Isolation of a monoclonal antibody to the TrpE protein and its use for the purification of recombinant fusion proteins.

The trpE (or anthranilate synthetase) gene product has been used extensively as a fusion protein for the expression of a myriad of biologically active proteins. A trpE construct can be produced in high yield, is relatively resistant to proteolysis, and separates from the bulk of E. coli proteins because of its insolubility. We have isolated and characterized a monoclonal antibody against the TrpE protein for use as a detection and immunoaffinity reagent. The MAb, TRP 7.4, is highly specific for the TrpE protein and has a relative affinity of 1.0 ng. The antibody can also be used to detect TrpE constructs on Western blots. In addition, TRP 7.4 has been used to purify a TrpE-IL-6 fusion protein. These studies show the utility of this MAb as a tool for both research and protein purification.