Using ¹⁵N-ammonium to characterise and map potassium binding sites in proteins by NMR spectroscopy.

ABSTRACT: A variety of enzymes are activated by the binding of potassium ions. The potassium binding sites of these enzymes are very specific, but ammonium ions can often replace potassium ions in vitro because of their similar ionic radii. In these cases, ammonium can be used as a proxy for potassium to characterise potassium binding sites in enzymes: the (1) H,(15) N spin-pair of enzyme-bound (15) NH4 (+) can be probed by (15) N-edited heteronuclear NMR experiments. Here, we demonstrate the use of NMR spectroscopy to characterise binding of ammonium ions to two different enzymes: human histone deacetylase 8 (HDAC8), which is activated allosterically by potassium, and the bacterial Hsp70 homologue DnaK, for which potassium is an integral part of the active site. Ammonium activates both enzymes in a

SUBMITTER: Werbeck ND 

PROVIDER: S-EPMC4016748 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature