DSAU (disuccinimidyl diacetic urea), also known as ureido-2,2´-diacetic acid bis(hydroxysuccinimide) ester
It is a urea-based crosslinker used to study protein structures and interactions by means of Cross-Linking Mass Spectrometry (XL-MS). This symmetrical urea derivate with two N-hydroxysuccinimide (NHS) ester functions reacts rapidly and irreversible with amino functions in proteins, mainly neighboring lysine groups. The chemical chain between both groups defines the distance between the crosslinked lysine functions and can have impact on the yield of intramolecular or intermolecular bioconjugates. The crosslinked protein contains the MS-cleavable urea moiety, which enables unambiguous identification of crosslinked proteins by tandem MS in combination with gas-fragmentation methods.
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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