In situ NMR measurement of macromolecule-bound metal ion concentrations.
- Author(s): Kozlyuk, Natalia
- Sengupta, Suvrajit
- Lupták, Andrej
- Martin, Rachel W
- et al.
Published Web Locationhttps://doi.org/10.1007/s10858-016-0031-3
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.