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Cloning, expression and characterisation of a single‐chain antibody fragment to the herbicide paraquat
Author(s) -
Graham Barbara M.,
Porter Andy J. R.,
Harris William J.
Publication year - 1995
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.280630312
Subject(s) - monoclonal antibody , immunoglobulin light chain , chemistry , antibody , paraquat , escherichia coli , microbiology and biotechnology , conjugate , recombinant dna , bovine serum albumin , affinity chromatography , antigen , expression vector , immunoassay , chromatography , biology , biochemistry , enzyme , mathematical analysis , mathematics , gene , immunology , genetics
New cost effective methods for the detection and removal of pesticides from water samples are required to meet modern safety standards. The recent development of techniques to produce antibody fragments in bacteria has provided the opportunity to exploit antibodies as specialised chemicals for affinity detection/removal technologies. The variable heavy and light polypeptide chains of the anti‐paraquat monoclonal antibody PQXB1/2 have been cloned into the single‐chain antibody (ScAb) expression vector pBG1. The construct was expressed in Escherichia coli and 0·4 mg functional antibody produced from 1 dm 3 of induced culture. Characterisation of ScAb by antigen binding profile and competition ELISA showed it to have a sensitivity one order of magnitude below that of the parent monoclonal. ScAb was purified as a monomer or dimer and analysed by HPLC size exclusion chromatography. When immobilised on polystyrene beads the ScAb could remove 85% of a paraquat–bovine serum albumin conjugate from solution in a single step.