Topic
Hydrogen bond
About: Hydrogen bond is a research topic. Over the lifetime, 57701 publications have been published within this topic receiving 1306326 citations.
Papers published on a yearly basis
Papers
More filters
362 citations
TL;DR: High-resolution three-dimensional structural analyses of yeast iso-1-cytochrome c have now been completed in both oxidation states using isomorphous crystalline material and similar structure determination methodologies, showing that oxidation state-dependent changes are expressed for the most part in terms of adjustments to heme structure, movement of internally bound water molecules and segmental thermal parameter changes along the polypeptide chain.
361 citations
TL;DR: Changes in conformation of oligosaccharides, and the constraints imposed by hydrogen bonding with the solvent, were studied by means of vibrational spectroscopy (FTIR-ATR and laser-Raman).
361 citations
TL;DR: Amide proton temperature coefficients offer an attractive and simple way to confirm existence of hydrogen bonds in NMR determined structures and do not change with pH unless they correspond to conformational changes.
Abstract: Correlations between amide proton temperature coefficients (deltasigmaHN/deltaT) and hydrogen bonds were investigated for a data set of 793 amides derived from 14 proteins. For amide protons showing temperature gradients more positive than -4.6 ppb/K there is a hydrogen bond predictivity value exceeding 85%. It increases to over 93% for amides within the range between -4 and -1 ppb/K. Detailed analysis shows an inverse proportionality between amide proton temperature coefficients and hydrogen bond lengths. Furthermore, for hydrogen bonds of similar bond lengths, values of temperature gradients in alpha-helices are on average I ppb/K more negative than in beta-sheets. In consequence. a number of amide protons in alpha-helices involved in hydrogen bonds shorter than 2 A show deltasigmaHN/deltaT < -4.6 ppb/K. Due to longer hydrogen bonds, 90% of amides in 3(10) helices and 98% in beta-turns have temperature coefficients more positive than -4.6ppb/K. Ring current effect also significantly influences temperature coefficients of amide protons. In seven out of eight cases non-hydrogen bonded amides strongly deshielded by neighboring aromatic rings show temperature coefficients more positive than -2 ppb/K. In general, amide proton temperature gradients do not change with pH unless they correspond to conformational changes. Three examples of pH dependent equilibrium showing hydrogen bond formation at higher pH were found. In conclusion, amide proton temperature coefficients offer an attractive and simple way to confirm existence of hydrogen bonds in NMR determined structures.
360 citations
TL;DR: The crystal structure of bovine carboxypeptidase A (Cox) has been refined at 1.54 A resolution using the restrained least-squares algorithm of Hendrickson & Konnert (1981) and four examples of a reverse turn like structure requiring an aspartic acid or asparagine residue are observed in this structure.
359 citations