Protonation, tautomerization, and rotameric structure of histidine: a comprehensive study by magic-angle-spinning solid-state NMR.

ABSTRACT: Histidine structure and chemistry lie at the heart of many enzyme active sites, ion channels, and metalloproteins. While solid-state NMR spectroscopy has been used to study histidine chemical shifts, the full pH dependence of the complete panel of (15)N, (13)C, and (1)H chemical shifts and the sensitivity of these chemical shifts to tautomeric structure have not been reported. Here we use magic-angle-spinning solid-state NMR spectroscopy to determine the (15)N, (13)C, and (1)H chemical shifts of histidine from pH 4.5 to 11. Two-dimensional homonuclear and heteronuclear correlation spectra indicate that these chemical shifts depend sensitively on the protonation state and tautomeric structure. The chemical shifts of the rare π tautomer were observed for the first time, at the most basic pH

SUBMITTER: Li S 

PROVIDER: S-EPMC4082993 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature