Lanthanum silicate coated magnetic microspheres as a promising affinity material for phosphopeptide enrichment and identification.
Novel Fe(3)O(4)@La(x)Si(y)O(5) affinity microspheres consisting of a superparamagnetic Fe(3)O(4) core and an amorphous lanthanum silicate shell have been synthesized. The core-shell-structured Fe(3)O(4)@La(x)Si(y)O(5) microspheres, with a mean size of ca. 480 nm, had rough lanthanum silicate surfaces and displayed relatively strong magnetism (47.2 emu g(-1)). This novel affinity material can be used for selective capture, rapid magnetic separation, and part dephosphorylation (which plays an important role in identifying phosphopeptides in MS) of the phosphopeptides in a peptide mixture. Its ability to selectively trap and magnetically isolate as well as label the phosphopeptides was evaluated using a standard phosphorylated protein (β-casein) and a real sample (human serum). Phosphopeptides and their corresponding label ions were detected for concentrations of β-casein as low as 1 × 10(-9) M and in mixtures of β-casein and BSA with molar ratios as low as 1:50. In addition, this affinity material, with its labeling properties, is superior to commercial TiO(2) beads in terms of interference from non-phosphopeptide molecules. These results reveal that the lanthanum silicate coated magnetic microspheres represent a promising affinity material for the rapid purification and recognition of phosphopeptides.
College of Life Science, Shenzhen University, Shenzhen, China.
Gong
G
Cheng
Yan-Lin
YL
Liu
Ji-Lin
JL
Zhang
De-Hui
DH
Sun
Jia-Zuan
JZ
Ni
D000818:Animals; D002364:Caseins / Q000032:analysis / Q000737:chemistry; D002417:Cattle; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006801:Humans; D007811:Lanthanum / Q000737:chemistry*; D059346:Magnets; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D010748:Phosphopeptides / Q000302:isolation & purification*; D010766:Phosphorylation; D012710:Serum Albumin, Bovine / Q000032:analysis; D017640:Silicates / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013499:Surface Properties
D002364:Caseins; D010748:Phosphopeptides; D017640:Silicates; D012710:Serum Albumin, Bovine; D007811:Lanthanum; D052203:Ferrosoferric Oxide