Hybrid spider silk nanostructures
Martin Humenik, Thomas Scheibel
University of Bayreuth, Faculty of Engineering Science, Department of Biomaterials, Germany
Self-assembly of recombinant spider silk proteins into nanofibrills is specifically triggered by low phosphate ions concertation . Therefore, such fibrills represent a nanoscafold highly suitable for incorporation of functional bio-macromolecules.
We prepared DNA-spider silk hybrids, in which self-assembly properties of a recombinant spider silk protein and hybridization properties of DNA were combined in one chemical entity . We demonstrated that corresponding self-assembled silk fibrils exposed nucleic acid strands suitable for specific fibril labeling. Moreover, hybridization of the DNA-silk hybrids into linear or branched constructs allowed controlled hierarchical self-organization of the conjugate fibrils into nano-ribbons and microscopic rafts applying controlled temperature conditions .
Functionality of the nucleic acid moietis was also expoited in DNA directed immobilization of respective spider silk conjugates onto complementary modified surfaces using soft lithography. This strategy enabled initialization of the protein nucleation and fibrils self-assembly on predestined spots and enabled nanofibrils patternig with high- or low-densities across multiple length scales.
In another approach, a recombinant spider silk protein was genetically combined with either the hydrolytic enzyme Esterase 2 or green fluorescent protein GFP. Respective catalytic and light emitting properties of the functional moieties in the fusions were comparable to that of the unmodified precursors in solution as ell as they further maintained their activities upon spider silk self-assembly into fibrils and hydrogels.
Acknowledgement. This work was supported by the Deutsche Forschungsgemeindschaft (SFB 840 TP A8).
1. Humenik, M., Smith, A. M., Arndt, S. & Scheibel, T., (2015) Journal of Structural Biology 4, 571-576
2. Humenik, M. & Scheibel, T., (2014) ACS Nano 8, 1342-1349
3. Humenik, M., Drechsler, M. & Scheibel, T., (2014) Nano Letters 14, 3999-4004