In situ NMR measurement of macromolecule-bound metal ion concentrations

Natalia Kozlyuk; Suvrajit Sengupta; Andrej Lupták; Rachel W Martin

doi:10.1007/s10858-016-0031-3

In situ NMR measurement of macromolecule-bound metal ion concentrations

J Biomol NMR. 2016 Apr;64(4):269-73. doi: 10.1007/s10858-016-0031-3. Epub 2016 Apr 23.

Authors

Natalia Kozlyuk¹, Suvrajit Sengupta¹, Andrej Lupták^{2

3

4}, Rachel W Martin^{5

6}

Affiliations

¹ Department of Chemistry, University of California, Irvine, CA, 92697, USA.
² Department of Chemistry, University of California, Irvine, CA, 92697, USA. aluptak@uci.edu.
³ Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697, USA. aluptak@uci.edu.
⁴ Department of Pharmaceutical Sciences, University of California, Irvine, CA, 92697, USA. aluptak@uci.edu.
⁵ Department of Chemistry, University of California, Irvine, CA, 92697, USA. rwmartin@uci.edu.
⁶ Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, 92697, USA. rwmartin@uci.edu.

PMID: 27108020
DOI: 10.1007/s10858-016-0031-3

Abstract

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.

Keywords: 31P NMR; Bicelles; Ca2+ dependent protein; Dickerson dodecamer; Divalent ion concentration; dCDP; βγ-Crystallin.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Hydrogen-Ion Concentration
Ions / chemistry*
Macromolecular Substances / chemistry*
Magnetic Resonance Spectroscopy*
Metals / chemistry*
Temperature

Substances

Ions
Macromolecular Substances
Metals