Aluminium glycinate functionalized silica nanoparticles for highly specific separation of phosphoproteins

Abstract

Selective separation of intact phosphoproteins from complex biological samples is essential for the ongoing top-down phosphoproteomics, but challenges still remain. Herein, aluminium hydroxide functionalized silica nanoparticles (denoted as AGNP) was synthesized by a facile approach and applied for specific capture of phosphoproteins. The selectivity and binding capacity of AGNP were evaluated by using caseins (α-casein and β-casein) as phosphoproteins and nonphosphoproteins (bovine haemoglobin, bovine serum albumin, horseradish peroxidase, myoglobin and lysozyme) as nonphoproteins. The results indicated that the AGNP showed high bind-ing capacity and selectivity for phosphpproteins (αcasein 1190 mg g -1 and β-casein 1060 mg g -1 ). In addi-tion, the AGNP can be used to selectively capture and enrich phosphpproteins from protein mixture and drinking milk samples. The good results demonstrate the potential of the AGNP in phosphoproteomics analysis.Aluminium hydroxide functionalized silica nanoparticles was synthesized by a facile approach and successfully applied for specific capture of phosphoproteins from complex sample.

Enrichment of intact phosphoproteins using immobilized titanium(IV) affinity chromatography microspheres

“…As illustrated in Figure A, Ti 4+ ‐IMAC has higher adsorption capacity for β‐casein than BSA; the saturated adsorption capacity for β‐casein (925.9 mg/g) is more than 15‐fold higher than that of BSA (60.3 mg/g), which demonstrates the excellent phosphoprotein enrichment ability of Ti 4+ ‐IMAC. Comparing with similar phosphoprotein enrichment materials, the adsorption capacity for β‐casein of Ti 4+ ‐IMAC is nearly the same as that of materials published before and larger than that of Ti 4+ ‐immobilized affinity silica nanoparticles . What's more, the Langmuir model was well fitted for the adsorption behaviors of these proteins under the adopted concentration range (Figure B).…”

“…Yang et al. synthesized aluminium (Al 3+ ) glycinate functionalized silica nanoparticles with a β‐casein binding capacity of 1060 mg/g, and enrichment performance in 10‐fold diluted drinking milk was also evaluated . Wu et al.…”

“…Jia et al synthesized and applied the polydopamine assisted Ti 4+ -decorated magnetic particles for selective enrichment caseins (α-, β-, and κ-) out of 10-fold diluted non-fat milk, and a β-casein adsorption capacity of 1273.9 mg/g was measured [26]. Yang et al synthesized aluminium (Al 3+ ) glycinate functionalized silica nanoparticles with a β-casein binding capacity of 1060 mg/g, and enrichment performance in 10-fold diluted drinking milk was also evaluated [27]. Wu et al prepared Ti 4+ -immobilized affinity silica nanoparticles with a β-casein adsorption capacity of 328.9 mg/g, intact phosphoproteins enrichment was tested with a standard protein mixture (β-casein/BSA/lysozyme, 3:1:1, w/w) as well as 50-fold and 10-fold diluted drinking milk [28].…”

Facile synthesis of titanium(IV) ion‐immobilized poly‐glycidyl methacrylate microparticles functionalized with polyethylenimine and adenosine triphosphate for highly specific enrichment of intact phosphoproteins

“…According to the slope of linear fit curve, the saturated adsorption capacity for β‐casein and BSA was calculated to be 1217.6 and 97.1 mg/g, respectively. Ti 4+ ‐ATP‐PEI‐MPs possessed higher adsorption capacity toward phosphoproteins than Fe 3 O 4 ‐SiO 2 ‐GDN , SiO 2 ‐Ti NPs , and AGNP . The large adsorption capacity of Ti 4+ ‐ATP‐PEI‐MPs for intact phosphoproteins explains their excellent enrichment performance, in contrast, the small adsorption capacity for nonphosphoproteins demonstrates good enrichment selectivity.…”

Phosphoproteomics in the Age of Rapid and Deep Proteome Profiling

“…Liu et al, employing a hydrophilic antacid aluminum glycinate functionalization for phosphate group affinity, also described nanoparticles for phosphoprotein enrichment. 47 Interestingly, Hoehenwarter et al combined intact phosphoprotein enrichment with aluminum oxide (Al(OH) 3 ) with subsequent tryptic digestion and standard TiOx phosphopeptide enrichment to study mitogen-activated protein kinase substrates in Arabidopsis . 48 Because proteomics of intact proteins, especially of phosphoproteins, in complex mixtures is still a maturing field, many of these protocols have yet to see widespread use that could provide insight into their reproducibility or utility in routine experiments.…”