Defined monoclonal antibodies to Escherichia coli beta-galactosidase as a tool for characterisation of recombinant expression products.

Mouse monoclonal antibodies were prepared against beta-galactosidase (EC 3.2.1.23) of Escherichia coli. The binding sites of these monoclonal antibodies within the beta-galactosidase molecule were estimated by immunoblot analyses to various defined peptide regions of beta-galactosidase, encoded by expression plasmids. Monoclonal antibodies were characterised, which either bind to the amino-terminal or to the carboxy-terminal region or to an internal section of beta-galactosidase. These defined monoclonal antibodies were shown to be a useful tool for characterisation of beta-galactosidase fusion proteins expressed in Escherichia coli.