Studying the photocycle of halo rhodopsin, a chloride pump, with FTIR as well as FT visible and FT Raman. Renewal request of a previous 3 year award, now back to BBCA as an amended proposal.
Specific aims are to resolve the photocycle of hR. Examine whether or not the Schiff base frequency is halide dependent and whether or not bands from the arginine side groups are also halide dependent. Then, try to identify which args are those showing up in the IR difference spectrum. One last goal is to obtain IR difference spectra in response to, with and without halide salts in solution, using an ATR cell and flowing the ions. A new faster (5 microsecond) FT-IR spectrometer has just been installed. This will provide about three orders of magnitude better resolution.
| Hutson, M S; Shilov, S V; Krebs, R et al. (2001) Halide dependence of the halorhodopsin photocycle as measured by time-resolved infrared spectra. Biophys J 80:1452-65 |
| Hutson, M S; Alexiev, U; Shilov, S V et al. (2000) Evidence for a perturbation of arginine-82 in the bacteriorhodopsin photocycle from time-resolved infrared spectra. Biochemistry 39:13189-200 |
| Dioumaev, A K; Braiman, M S (1997) Nano- and microsecond time-resolved FTIR spectroscopy of the halorhodopsin photocycle. Photochem Photobiol 66:755-63 |
| Braiman, M S; Dioumaev, A K; Lewis, J R (1996) A large photolysis-induced pKa increase of the chromophore counterion in bacteriorhodopsin: implications for ion transport mechanisms of retinal proteins. Biophys J 70:939-47 |
| Mitrovich, Q M; Victor, K G; Braiman, M S (1995) Differences between the photocycles of halorhodopsin and the acid purple form of bacteriorhodopsin analyzed with millisecond time-resolved FTIR spectroscopy. Biophys Chem 56:121-7 |
