PhoX, also known as (3,5-bis(((2,5-dioxopyrrolidin-1-yl)oxy) carbonyl)phenyl)phosphonic acid
It is a crosslinker used to study protein structures and interactions by means of Cross-Linking Mass Spectrometry (XL-MS). PhoX is a novel and unique trifunctional crosslinker. Two N-hydroxysuccinimide (NHS) ester functions react rapidly and irreversible with amino functions in proteins, mainly neighboring lysine groups. The stable phosphonic acid function allows for the enrichment of mono- and crosslinked peptides by using the well-established immobilized metal affinity chromatography (IMAC).
Overview of the available crosslinkers is shown in the table below.
| DSAU | DSPU | DSBU | PhoX | |
| Type |
|
|
|
|
| Chain | C2 | C3 | C4 | |
| Chain length | ~7.7 Å | ~10.1 Å | ~12.5 Å | ~ 5 Å |
Examples of applications can be found in the following application notes and publications
- Steigenberger B et al. Benefits of Collisional Cross Section Assisted Precursor Selection (caps-PASEF) for Cross-linking Mass Spectrometry, Mol Cell Proteomics, 2020, doi: 10.1074/mcp.RA120.002094, Online ahead of print.
- Steigenberger B et al. PhoX: An IMAC-Enrichable Cross-Linking Reagent, ACS Cent Sci. 2019 Sep 25;5(9):1514-1522.
- Liu F. et al. Proteome-wide profiling of protein assemblies by cross-linking mass spectrometry, Nat Methods. 2015 Dec 12(12), 1179-84.
- Klykov, O. et al. Efficient and robust proteome-wide approaches for cross-linking mass spectrometry, Nat Protoc 2018 Dec 13, 2964–2990.
The purity is greater than 95%.
The product is supplied in 5 x 2 mg vials. Vials are aliquoted under argon and in a sealed foil envelop packed under argon with desiccant. It is recommended to store the product on arrival at -20 °C or less.
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