Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Construction of an S-layer protein exhibiting modified self-assembling properties and enhanced metal binding capacities

Pollmann, K.; Matys, S.

The functional S-layer protein gene slfB of the uranium mining waste pile isolate Bacillus sphaericus JG-A12 was cloned as a PCR-product into the expression vector pET Lic/Ek 30 and heterologous expressed in E.
coli Bl21(DE3). The addition of His-tags to the N- and C-termini enabled the purification of the recombinant protein by Ni chelating chromatography. The Ni-binding capacity of the His-tagged recombinant S-layer protein was compared with that of the wild-type S-layer. The ICP-MS analyses demonstrate a significantly enhanced Ni-binding capability of the recombinant protein. In addition, the self-assembling properties of the purified modified S-layer proteins were studied by light microscopy and SEM. Whereas the wild-type S-layer proteins re-assembled into regular cylindric structures, the His-tagged S-layer proteins reassembled into regular sheets that formed globular agglomerating structures. The nanoporous structure of the protein meshwork together with its enhanced Ni-binding capacity makes the recombinant S-layer attractive as a novel self-assembling biological template for the fabrication of metal nanoclusters and construction of nanomaterials that are of technical interest.

Publ.-Id: 9044