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Protein Phosphorylation
Resin Elution Selectivity
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Product No: P 9740
Resin Elution Selectivity - MALDI-MS
Figure 2. MALDI mass spectra of A) Crude ß-casein tryptic digest (113 pmol/µL) prior to loading on the PHOS-Select Resin and B)-E) purified phosphopeptides after elution from the PHOS-Select Resin under various elution conditions. Eluents were as follows: B) 0.15 M NH4OH, C) 0.4 M NH4OH, neutralized with formic acid prior to analysis, D) 0.15 M NH4OH, 25% ACN, and E) 5% formic acid, 25% ACN.
| Binding Capacity Study |
| Species |
Molecular
Weight (Da) |
Format |
Plate
(nmol/well) |
Resin
(µmol/mL) |
4-methylumbelliferyl
phosphate (MUP) |
256.14 |
0.9 |
4.5 |
Monophosphopeptide
(ß-casein) |
2061.96 |
0.5 |
8.0 |
Tetraphosphopeptide
(ß-casein) |
3122.92 |
1.0 |
5.5 |
Binding capacities for the two formats were determined using purified phosphorylated molecules. Binding of MUP was determined via a fluorescence assay. Binding of the mono and tetraphosphopeptides was determined using HPLC-MS analysis.
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