title: NMR-based localization of ions involved in salting out of hen egg white lysozyme.
abstract: NaCl-induced aggregation of hen egg white lysozyme (HEWL) was monitored by NMR spectroscopy. Small, but significant, changes induced by salt addition in TOCSY spectra were attributed to the effect of local reorganization of protein backbone upon ion binding. Salt-induced variations in HN and H alpha chemical shifts were mapped on the HEWL 3D structure which allowed the construction of a scheme of the spatial localization of potential ion binding sites. It was found that in a 0.5 M NaCl solution six chloride anions and at least one sodium cation are bound to preferred sites on the HEWL surface.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa, Poland. jarek@ichf.edu.pl
authors.forename: Jarosław
authors.initials: J
authors.lastname: Poznański
mesh_terms: D000818:Animals; D001665:Binding Sites; D002645:Chickens; D004529:Egg White; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation / Q000187:drug effects; D017433:Protein Structure, Secondary; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D012965:Sodium Chloride; C421864:hen egg lysozyme; D009113:Muramidase