This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The study of protein structural dynamics has been an important subject in biology owing to its significance in understanding the structure-function relationship of the proteins. Despite intense investigations using various spectroscopic techniques complete characterization of intermediate structures involved in a conformational change still remains elusive due to the limitation in structural sensitivity of the spectroscopic techniques. To achieve that goal we propose to investigate the conformational change of zinc-substituted cytochrome c (Zn Cyt-c) and wild type cytochrome c (Fe Cyt-c) by using time-resolved wide-angle X-ray scattering (TR-WAXS). Cyt-c is a small single-domain heme protein with 104 amino acids and has been considered a useful model system for studying structural dynamics. In case of zinc-substituted cytochrome c the Zn atom in its heme group is usually covalently coordinated with His 18 residue and Met 80 residue simultaneously. (Figure 1) (1) However if Zn Cyt-c is photoexcited the residue coordinated with zinc is dissociated accompanying the change of the protein structure and the Zn oxidation state. Previously a study using time-resolved fluorescence spectroscopy suggested the structural reorganization of Zn Cyt-c in solution after photoinduced ligand dissociation. (2) The results indicate that the dissociation of axial ligands from Zn(II) atom by laser irradiation induces the reorganization of the protein from its native folded state. In the same study two kinetic components were identified: a fast component of about 120 ps time constant and a slow one of 7 ns time constant. These constants are related with the existence of penta- and tetra-coordinated Zn Cyt-c intermediate structures. (2) In this proposed experiment we plan to investigate the conformational dynamics of Zn Cyt-c using TR-WAXS under pH7 and phosphate buffer condition. This study will allow us to directly follow the protein conformational changes associated with the ligand dissociation. In addition by comparatively measuring the wild type Fe Cyt-c in the same time range as for Zn Cyt-c we aim to find out the relationship between the type of a metal ion in the heme group and the conformational dynamics.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR007707-19
Application #
8363689
Study Section
Special Emphasis Panel (ZRG1-BCMB-P (40))
Project Start
2011-08-01
Project End
2012-07-31
Budget Start
2011-08-01
Budget End
2012-07-31
Support Year
19
Fiscal Year
2011
Total Cost
$36,495
Indirect Cost
Name
University of Chicago
Department
Miscellaneous
Type
Schools of Medicine
DUNS #
005421136
City
Chicago
State
IL
Country
United States
Zip Code
60637
Kazantsev, Roman V; Dannenhoffer, Adam J; Weingarten, Adam S et al. (2017) Crystal-Phase Transitions and Photocatalysis in Supramolecular Scaffolds. J Am Chem Soc 139:6120-6127
Fournier, Bertrand; Sokolow, Jesse; Coppens, Philip (2016) Analysis of multicrystal pump-probe data sets. II. Scaling of ratio data sets. Acta Crystallogr A Found Adv 72:250-60
Cho, Hyun Sun; Schotte, Friedrich; Dashdorj, Naranbaatar et al. (2016) Picosecond Photobiology: Watching a Signaling Protein Function in Real Time via Time-Resolved Small- and Wide-Angle X-ray Scattering. J Am Chem Soc 138:8815-23
Pande, Kanupriya; Hutchison, Christopher D M; Groenhof, Gerrit et al. (2016) Femtosecond structural dynamics drives the trans/cis isomerization in photoactive yellow protein. Science 352:725-9
Weingarten, Adam S; Kazantsev, Roman V; Palmer, Liam C et al. (2015) Supramolecular Packing Controls H? Photocatalysis in Chromophore Amphiphile Hydrogels. J Am Chem Soc 137:15241-6
Yang, Xiaojing; Stojkovi?, Emina A; Ozarowski, Wesley B et al. (2015) Light Signaling Mechanism of Two Tandem Bacteriophytochromes. Structure 23:1179-89
Mariette, Céline; Guérin, Laurent; Rabiller, Philippe et al. (2015) The creation of modulated monoclinic aperiodic composites in n-alkane/urea compounds. Z Kristallogr Cryst Mater 230:5-11
Pfoh, Roland; Pai, Emil F; Saridakis, Vivian (2015) Nicotinamide mononucleotide adenylyltransferase displays alternate binding modes for nicotinamide nucleotides. Acta Crystallogr D Biol Crystallogr 71:2032-9
Sampath, Sujatha; Yarger, Jeffery L (2015) Structural hysteresis in dragline spider silks induced by supercontraction: An x-ray fiber micro-diffraction study. RSC Adv 5:1462-1473
Coppens, Philip; Fournier, Bertrand (2015) New methods in time-resolved Laue pump-probe crystallography at synchrotron sources. J Synchrotron Radiat 22:280-7

Showing the most recent 10 out of 110 publications