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Determining ?-helical and ?-sheet secondary structures via pulsed electron spin resonance spectroscopy.

ABSTRACT: A new method has been developed to determine ?-helical and ?-sheet secondary structural components of aqueous and membrane-bound proteins using pulsed electron paramagnetic resonance (EPR) spectroscopy. The three-pulse electron spin echo envelope modulation (ESEEM) technique was used to detect weakly coupled (2)H-labeled nuclei on side chains in the proximity of a strategically placed nitroxide spin-label up to 8 Å away. Changes in the ESEEM spectra for different samples correlate directly to periodic structural differences between ?-helical and ?-sheet motifs. These distinct trends were demonstrated with ?-helical (M2? subunit of the acetylcholine receptor) and ?-sheet (ubiquitin) peptides in biologically relevant sample environments.

SUBMITTER: Zhou A

PROVIDER: S-EPMC3535504 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature

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Determining α-helical and β-sheet secondary structures via pulsed electron spin resonance spectroscopy.

Zhou Andy A Abu-Baker Shadi S Sahu Indra D ID Liu Lishan L McCarrick Robert M RM Dabney-Smith Carole C Lorigan Gary A GA

Biochemistry 20120914 38

A new method has been developed to determine α-helical and β-sheet secondary structural components of aqueous and membrane-bound proteins using pulsed electron paramagnetic resonance (EPR) spectroscopy. The three-pulse electron spin echo envelope modulation (ESEEM) technique was used to detect weakly coupled (2)H-labeled nuclei on side chains in the proximity of a strategically placed nitroxide spin-label up to 8 Å away. Changes in the ESEEM spectra for different samples correlate directly to pe ...[more]

PMID: 22966895

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