Self-assembled bionanoparticles based on the Sulfolobus tengchongensis spindle-shaped virus 1 (STSV1) coat protein as a prospective bioscaffold for nanotechnological applications
Biomolecule-nanoparticle hybrid bioconjugates based on bioscaffolds such as protein cages and virus capsules have been widely studied. Highly stable and durable biotemplates are a vital pillar in constructing bio-inorganic functional hybrid composites. Here, we introduce a highly heat-resistant coat protein (CP) of Sulfolobus tengchongensis spindle-shaped virus 1 (STSV1) isolated from the hyperthermophilic archaeon as a prospective biological matrix. Our experiments showed that STSV1 CP was successfully cloned and solubly expressed in the Escherichia coli Rosetta-(DE3) host strain. Protein expression was verified by SDS-PAGE and western blot analysis of the reference C-terminally six-histidine (His6) tagged STSV1 CP (HT-CP). Thermal stability experiments showed that the STSV1 coat protein remained fairly stable at 80 °C. The proteins can be purified facilely by heat treatment followed by size exclusion chromatography (SEC). Transmission electron microscopy (TEM) analysis of the purified STSV1 CP protein aggregates demonstrated that the protein could self-assemble into rotavirus-like nanostructures devoid of genetic materials under our experimental conditions. Similar results were obtained for the HT-CP purified by heat treatment followed by Ni-NTA and SEC, indicating that moderately engineered STSV1 CP can retain its self-assembly property. In addition, the STSV1 CP has a high binding affinity for TiO2 nanoparticles. This illustrates that the STSV1 CP can be used as a bioscaffold in nanobiotechnological applications.
KeywordsBioscaffold STSV1 CP Protein expression and purification Protein nanoscale self-assembly Affinity binding
We are grateful to Prof George F. Gao’s research group from IM, CAS for generous support. The authors wish to thank Ms. Jingnan Liang from IM, CAS for TEM analyses. We also thank Prof. Paul Chu, guest professor of Institute of Microbiology, Chinese Academy of Sciences, for critical reading of the manuscript and providing constructive comments and suggestions. This work was supported by Grants from the National Basic Research Program of China (973 Program, Grant Nos. 2011CB504703 and 2010CB530102) and the National Natural Science Foundation of China (NSFC, Grant Nos. 81321063 and 31270211).
- Destito G, Schneemann A, Manchester M (2009) Biomedical nanotechnology using virus-based nanoparticles. Curr Top Microbiol 327:95–122Google Scholar