Antibody Engineering

ImmunoSolv routinely generates full DNA sequence data for any monoclonal antibody or antigen-binding antibody fragments that we generate, and are also able to sequence customer supplied hybridoma cell lines.  Due to the highly conserved nature of antibodies both within and between species at the protein and DNA levels, we are able to offer to range of protein engineering services.  The most popular of these is the conversion from whole antibody to antibody fragment and vice versa.  Whole antibodies are generated, typically from a hybridoma cell line, and fragments (scFv) from antibody display libraries.  Hybridomas are cloned by first isotyping the antibody and cloning out the antibody variable region (antigen-binding) genes by 5’-RACE PCR using mRNA purified from cultures cells.  Where necessary, N-terminal sequencing of purified protein is also carried out.  In this way, we are able to determine the precise 5’-sequences of the heavy and light chain variable region genes so avoiding the introduction of amino acid changes during PCR. 

In order to generate antibody fragments, the V-region genes are extended to introduce appropriate restriction sites, and assembled into an appropriate expression vector depending on the fragment format required.  These fragments (scFv, scAb, Fab) can be readily expressed in E. coli for further characterization and development.  ImmunoSolv has a panel of expression vectors available to introduce a variety of popular tags to the protein, e.g. for purification or detection purposes, and are able to engineer additional changes to the antibody, such as optimizing codon usage for different expression systems, increasing protein stability, improving binding affinity.  In a similar way, antibody fragments can be readily engineered into whole IgG formats by cloning the V-genes onto genes encoding human or murine constant domains for expression in mammalian cells.

We are also happy to discuss other customer requirements not specifically mentioned here.