A simple method for correction of circular dichroism spectra obtained from membrane-containing samples.

ABSTRACT: Circular dichroism (CD) spectroscopy is an important technique in structural biology for examining folding and conformational changes of proteins in solution. However, the use of CD spectroscopy in a membrane medium (and also in a nonhomogeneous medium) is limited by (i) high light scattering and (ii) differential scattering of incident left and right circularly polarized light, especially at shorter wavelengths (<200 nm). We report a novel methodology for estimating the distortion of CD spectra caused by light scattering for membrane-bound peptides and proteins. The method is applied to three proteins with very different secondary structures to illustrate the limits of its capabilities when calibrated with a simple soluble peptide ([Ac]ANLKALEAQKQKEQRQAAEELANAK[OH], standard peptide) with a balanced secondary structure. The method with this calibration standard was quite successful in estimating ?-helix but more limited when it comes to proteins with very high ?-sheet or ?-turn content.

SUBMITTER: Chakraborty H 

PROVIDER: S-EPMC3282530 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature