Perovskite for the highly selective enrichment of phosphopeptides

Selective and effective enrichment of phosphopeptides from complex samples is essential in phosphoproteome study by mass spectrometry (MS). In this work, we compared perovskites (MgTiO 3 , CaTiO 3 , SrTiO 3 , BaTiO 3 and CaZrO 3 ) with metal oxides (ZrO 2 and TiO 2 ) in their capability for the selective enrichment of phosphopeptides. It was found here that perovskites exhibited higher selectivity towards phosphopeptides than commonly used ZrO 2 and TiO 2 , even though they all have high affinity to phosphopeptides. As for perovskites, CaTiO 3 exhibited better selectivity for enrichment of phosphopeptides than SrTiO 3 , MgTiO 3 , BaTiO 3 and CaZrO 3 , which might be ascribed to their crystal structures and electrophilic abilities. Moreover, to further confirm the performance of CaTiO 3 , CaTiO 3 and TiO 2 were applied to the enrichment of phosphopeptides from tryptic digest of proteins of human Jurkat-T cell lysate, respectively. The results showed CaTiO 3 has much higher selectivity than TiO 2 in the enrichment of phosphopeptides from the complex biological sample. Taken together, here we show that CaTiO 3 is an excellent material for the highly selective enrichment of phosphopeptides and it could be potentially used in the large-scale phosphoproteome study.