Here we describe a new method to identify calcium-binding sites in proteins using high-resolution liquid chromatography- mass spectrometry in concert with calcium-directed collision-induced dissociations. Our method does not require any modifications to the liquid chromatography- mass spectrometry apparatus, uses standard digestion protocols, and can be applied to existing high-resolution MS data files. In contrast to NMR, our method is applicable to very small amounts of complex protein mixtures (femtomole level). Calcium-bound peptides can be identified using three criteria: (1) the calculated exact mass of the calcium containing peptide; (2) specific dissociations of the calcium-containing peptide from threonine and serine residues; and (3) the very similar retention times of the calcium-containing peptide and the free peptide.

dx.doi.org/10.1074/mcp.M114.038182, hdl.handle.net/1765/88367
Molecular and Cellular Proteomics
Department of Neurology

Jamalian, A, Sneekes, E.-J, Wienk, H, Dekker, L.J.M, Ruttink, P.J.A, Ursem, M, … Burgers, P.C. (2014). Identifying Ca2+-Binding sites in proteins by liquid chromatography-mass spectrometry using Ca2+-Directed dissociations. Molecular and Cellular Proteomics, 13(11), 3177–3183. doi:10.1074/mcp.M114.038182