Detecting O2 binding sites in protein cavities.

ABSTRACT: Internal cavities are important elements in protein structure, dynamics, stability and function. Here we use NMR spectroscopy to investigate the binding of molecular oxygen (O2) to cavities in a well-studied model for ligand binding, the L99A mutant of T4 lysozyme. On increasing the O2 concentration to 8.9 mM, changes in (1)H, (15)N, and (13)C chemical shifts and signal broadening were observed specifically for backbone amide and side chain methyl groups located around the two hydrophobic cavities of the protein. O2-induced longitudinal relaxation enhancements for amide and methyl protons could be adequately accounted for by paramagnetic dipolar relaxation. These data provide the first experimental demonstration that O2 binds specifically to the hydrophobic, and not the hydrophilic cavitie

SUBMITTER: Kitahara R 

PROVIDER: S-EPMC4735865 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature