[Bacterial synthesis of the protein G IgG-binding domain of Streptococcus sp. and prospects of its utilization in immunological practice].

The chemical synthesis of a modified gene fragment that codes IgG-binding domain of protein G of Streptococcus sp. (SPG) was done. Two copies of gene fragmentes SPG were cloned into plasmid vector pET-24(a), for expression of recombinant truncated protein G (rSPG) in the culture of Escherichia coli. IgG-binding capacity and specificity for rSPG was confirmed by model assay such interaction in vitro. Basing on the obtained data we affirm that truncated recombinant protein G is able to bind immunoglobulin G in mammalians and can be used for purification of IgG from sera by affinity chromatography or for synthesis of immunoassay conjugates with broad range specificity.