Title | Self-Assembling Nano-Architectures Created from a Protein Nano-Building Block Using an Intermolecularly Folded Dimeric de Novo Protein. |
Publication Type | Journal Article |
Year of Publication | 2015 |
Authors | Kobayashi, N, Yanase, K, Sato, T, Unzai, S, Hecht, MH, Arai, R |
Journal | J Am Chem Soc |
Volume | 137 |
Issue | 35 |
Pagination | 11285-93 |
Date Published | 2015 Sep 09 |
ISSN | 1520-5126 |
Abstract | <p>The design of novel proteins that self-assemble into supramolecular complexes is an important step in the development of synthetic biology and nanotechnology. Recently, we described the three-dimensional structure of WA20, a de novo protein that forms an intermolecularly folded dimeric 4-helix bundle (PDB code 3VJF ). To harness the unusual intertwined structure of WA20 for the self-assembly of supramolecular nanostructures, we created a protein nanobuilding block (PN-Block), called WA20-foldon, by fusing the dimeric structure of WA20 to the trimeric foldon domain of fibritin from bacteriophage T4. The WA20-foldon fusion protein was expressed in the soluble fraction in Escherichia coli, purified, and shown to form several homooligomeric forms. The stable oligomeric forms were further purified and characterized by a range of biophysical techniques. Size exclusion chromatography, multiangle light scattering, analytical ultracentrifugation, and small-angle X-ray scattering (SAXS) analyses indicate that the small (S form), middle (M form), and large (L form) forms of the WA20-foldon oligomers exist as hexamer (6-mer), dodecamer (12-mer), and octadecamer (18-mer), respectively. These findings suggest that the oligomers in multiples of 6-mer are stably formed by fusing the interdigitated dimer of WA20 with the trimer of foldon domain. Pair-distance distribution functions obtained from the Fourier inversion of the SAXS data suggest that the S and M forms have barrel- and tetrahedron-like shapes, respectively. These results demonstrate that the de novo WA20-foldon is an effective building block for the creation of self-assembling artificial nanoarchitectures.</p> |
DOI | 10.1021/jacs.5b03593 |
Alternate Journal | J Am Chem Soc |
PubMed ID | 26120734 |