Analysis of O₂-binding Sites in Proteins Using Gas-Pressure NMR Spectroscopy: Outer Surface Protein A.

ABSTRACT: Internal cavities in proteins produce conformational fluctuations and enable the binding of small ligands. Here, we report a NMR analysis of O₂-binding sites by O₂-induced paramagnetic relaxation enhancements (PREs) on amide groups of proteins in solution. Outer surface protein A contains a nonglobular single-layer β-sheet that connects the N- and C-terminal globular domains. Several cavities have been observed in both domains of the crystallized protein structure. The receptor-binding sites are occluded and line the largest cavity of the C-terminal domain. We observed significant O₂-induced PREs for amide protons located around the largest cavity and at the central β-sheet. We suggested three potential O₂-accessible sites in the protein based on

SUBMITTER: Kawamura T 

PROVIDER: S-EPMC5425398 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature