Single-step purification on DEAE-sephacel of recombinant polypeptides produced in Escherichia coli

We describe a method for the purification of recombinant proteins based upon the selective interaction of the choline-binding domain of the pneumococcal murein hydrolase and tertiary amines. Proteins of interest, fused to the binding domain by a peptide linker, containing the cleaving sequence recognized by blood coagulation factor Xa, can either be assayed for biological activities in vitro and in vivo or have the binding moiety removed to yield a totally unmodified form, suitable for clinical and functional studies. The method can also be applied to the production of low molecular mass peptides. The principle of the technique is illustrated with acidic fibroblast growth factor and with a neuropeptide-like fragment of ten amino acids contained within its sequence.