title: Detection of salt bridges to lysines in solution in barnase.
abstract: We show that salt bridges involving lysines can be detected by deuterium isotope effects on NMR chemical shifts of the sidechain amine. Lys27 in the ribonuclease barnase is salt bridged, and mutation of Arg69 to Lys retains a partially buried salt bridge. The salt bridges are functionally important.
authors.affiliation: Dept of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK. m.williamson@sheffield.ac.uk.
authors.forename: Mike P
authors.initials: MP
authors.lastname: Williamson
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Hounslow
authors.forename: Joe
authors.initials: J
authors.lastname: Ford
authors.forename: Kyle
authors.initials: K
authors.lastname: Fowler
authors.forename: Max
authors.initials: M
authors.lastname: Hebditch
authors.forename: Poul Erik
authors.initials: PE
authors.lastname: Hansen
mesh_terms: D001426:Bacterial Proteins; D003903:Deuterium / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008239:Lysine / Q000032:analysis* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D008958:Models, Molecular; D012015:Reference Standards; D012260:Ribonucleases / Q000737:chemistry* / Q000378:metabolism; D012492:Salts / Q000032:analysis* / Q000378:metabolism; D012996:Solutions
chemical_list: D001426:Bacterial Proteins; D012492:Salts; D012996:Solutions; D003903:Deuterium; D012260:Ribonucleases; C019760:Bacillus amyloliquefaciens ribonuclease; D008239:Lysine