English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Hydrogen bonding between an amide group and the p-π cloud ofan aromatic ring was first identified in a protein in the 1980s. Subsequentsurveys of high-resolution X-ray crystal structures found multipleinstances, but their preponderance was determined to be infrequent. Hydrogen atoms participating in a hydrogen bond to the p-π cloud of an aromaticring are expected to experience an upfield chemical shift arising from ashielding ring current shift. We surveyed the Biological Magnetic ResonanceData Bank for amide hydrogens exhibiting unusual shifts as well ascorroborating nuclear Overhauser effects between the amide protons and ringprotons. We found evidence that Trp residues are more likely to be involvedin p-π hydrogen bonds than other aromatic amino acids, whereas Hisresidues are more likely to be involved in in-plane hydrogen bonds, with aring nitrogen acting as the hydrogen acceptor. The p-π hydrogen bondsmay be more abundant than previously believed. The inclusion in NMRstructure refinement protocols of shift effects in amide protons fromaromatic sidechains, or explicit hydrogen bond restraints between amidesand aromatic rings, could improve the local accuracy of sidechainorientations in solution NMR protein structures, but their impact on globalaccuracy is likely be limited.

Anomalous amide proton chemical shifts as signatures of hydrogen bonding to aromatic sidechains