| AVS 63rd International Symposium & Exhibition | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI+PB-TuP |
| Session: | Biomaterial Interfaces Poster Session (preceded by Oral Flash Presentations) |
| Presenter: | Richard Rosenberg, Argonne National Laboratory |
| Authors: | R.A. Rosenberg, Argonne National Laboratory D. Mishra, Weizmann Institute of Science, Israel R. Naaman, Weizmann Institute of Science, Israel |
| Correspondent: | Click to Email |
Bacteriorhodopsin (bR) is the integral protein of the purple membrane of Halobacterium salinarum and is the most studied proton pump. It is a chiral system composed of seven parallel, upright-oriented alpha-helices. Recent photoemission and electrochemical studies have shown that it can act as a natural electron spin filter as a result of the chiral-induced spin selectivity effect.[1] Previous structural studies using hard x-ray synchrotron radiation (SR) have shown that such radiation can significantly impact the structural integrity of bR,[2] while earlier work has demonstrated that X-ray-induced, low energy secondary electrons can play a major role in surface chemical reactions of adsorbed biological molecules.[3] In the present study we use SR x-ray absorption and photoelectron spectroscopy (XPS) to characterize the initial state of the adsorbed bR. Time-dependent changes in the core-level XPS spectra are utilized to follow the dynamics of the X-ray/secondary electron induced reaction. The results will be discussed in terms of previous studies of x-ray induced reactions in bR and other biological molecules.
The work performed at the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-06CH11357.
REFERENCES
1 D. Mishra, T. Z. Markus, R. Naaman et al., Proc. Nat. Acad. Sci. 110, 14872 (2013).
2 V. I. Borshchevskiy, E. S. Round, A. N. Popov et al., J. Mol. Biol. 409, 813 (2011).
3 B. Boudaïffa, P. Cloutier, D. Hunting et al., Science 287, 1658 (2000); R. A. Rosenberg, D. Mishra, and R. Naaman, Angew. Chem. Int. Ed. 54, 7295 (2015); R. A. Rosenberg, J. M. Symonds, K. Vijayalakshmi et al., Phys. Chem. Chem. Phys. 16, 15319 (2014).