| Version | Summary | Created by | Modification | Content Size | Created at | Operation |
|---|---|---|---|---|---|---|
| 1 | Helena Kang | -- | 159 | 2026-10-09 08:23:30 |
Lewis-acid surfaces of metal oxides, typically titanium dioxide or zirconium dioxide, that bind phosphate and related oxyanions define metal oxide affinity chromatography (MOAC). Phosphopeptides or phosphoproteins coordinate to the metal centers through their phosphate groups; non-phosphorylated species are washed away, and the bound phosphopeptides are eluted with base or competing anions [1]. Tandem or hybrid materials combine MOAC with immobilized-metal affinity chromatography (IMAC) to broaden coverage, but the MOAC step remains oxide-surface coordination rather than chelated-metal coordination [2]. Conceptual boundaries exclude IMAC on Ni(II)- or Fe(III)-NTA resins, ordinary adsorption chromatography on silica, and ion-exchange chromatography. Essential features are a high-surface-area metal oxide, a loading buffer that favors phosphate–oxide binding, and an elution condition that releases the phosphate without destroying the peptide [3]. Two-dimensional titania–graphene and related nanohybrids are still MOAC so long as the capturing surface is the metal oxide [4].