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Four‐bond deuterium isotope effects on the chemical shifts of amide nitrogens in proteins
Author(s) -
Tugarinov Vitali
Publication year - 2013
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.4007
Subject(s) - chemistry , deuterium , kinetic isotope effect , chemical shift , amide , deuterium nmr , isotope , nitrogen , proton , crystallography , nuclear magnetic resonance spectroscopy , stereochemistry , organic chemistry , physics , quantum mechanics
An approach towards precision NMR measurements of four‐bond deuterium isotope effects on the chemical shifts of backbone amide nitrogen nuclei in proteins is described. Three types of four‐bond 15 N deuterium isotope effects are distinguished depending on the site of proton‐to‐deuterium substitution: 4 ΔN(N i‐1 D), 4 ΔN(N i+1 D) and 4 ΔN(C β ,i‐1 D). All the three types of isotope shifts are quantified in the (partially) deuterated protein ubiquitin. The 4 ΔN(N i+1 D) and 4 ΔN(C β ,i‐1 D) effects are by far the largest in magnitude and vary between 16 and 75 ppb and −18 and 46 ppb, respectively. A semi‐quantitative correlation between experimental 4 ΔN(N i+1 D) and 4 ΔN(C β ,i‐1 D) values and the distances between nitrogen nuclei and the sites of 1 H‐to‐D substitution is noted. The largest isotope shifts in both cases correspond to the shortest inter‐nuclear distances. Copyright © 2013 John Wiley & Sons, Ltd.