In situ NMR measurement of macromolecule-bound metal ion concentrations.
Many nucleic acids and proteins require divalent metal ions such as Mg(2+) and Ca(2+) for folding and function. The lipophilic alignment media frequently used as membrane mimetics also bind these divalent metals. Here we demonstrate the use of (31)P NMR spectrum of a metal ion chelator (deoxycytidine diphosphate) to measure the bound [Mg(2+)] and [Ca(2+)] in situ for several biological model systems at relatively high divalent ion concentrations (1-10 mM). This method represents a general approach to measuring divalent metal ion binding in NMR samples where the amount and type of metal ion added to the system is known.
Department of Chemistry, University of California, Irvine, CA, 92697, USA.
Natalia
N
Kozlyuk
Department of Chemistry, University of California, Irvine, CA, 92697, USA.
Suvrajit
S
Sengupta
Department of Chemistry, University of California, Irvine, CA, 92697, USA. aluptak@uci.edu.|Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697, USA. aluptak@uci.edu.|Department of Pharmaceutical Sciences, University of California, Irvine, CA, 92697, USA. aluptak@uci.edu.
Andrej
A
Lupták
Department of Chemistry, University of California, Irvine, CA, 92697, USA. rwmartin@uci.edu.|Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697, USA. rwmartin@uci.edu.
Rachel W
RW
Martin
D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008670:Metals / Q000737:chemistry*; D013696:Temperature
D007477:Ions; D046911:Macromolecular Substances; D008670:Metals
31P NMR; Bicelles; Ca2+ dependent protein; Dickerson dodecamer; Divalent ion concentration; dCDP; βγ-Crystallin