𝔖 Bobbio Scriptorium
✦   LIBER   ✦

17O NMR chemical shifts of the twenty protein amino acids in aqueous solution

✍ Scribed by Ioannis P. Gerothanassis; Roger N. Hunston; JÜRgen Lauterwein

Publisher
John Wiley and Sons
Year
1985
Tongue
English
Weight
882 KB
Volume
23
Category
Article
ISSN
0749-1581

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The ^17^O chemical shifts of the α‐carboxyl groups of the protein amino acids, including 4‐hydroxyproline, sarcosine and N,N‐dimethylglycine, were measured at 40°C in aqueous solution at variable pH (^17^O enrichment 10 atom‐%). The chemical shifts of the amino acids were found to be between 250 and 257 ppm at low pH and between 266 and 273 ppm at neutral pH. For the purpose of comparison, several aliphatic and halogen‐containing carboxylic acids have also been measured under identical conditions. The high‐frequency titration shifts observed on deprotonation of the α‐carboxyl oxygens of the amino acids (15‐17 ppm) are similar to those of α‐haloalkanoic acids. A linear correlation of the titration shifts and the p__K__~a~ values was found for the carboxylic acids, including the amino acids. The differences in the chemical shifts of the amino acids in either the cationic or zwitterionic state can be explained by the substituent effects of the side‐chains, introducing γ shielding and δ deshielding values of approximately half the size of those for aldehydes and ketones. Deprotonation of the primary α‐amino group of the amino acids induced low‐frequency shifts between ‐2.3 and ‐3.9 ppm, with the exception of serine and threonine (‐1.3 and ‐1.7 ppm, respectively). On deprotonation of the secondary α‐amino group of proline, 4‐hydroxyproline and sarcosine, a decrease in the titration shifts was observed (‐0.9, ‐0.2 and ‐1.1 ppm, respectively) and on deprotonation of the tertiary α‐amino group of N,N‐dimethylglycine the sign was reversed (+3.9 ppm). The titration shifts can be explained by an inductive shift to high frequency, which is counterbalanced by an electric field shift of variable magnitude to low frequency.

📜 SIMILAR VOLUMES

17O-NMR. of Enriched Acetic Acid, Glycin
17O-NMR. of Enriched Acetic Acid, Glycine, Glutamic Acid and Aspartic Acid in Aqueous Solution. I. Chemical Shift Studies
✍ Ioannis P. Gerothanassis; Roger Hunston; Jürgen Lauterwein 📂 Article 📅 1982 🏛 John Wiley and Sons 🌐 German ⚖ 576 KB

## Abstract The ^17^O‐NMR. chemical shifts of the enriched amino acids glycine, aspartic acid and glutamic acid were measured in aqueous solution as a function of pH. High magnetic fields are necessary to resolve the α, β‐ and α, γ‐carboxyl resonances of aspartic acid and glutamic acid, respectivel

Simulation of 59Co NMR Chemical Shifts i
Simulation of 59Co NMR Chemical Shifts in Aqueous Solution
✍ Michael Bühl; Sonja Grigoleit; Hendrik Kabrede; Frank T. Mauschick 📂 Article 📅 2006 🏛 John Wiley and Sons 🌐 English ⚖ 197 KB 👁 1 views

## Abstract ^59^Co chemical shifts were computed at the GIAO‐B3LYP level for [Co(CN)~6~]^3−^, [Co(H~2~O)~6~]^3+^, [Co(NH~3~)~6~]^3+^, and [Co(CO)~4~]^−^ in water. The aqueous solutions were modeled by Car–Parrinello molecular dynamics (CPMD) simulations, or by propagation on a hybrid quantum‐mechan

17O-NMR. of Enriched Acetic Acid, Glycin
17O-NMR. of Enriched Acetic Acid, Glycine, Glutamic Acid and Aspartic Acid in Aqueous Solution. II. Relaxation Studies
✍ Ioannis P. Gerothanassis; Roger Hunston; Jürgen Laulenvein 📂 Article 📅 1982 🏛 John Wiley and Sons 🌐 German ⚖ 607 KB

## Abstract The ^17^O‐NMR. line widths of the enriched amino acids glycine, aspartic acid, glutamic acid and, for comparative reasons, acetic acid were measured in aqueous solution between pH 1 and 14. The ^17^O‐NMR. line‐width maxima of glycine at pH≈︁11 and acetic acid at pH≈︁5 are shown to arise

Carbon-13 NMR chemical shifts of the com
Carbon-13 NMR chemical shifts of the common amino acid residues measured in aqueous solutions of the linear tetrapeptides H-Gly-Gly- X-L- Ala-OH
✍ René Richarz; Kurt Wüthrich 📂 Article 📅 1978 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 483 KB 👁 1 views

## Abstract The ^13^C nmr chemical shifts of the common amino acid residues were measured in D~2~O solutions of the linear tetrapeptides H‐Gly‐Gly‐X‐L‐Ala‐OH. For Asp, Glu, Lys, Tyr and His, the titration shifts arising from the ionization of te amino acid side chains were also obtained. These data

Study of the behaviour of amino acids in
Study of the behaviour of amino acids in aqueous solution by time-domain NMR and high-resolution NMR
✍ M. Khallouk; D. N. Rutledge; A. M. S. Silva; I. Delgadillo 📂 Article 📅 2005 🏛 John Wiley and Sons 🌐 English ⚖ 189 KB

## Abstract The study of protein hydration by time‐domain NMR is complicated by the great number of interactions involved, resulting from the presence of several amino acids and the possible modifications produced by the various structures. Moreover, a good comprehension of the molecular interactio