[2P-84*] Barium ion responsive reversible assembly of protein supramolecule TIP60
Protein nanoparticle is attractive molecular materials owing to the structural homogeneity and genetical/chemical modifiable properties. We have previously constructed a hollow protein nanoparticle TIP60 composed of 60-mer designed fusion proteins of pentamer protein LSm and dimer protein Myo-X coil1. TIP60 can encapsulate various molecules through its porous surface. Molecular size of cargo is restricted by the pore size, and it is difficult to encapsulate macromolecules such as protein or nucleic acid. In this study, we have attempted to confer metal-ion dependent reversible assembly mechanism to TIP60.
We first introduced mutation to the LSm subunit interface to obtain the mutant does not form 60-mer structure and found a mutant K67E that forms dimeric structure. We found that K67E forms 60-mer structure in the presence of typical metal ions such as Ca, Sr and Ba and it rapidly decompose after addition of excess EDTA. The reconstituted structure was confirmed by Native-PAGE, size-exclusion chromatography, transmission electron microscope and small angle X-ray scattering.
1. N. Kawakami et al., Angew. Chem. Int. Ed., 2018
We first introduced mutation to the LSm subunit interface to obtain the mutant does not form 60-mer structure and found a mutant K67E that forms dimeric structure. We found that K67E forms 60-mer structure in the presence of typical metal ions such as Ca, Sr and Ba and it rapidly decompose after addition of excess EDTA. The reconstituted structure was confirmed by Native-PAGE, size-exclusion chromatography, transmission electron microscope and small angle X-ray scattering.
1. N. Kawakami et al., Angew. Chem. Int. Ed., 2018