title: Quantification of H/D isotope effects on protein hydrogen-bonds by h3JNC' and 1JNC' couplings and peptide group 15N and 13C' chemical shifts.
abstract: The effect of hydrogen/deuterium exchange on protein hydrogen bond coupling constants (h3)J(NC') has been investigated in the small globular protein ubiquitin. The couplings across deuterated or protonated hydrogen bonds were measured by a long-range quantitative HA(CACO)NCO experiment. The analysis is combined with a determination of the H(N)/D(N) isotope effect on the amide group (1)J(NC') couplings and the (15)N and (13)C' chemical shifts. On average, H-bond deuteration exchange weakens (h3)J(NC') and strengthens (1)J(NC') couplings. A correlation is found between the size of the (15)N isotope shift, the (15)N chemical shift, and the (h3)J(NC') coupling constants. The data are consistent with a reduction of donor-acceptor overlap as expected from the classical Ubbelohde effect and the common understanding that H(N)/D(N) exchange leads to a shortening of the N-hydron bond length.
authors.affiliation: Division of Structural Biology, Biozentrum der Universität Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.
authors.forename: Victor A
authors.initials: VA
authors.lastname: Jaravine
authors.forename: Florence
authors.initials: F
authors.lastname: Cordier
authors.forename: Stephan
authors.initials: S
authors.lastname: Grzesiek
mesh_terms: D002244:Carbon / Q000737:chemistry; D003903:Deuterium / Q000737:chemistry; D004583:Electrons; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D016014:Linear Models; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D011522:Protons; D013696:Temperature; D025801:Ubiquitin / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D010455:Peptides; D011522:Protons; D025801:Ubiquitin; D014867:Water; D002244:Carbon; D006859:Hydrogen; D003903:Deuterium; D009584:Nitrogen