Utilization of ¹³C-labeled amino acids to probe the α-helical local secondary structure of a membrane peptide using electron spin echo envelope modulation (ESEEM) spectroscopy.

ABSTRACT: Electron spin echo envelope modulation (ESEEM) spectroscopy in combination with site-directed spin labeling (SDSL) has been established as a valuable biophysical technique to provide site-specific local secondary structure of membrane proteins. This pulsed electron paramagnetic resonance (EPR) method can successfully distinguish between α-helices, β-sheets, and 3₁₀-helices by strategically using ²H-labeled amino acids and SDSL. In this study, we have explored the use of ¹³C-labeled residues as the NMR active nuclei for this approach for the first time. ¹³C-labeled d₅-valine (Val) or ¹³C-labeled d₆-leucine (Leu) were substituted at a specific Val or Leu residue (i), and a nitroxide spin label was positioned 2 or 3

SUBMITTER: Bottorf L 

PROVIDER: S-EPMC5957090 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature