Antibody as an immunological probe for studying the refolding of bovine serum albumin. II. Evidence for the independent refolding of the domains of the molecule.

Antiserum to bovine serum albumin were used as a probe for native structure to study the process of refolding of denatured bovine serum albumin. Different antigenically active fragments that represent domains and subdomains of the molecule were isolated. Restricted populations of antibody to albumin were obtained by fractionating antisera to the native intact molecule on immunoadsorbents bearing these fragments. The restricted antibody populations were then used to probe the surface of the molecule during the refolding process. Some regions of the molecule refolded more rapidly than other regions. Isolated domains of albumin also refolded to native antigenic structure demonstrating that the entire polypeptide chain was not necessary for reformation of native structure. However, there does seem to be some interdomain influence on the rate of refolding of a particular domain within the intact protein.