title: Nanoscale probing of electron-regulated structural transitions in silk proteins by near-field IR imaging and nano-spectroscopy.
abstract: Silk protein fibres produced by silkworms and spiders are renowned for their unparalleled mechanical strength and extensibility arising from their high-β-sheet crystal contents as natural materials. Investigation of β-sheet-oriented conformational transitions in silk proteins at the nanoscale remains a challenge using conventional imaging techniques given their limitations in chemical sensitivity or limited spatial resolution. Here, we report on electron-regulated nanoscale polymorphic transitions in silk proteins revealed by near-field infrared imaging and nano-spectroscopy at resolutions approaching the molecular level. The ability to locally probe nanoscale protein structural transitions combined with nanometre-precision electron-beam lithography offers us the capability to finely control the structure of silk proteins in two and three dimensions. Our work paves the way for unlocking essential nanoscopic protein structures and critical conditions for electron-induced conformational transitions, offering new rules to design protein-based nanoarchitectures.
authors.affiliation: State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Qin
authors.affiliation: Department of Mechanical Engineering, the University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Jianjuan
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: Stephanie Gilbert
authors.identifier: 0000-0002-5041-8670
authors.initials: SG
authors.lastname: Corder
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Qian
authors.affiliation: State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Zhitao
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Mechanical Engineering, the University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Woonsoo
authors.initials: W
authors.lastname: Lee
authors.affiliation: State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Keyin
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, the University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.|School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Huashan Hospital of Fudan University, Wulumuqi Zhong Road 12, Shanghai, 200040, China.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Department of Neurosurgery, Huashan Hospital of Fudan University, Wulumuqi Zhong Road 12, Shanghai, 200040, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Mao
authors.affiliation: Nano-FTIR, Advanced Light Source Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Hans A
authors.initials: HA
authors.lastname: Bechtel
authors.affiliation: Nano-FTIR, Advanced Light Source Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Michael C
authors.identifier: 0000-0002-6611-070X
authors.initials: MC
authors.lastname: Martin
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Xia
authors.affiliation: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Benedetto
authors.initials: B
authors.lastname: Marelli
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, USA.|Department of Chemical Engineering, Tufts University, Medford, Massachusetts 02155, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.affiliation: Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, USA.|Department of Physics, Tufts University, Medford, Massachusetts 02155, USA.
authors.forename: Fiorenzo G
authors.initials: FG
authors.lastname: Omenetto
authors.affiliation: Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA.
authors.forename: Mengkun
authors.initials: M
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.|Department of Mechanical Engineering, the University of Texas at Austin, Austin, Texas 78712, USA.|School of Physical Science and Technology, ShanghaiTech University, Shanghai 200031, China.
authors.forename: Tiger H
authors.initials: TH
authors.lastname: Tao
mesh_terms: D000818:Animals; D012831:Bombyx / Q000378:metabolism; D005349:Fibroins / Q000737:chemistry* / Q000648:ultrastructure*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008968:Molecular Conformation; D047011:Silk / Q000737:chemistry* / Q000648:ultrastructure*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013112:Spiders / Q000378:metabolism
chemical_list: D047011:Silk; D005349:Fibroins