Enrichment and analysis of phosphopeptides under different experimental conditions using titanium dioxide affinity chromatography and mass spectrometry.
Rapid Commun Mass Spectrom
; 24(2): 219-31, 2010 Jan.
Article
en En
| MEDLINE
| ID: mdl-20014058
ABSTRACT
Titanium dioxide metal oxide affinity chromatography (TiO(2)-MOAC) is widely regarded as being more selective than immobilized metal-ion affinity chromatography (IMAC) for phosphopeptide enrichment. However, the widespread application of TiO(2)-MOAC to biological samples is hampered by conflicting reports as to which experimental conditions are optimal. We have evaluated the performance of TiO(2)-MOAC under a wide range of loading and elution conditions. Loading and stringent washing of peptides with strongly acidic solutions ensured highly selective enrichment for phosphopeptides, with minimal carryover of non-phosphorylated peptides. Contrary to previous reports, the addition of glycolic acid to the loading solution was found to reduce specificity towards phosphopeptides. Base elution in ammonium hydroxide or ammonium phosphate provided optimal specificity and recovery of phosphorylated peptides. In contrast, elution with phosphoric acid gave incomplete recovery of phosphopeptides, whereas inclusion of 2,5-dihydroxybenzoic acid in the eluant introduced a bias against the recovery of multiply phosphorylated peptides. TiO(2)-MOAC was also found to be intolerant of many reagents commonly used as phosphatase inhibitors during protein purification. However, TiO(2)-MOAC showed higher specificity than immobilized gallium (Ga(3+)), immobilized iron (Fe(3+)), or zirconium dioxide (ZrO(2)) affinity chromatography for phosphopeptide enrichment. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was more effective in detecting larger, multiply phosphorylated peptides than liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS), which was more efficient for smaller, singly phosphorylated peptides.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Fosfopéptidos
/
Espectrometría de Masas
/
Caseínas
/
Cromatografía de Afinidad
Tipo de estudio:
Diagnostic_studies
/
Evaluation_studies
Límite:
Animals
Idioma:
En
Revista:
Rapid Commun Mass Spectrom
Año:
2010
Tipo del documento:
Article