Construction of a synthetic dragline silk gene multimer and its expression in .

One of the most representative core gene sequence of dragline silk protein partial cDNA monomer (JN857964.2) was selected and multimerized using a "head-to-tail" strategy by compatible but nonregenerable sites at both ends resulting in a concatemer of 16 contiguous monomers. This concatemer was cloned into pET-28a(+) expression vector and transformed into . A 52.6 kDa silk protein was successfully expressed and detected by SDS-PAGE and confirmed by Western blotting. A maximum yield of the silk protein was expressed with 7.06 mM IPTG after 5 h incubation. This is the first report on the construction and overexpression of a dragline silk multimeric gene construct results from our study will provide a reference point for further exploration and development of large-scale production of spider silk protein.