Investigation of the redox-dependent modulation of structure and dynamics in human cytochrome c

Journal Article · Fri Jan 22 00:00:00 EST 2016 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2015.12.079· OSTI ID:22594191

Imai, Mizue ^[1]; Saio, Tomohide ^[1]; Kumeta, Hiroyuki ^[2]; Uchida, Takeshi ^[1]; Inagaki, Fuyuhiko ^[2]; Ishimori, Koichiro ^[1]

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1. Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810 (Japan)
2. Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021 (Japan)

Redox-dependent changes in the structure and dynamics of human cytochrome c (Cyt c) were investigated by solution NMR. We found significant structural changes in several regions, including residues 23–28 (loop 3), which were further corroborated by chemical shift differences between the reduced and oxidized states of Cyt c. These differences are essential for discriminating redox states in Cyt c by cytochrome c oxidase (CcO) during electron transfer reactions. Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments identified that the region around His33 undergoes conformational exchanges on the μs-ms timescale, indicating significant redox-dependent structural changes. Because His33 is not part of the interaction site for CcO, our data suggest that the dynamic properties of the region, which is far from the interaction site for CcO, contribute to conformational changes during electron transfer to CcO. - Highlights: • Solution structure and dynamics analysis for human Cyt c by NMR. • Structural changes responsible for the discrimination of the redox state in Cyt c. • Conformational exchange in the region outside of the interaction site for CcO. • Less flexibility and rigid structure of the interaction site on Cyt c for CcO.

• OSTI ID: 22594191
• Journal Information: Biochemical and Biophysical Research Communications, Vol. 469, Issue 4; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CHEMICAL SHIFT
CONFORMATIONAL CHANGES
ELECTRON TRANSFER
GILLS
MODULATION
NUCLEAR MAGNETIC RESONANCE
OXIDASES
REACTION KINETICS
RELAXATION
TRANSFER REACTIONS