Can Sulfo-SBED be stored in a stock solution?
No. The crosslinker is moisture sensitive. The sulfo-NHS ester is easily hydrolyzed.
Is the crosslinker soluble in organic solutions as well as aqueous solutions?
Yes, Sulfo-SBED is soluble in aqueous as well as organic solutions. It is most soluble in organics such as DMF and DMSO.
What is the appropriate wavelength for the conjugation of the photoactivatable group?
UV light at wavelengths greater than 300 nm are appropriate for conjugation.
Which reaction should take place first?
The NHS-ester end of the crosslinker is subject to hydrolysis, therefore the amine-containing protein should be conjugated prior to the photoactivatable (aryl azide) reaction.
Should the coupling reaction be protected from light?
During the initial coupling procedure, the solutions should be protected from light to avoid decomposition of the phenyl azide functional group.
What makes Sulfo-SBED useful for investigation of protein interactions?
Sulfo-SBED allows one to transfer a biotin tag from an amine-containing protein to a second protein (reacted with the phenyl azide). The amine-containing protein can be removed by reduction of the disulfide in the Sulfo-SBED spacer arm. This leaves just the second biotinylated protein for detection.