An efficient method for dephosphorylation of phosphopeptides by cerium oxide

Abstract

In this article, an effective method for dephosphorylation of phosphopeptides by cerium oxide is described. The dephosphorylation activity of cerium oxide was evaluated by two standard phosphopeptides and the phosphopeptides in digests of phosphoprotein alpha-casein and beta-casein. Results showed that the dephosphorylation of all the phosphopeptides was completed in 10 min, and temperature had little effect on the dephosphorylation, the dephosphorylation could be carried out at 0 degrees C, room temperature and 37 degrees C. The dephosphorylation mediated by cerium oxide can be attributed to Lewis acid and nucleophile activations. Advantages of using cerium oxide as catalyst for the dephosphorylation include: safe, simple, high catalytic activity, and no precise control of the treatment temperature. The method is valid for the phosphorylation of Ser, Thr and Tyr, and can be used for phosphoprotein analysis.

Cerium oxide nanoparticle: a remarkably versatile rare earth nanomaterial for biological applications

“…Interestingly, they observed that unlike the single nuclear complexes of cerium, the dephosphorylative activity of CeONP depends on the presence of Ce 3 þ sites and is inhibited when Ce 3 þ is converted to Ce 4 þ . This is contrary to the opinions of Qian and colleagues 68 who proposed a Ce 4 þ -mediated hydrolysis process. To fully understand the mechanism, additional research must be carried out.…”

“…Third, temperature has little effect on the dephosphorylation; hence, precise control of the treatment temperature is not required, which facilitates the treatment process. 68 In a later study, Kuchma et al 34 reported that many biologically relevant molecules with phosphate ester, excluding DNA, could be hydrolyzed by CeONP. Interestingly, they observed that unlike the single nuclear complexes of cerium, the dephosphorylative activity of CeONP depends on the presence of Ce 3 þ sites and is inhibited when Ce 3 þ is converted to Ce 4 þ .…”

“…67 Recent studies have shown that CeONP can hydrolyze phosphate ester bonds of many biologically relevant molecules. 46,68,69 Qian and colleagues 68 found that CeONP could efficiently mediate the dephosphorylation of phosphopeptides. As CeONP is a strong Lewis acid, the dephosphorylation effect can be mainly attributed to Lewis acid activation via coordination of phosphoryl oxygen to Ce 4 þ and nucleophile activation via coordination of hydroxyl to Ce 4 þ .…”

“…In addition, CeONP can be regarded as a multinuclear metal-oxygen complex, producing a multiple synergistic activation effect and achieving high catalytic activity. Qian and colleagues 68 also proposed several advantages of using CeONP to mediate the dephosphorylation of phosphopeptides. First, it is safe and simple, and can be removed by centrifugation after treatment.…”

Preparation and characterization of ceria‐zirconia composite for enrichment and identification of phosphopeptides

“…In this method, mass spectra of peptides before and after treatment with phosphatases were compared, and phosphopeptides were characterized as typical species presenting the unique mass shift owing to loss of 80 Da or n  80 Da. It is reported that ceria could efficiently mediate the dephosphorylation of phosphopeptides [28], and this ''solid phosphatase'' can be used as an alternative to alkaline phosphatase for dephosphorylation without introducing impurity. Therefore, we speculate that ceria-zirconia composites may not only provide good specificity for phosphopeptide, but also mediate the dephosphorylation of phosphopeptides.…”