title: Intrinsic coordination for revealing local structural changes in protein folding-unfolding.
abstract: With a deformed object of a rigid rod inside, the local dislocations may be tracked relatively easily with respect to the internal rigid rod. We apply this concept on protein folding-unfolding to track the internal structural changes of an unfolded protein in solution. Proposed here is a protein internal coordination based on the major axis X of an ellipsoidal protein and the stable intrinsic transition dipole moment μ of the protein during unfolding. In this methodology, small-angle X-ray scattering (SAXS) is used to provide the protein global morphologies in the native and unfolded states. Furthermore, time-resolved fluorescence anisotropy (TRFA) provides the relative orientation between X and μ of Trp59 of the model protein cytochrome c. Hence observed in the protein unfolding with denaturants, acid, urea, or GuHCl, is the elongation of the native protein conformation along a reoriented protein major axis; accompanied are the different extents of relocations of the terminal α helices and loop structures of the protein in the corresponding unfolding.
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan. usjeng@nsrrc.org.tw and Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei 106, Taiwan.
authors.forename: Ying-Jen
authors.initials: YJ
authors.lastname: Shiu
authors.affiliation: Center for Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan. atmyh@ntu.edu.tw.
authors.forename: Michitoshi
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan. usjeng@nsrrc.org.tw.
authors.forename: Orion
authors.initials: O
authors.lastname: Shih
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei 106, Taiwan.
authors.forename: Charlene
authors.initials: C
authors.lastname: Su
authors.affiliation: Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
authors.forename: Min-Yeh
authors.initials: MY
authors.lastname: Tsai
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan. usjeng@nsrrc.org.tw.
authors.forename: Yi-Qi
authors.initials: YQ
authors.lastname: Yeh
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan. usjeng@nsrrc.org.tw.
authors.forename: Chun-Jen
authors.initials: CJ
authors.lastname: Su
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan. usjeng@nsrrc.org.tw.
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Huang
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica, P. O. Box 23-166, Taipei 106, Taiwan and Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
authors.forename: Sheng-Hsien
authors.initials: SH
authors.lastname: Lin
authors.affiliation: National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan. usjeng@nsrrc.org.tw and Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: U-Ser
authors.initials: US
authors.lastname: Jeng
mesh_terms: D000818:Animals; D045304:Cytochromes c / Q000737:chemistry*; D006736:Horses; D011487:Protein Conformation; D017510:Protein Folding; D011789:Quantum Theory; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
chemical_list: D045304:Cytochromes c