Protein flexibility and conformational state: a comparison of collective vibrational modes of wild-type and D96N bacteriorhodopsin.

ABSTRACT: Far infrared (FIR) spectral measurements of wild-type (WT) and D96N mutant bacteriorhodopsin thin films have been carried out using terahertz time domain spectroscopy as a function of hydration, temperature, and conformational state. The results are compared to calculated spectra generated via normal mode analyses using CHARMM. We find that the FIR absorbance is slowly increasing with frequency and without strong narrow features over the range of 2-60 cm(-1) and up to a resolution of 0.17 cm(-1). The broad absorption shifts in frequency with decreasing temperature as expected with a strongly anharmonic potential and in agreement with neutron inelastic scattering results. Decreasing hydration shifts the absorption to higher frequencies, possibly resulting from decreased coupling mediated by

SUBMITTER: Whitmire SE 

PROVIDER: S-EPMC1303244 | biostudies-literature | 2003 Aug

REPOSITORIES: biostudies-literature