01967nas a2200349 4500008004500000020001400045245009200059210006900151260000800220300001400228490000700242520094400249653001501193653002101208653002701229653001201256653002701268653002101295653003401316653002301350653003001373653002601403653002201429653001401451100001301465700001401478700001701492700001701509700002001526700002201546856004901568 2008 Engldsh a0006-349500aTerahertz spectroscopy of bacteriorhodopsin and rhodopsin: Similarities and differences0 aTerahertz spectroscopy of bacteriorhodopsin and rhodopsin Simila cApr a3217-32260 v943 a
We studied the low-frequency terahertz spectroscopy of two photoactive protein systems, rhodopsin and bacteriorhodopsin, as a means to characterize collective low-frequency motions in helical transmembrane proteins. From this work, we found that the nature of the vibrational motions activated by terahertz radiation is surprisingly similar between these two structurally similar proteins. Specifically, at the lowest frequencies probed, the cytoplasmic loop regions of the proteins are highly active; and at the higher terahertz frequencies studied, the extracellular loop regions of the protein systems become vibrationally activated. In the case of bacteriorhodopsin, the calculated terahertz spectra are compared with the experimental terahertz signature. This work illustrates the importance of terahertz spectroscopy to identify vibrational degrees of freedom which correlate to known conformational changes in these proteins.
10aBiophysics10abovine rhodopsin10aconformational-changes10aelastic10afrequency normal-modes10alight activation10amolecular-dynamics simulation10aneutron-scattering10aprotein-coupled receptors10atransmembrane helices10avibrational-modes10awild-type1 aBalu, R.1 aZhang, H.1 aZukowski, E.1 aChen, J., Y.1 aMarkelz, A., G.1 aGregurick, S., K. uhttps://markelz.physics.buffalo.edu/node/222