH changes, allowing us to demonstrate that pH modifications involved the N-terminal portion of the albumin molecule whether in its purified form or in serum. This method should be applicable to the study of conformational modifications in other proteins as well.