Assays for detecting modified compounds

摘要

Provided are methods and compositions which are useful for separating, isolating, detecting, and quantifying compounds of interest which have been modified chemically, enzymatically or catalytically from other compounds which have not been so modified. The modifications may take the form of functional groups which are gained, lost or retained by the compounds of interest.

主权项

1. A reagent for determining the presence of an enzyme that adds or removes a charged functional group to an uncharged moiety on a substrate or quantifying the activity of said enzyme in a sample, the reagent comprising:
the substrate to which a first member and a second member of an energy transfer pair are covalently bound at a distance such that a FRET interaction does not occur unless the charged functional group is present, wherein the second member of the energy transfer pair has a charge opposite to the charge of the functional group, and wherein the presence of the charged functional group on the substrate causes noncovalent binding of the second member of the energy transfer pair to the charged functional group, bringing the first member and the second member of the energy transfer pair close enough so that a FRET interaction occurs.