Silica–Lanthanum Oxide: Pioneer Composite of Rare-Earth Metal Oxide in Selective Phosphopeptides Enrichment

Abstract

Relying on the successful journey of metal oxides in phosphoproteomics, lanthanum oxide is employed for the engineering of an affinity material for phosphopeptide enrichment. The lanthanum oxide is chemically modified on the surface of silica and characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The obtained silica-lanthanum oxide composite is applied for the selective enrichment of phosphopeptides from tryptic digest of standard protein (α-casein, β-casein, and commercially available casein mixtures from bovine milk). The enriched entities are analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass spectroscopy (MS) results show that the silica-lanthanum oxide composite exhibits enhanced capability for phosphopeptide enrichment with sensitivity assessed to be 50 fmol. Sequence coverage of casein is interpreted showing successful recovery. As a real sample, a protein digest of nonfat milk is applied. Also, the ability of lanthanum in different formats is checked in the selective phosphopeptides enrichment. The composite holds promising future in economic ground as it also possesses the regenerative ability for repetitive use.

Aluminium glycinate functionalized silica nanoparticles for highly specific separation of phosphoproteins

“…[5][6][7][8][9][10][11][12] Nevertheless, this bottom-up proteomics also suffers from drawbacks such as loss of labile PTMs and sequence variants. 13 In contrast, top-down MS analysis of intact phosphoproteins could provide a better description of protein phosphorylation 14,15 and regain considerable attention with new MS instruments such as Fourier transform ion cyclotron resonance 16,17 and Orbitrap MS 18,19 .…”

Fishing the PTM proteome with chemical approaches using functional solid phases

“…Infrared (IR) spectroscopy was applied to study phosphate protonation on goethite (a-FeO(OH)) surfaces, revealing three different types of complexes: protonated and nonprotonated bridging bidentate and non-protonated monodentate between orthophosphate ions and surface Fe(III) of a-FeO(OH) particles in aqueous suspensions. 46 Subsequently, ZrO 2 , 47 53 were also evaluated for their ability to enrich phosphopeptides based on the same principle. 42 Phosphate ion adsorption from aqueous solutions onto thin films of colloidal TiO 2 has also been studied.…”

Development of new multifunctional terpolymer sorbent for proteomics applications

“…The immobilization of IMAC-polymer with La 3+ ions was based on the significant affinity towards phosphopeptides in the form of oxide, ion or composite (Jabeen et al, 2012;Saeed et al, 2013;Güzel et al, 2013). However, the specificity was compared with the more traditionally employed Fe 3+ .…”