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Kichitaro Nakajima, Hirotsugu Ogi, Kanta Adachi, Kentaro Noi, Masahiko Hirao, Hisashi Yagi & Yuji Goto "Nucleus factory on cavitation bubble for amyloid β fibril", Scientific Reports, volume 6, Article number: 22015, Springer Nature, 2016

Hirotsugu Ogi, Masahiko Fukukshima, Hiroki Hamada, Kentaro Noi, Masahiko Hirao, Hisashi Yagi & Yuji Goto "Ultrafast propagation of β-amyloid fibrils in oligomeric cloud", Scientific Reports, volume 4, Article number: 6960, Springer Nature, 2014

Jin Chen, Hisashi Yagi, Yuji Furutani, Takashi Nakamura, Asumi Inaguma, Hao Guo, Yan Kong & Yuji Goto "Self-assembly of the chaperonin GroEL nanocage induced at submicellar detergent", Scientific Reports, volume 4, Article number: 5614, Springer Nature, 2014, Protein nanoassemblies possess unique advantage in biomedical applications such as drug delivery, biocatalysis and vaccine development. Despite recent accomplishment in atomic structure data, the underlying molecular mechanism of protein self-assembly remains elusive, where considerable heterogeneity is often involved. Here we use E. coli chaperonin GroEL, a tetradecameric protein with a molecular weight of 805 kDa, to probe its transformation from cage-like oligomers to protein nanofibers. We show that sodium dodecyl sulfate (SDS), a widely-used protein denaturant, at submicellar concentration binds to and causes partial distortion of GroEL apical domain. Subsequently, the GroEL apical domain with altered secondary structural content converts the GroEL oligomers into modular structural units which are observed to self-assemble into cylindrical nanofibers under an agitated incubation in a physiological buffer. Interestingly, through targeted mutagenesis where two cysteine residues are introduced at the entry site of GroEL cage, we found that the formation of GroEL nanoassembly could be modulated depending on the redox condition of incubation. Without the need of chemical engineering, tunable GroEL nanofibers built by controlled-assembly are among the largest nanoscale bioassembly with broad applications.

Jin Chen, Hisashi Yagi, Yuji Furutani, Takashi Nakamura, Asumi Inaguma, Hao Guo, Yan Kong & Yuji Goto "Self-assembly of the chaperonin GroEL nanocage induced at submicellar detergent", Scientific Reports, volume 4, Article number: 5614, Springer Nature, 2014, Protein nanoassemblies possess unique advantage in biomedical applications such as drug delivery, biocatalysis and vaccine development. Despite recent accomplishment in atomic structure data, the underlying molecular mechanism of protein self-assembly remains elusive, where considerable heterogeneity is often involved. Here we use E. coli chaperonin GroEL, a tetradecameric protein with a molecular weight of 805 kDa, to probe its transformation from cage-like oligomers to protein nanofibers. We show that sodium dodecyl sulfate (SDS), a widely-used protein denaturant, at submicellar concentration binds to and causes partial distortion of GroEL apical domain. Subsequently, the GroEL apical domain with altered secondary structural content converts the GroEL oligomers into modular structural units which are observed to self-assemble into cylindrical nanofibers under an agitated incubation in a physiological buffer. Interestingly, through targeted mutagenesis where two cysteine residues are introduced at the entry site of GroEL cage, we found that the formation of GroEL nanoassembly could be modulated depending on the redox condition of incubation. Without the need of chemical engineering, tunable GroEL nanofibers built by controlled-assembly are among the largest nanoscale bioassembly with broad applications.