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 …

The principal values of the 15N chemical shift tensors of crystalline histidine and histidine-
containing peptides have been measured to document for the first time the systematic trends …

The histidine imidazole side chain plays a critical role in protein function and stability. Its
importance for catalysis is underscored by the fact that histidines are localized to active sites …

A method is proposed to determine the fraction of the tautomeric forms of the imidazole ring
of histidine in proteins as a function of pH, provided that the observed and chemical shifts …

If the 13Cδ2 chemical shift of neutral (“high pH”) histidine is> 122 ppm, primarily Nδ1− H
tautomer (2) is indicated; if it is< 122 ppm, primarily Nε2− H tautomer (1) is indicated. His …

Histidine is an important natural amino acid, involved in many relevant biological processes,
which, because of its physical properties, proved difficult to characterize experimentally in its …

The imidazole group of a histidine side chain has four different protonation forms, ie, the two
neutral tautomers (N1-and N3-protonated forms), imidazolium cation, and imidazolate anion …

Acid− base properties of lyophilized powders of l-histidine have been systematically
investigated using parent solutions at pH varying from 1.8 to 10. For the first time, high …

Weak hydrogen bonding in uracil and 4-cyano-4 '-ethynylbiphenyl, for which single-crystal
diffraction structures reveal close CH⊙⊙⊙ OC and C⋮ CH⊙⊙⊙ N⋮ C distances, is …

Cross-correlation between 15N− 1H dipolar interactions and 1HN chemical shift anisotropy
(CSA) gives rise to different relaxation rates of the doublet components of 1H−{15N} peptide …