Project B4

Hydrogen bonding network in channelrhodopsins analyzed by site-directed labeling and EPR spectroscopy

Principal Investigators: Prof. Dr. Robert Bittl (FU), Dr. Ramona Schlesinger (FU)

Conformational changes and alterations in the hydrogen bonding network of channelrhodopsin will be investigated by site-directed labeling and electron paramagnetic resonance (EPR) spectroscopy. Constructs will be generated where the native cysteine residues are reduced to a minimum and new cysteines for spin labeling are introduced to detect changes in polarity and hydrogen bonding by virtue of the sensitivity of the spin-label EPR parameters. Moreover the project aims at identifying and analyzing protein conformational changes essential for understanding protonation dynamics using pulsed electron-electron double resonance on doubly spin-labeled constructs.

Publications 2013 - 2017

Harris N.J., Reading E., Ataka K., Grzegorzewski L., Charalambous K., Liu X., Schlesinger R., Heberle J., and Booth P.J. (2017). Structure formation during translocon-unassisted co-translational membrane protein folding. Scientific Reports 7: 8021.

Krause, N., Engelhard, C., Heberle, J., Schlesinger, R., and Bittl, R. (2013). Structural differences between the closed and open states of channelrhodopsin-2 as observed by EPR spectroscopy. FEBS Letters 587, 3309-3313.

Lorenz-Fonfria, V.A., Resler, T., Krause, N., Nack, M., Gossing, M., von Mollard, G.F., Bamann, C., Bamberg, E., Schlesinger, R., and Heberle, J. (2013). Transient protonation changes in channelrhodopsin-2 and their relevance to channel gating. Proceedings of the National Academy of Sciences of the United States of America 110, E1273-E1281.

Lórenz-Fonfría, V.A., Muders, V., Schlesinger, R., and Heberle, J. (2014). Changes in the hydrogen-bonding strength of internal water molecules and cysteine residues in the conductive state of channelrhodopsin-1. Journal of Chemical Physics 141, 22D507.

Lórenz-Fonfría, V.A., Bamann, C., Resler, T., Schlesinger, R., Bamberg, E., and Heberle, J. (2015). Temporal evolution of helix hydration in a light-gated ion channel correlates with ion conductance. Proceedings of the National Academy of Sciences of the United States of America 112, E5796-E5804.

Lórenz-Fonfría, V.A., Schultz, B.-J., Resler, T., Schlesinger, R., Bamann, C., Bamberg, E., and Heberle, J. (2015). Pre-Gating Conformational Changes in the ChETA Variant of Channelrhodopsin-2 Monitored by Nanosecond IR Spectroscopy. Journal of the American Chemical Society 137, 1850-1861.

Muders, V., Kerruth, S., Lorenz-Fonfria, V.A., Bamann, C., Heberle, J., and Schlesinger, R. (2014). Resonance Raman and FTIR spectroscopic characterization of the closed and open states of channelrhodopsin-1. FEBS Letters 588, 2301-2306.

Resler, T., Schultz, B.-J., Lorenz-Fonfria, V.A., Schlesinger, R., and Heberle, J. (2015). Kinetic and Vibrational Isotope Effects of Proton Transfer Reactions in Channelrhodopsin-2. Biophysical Journal 109, 287-297.

Schnedermann, C., Muders, V., Ehrenberg, D., Schlesinger, R., Kukura, P., and Heberle, J. (2016). Vibronic Dynamics of the Ultrafast all-trans to 13-cis Photoisomerization of Retinal in Channelrhodopsin-1. Journal of the American Chemical Society 138, 4757-4762.

Sezer, M., Kielb, P., Kuhlmann, U., Mohrmann, H., Schulz, C., Heinrich, D., Schlesinger, R., Heberle, J., and Weidinger, I.M. (2015). Surface Enhanced Resonance Raman Spectroscopy Reveals Potential Induced Redox and Conformational Changes of Cytochrome c Oxidase on Electrodes. Journal of Physical Chemistry B 119, 9586-9591.

Sezer, M., Woelke, A.-L., Knapp, E.W., Schlesinger, R., Mroginski, M.A., Weidinger, I.M. (2017). Redox induced protonation of heme propionates in cytochrome c oxidase: Insights from surface enhanced resonance Raman spectroscopy and QM/MM calculations. Biochimica et Biophysica Acta (BBA) - Bioenergetics 1858, 103-108.

Stensitzki, T., Muders, V., Schlesinger, R., Heberle, J., and Heyne, K. (2015). The primary photoreaction of channelrhodopsin-1: Wavelength dependent photoreactions induced by ground-state heterogeneity. Frontiers in Molecular Biosciences 2, 41.

Stensitzki, T., Yang, Y., Muders, V., Schlesinger, R., Heberle, J., and Heyne, K. (2016). Femtosecond infrared spectroscopy of channelrhodopsin-1 chromophore isomerization. Structural Dynamics 3, 043208.

Volz, P., Krause, N., Balke, J., Schneider, C., Walter, M., Schneider, F., Schlesinger, R., and Alexiev, U. (2016). Light and pH-induced changes in structure and accessibility of transmembrane helix B and its immediate environment in Channelrhodopsin-2. The Journal of Biological Chemistry 291, 17382-17393.