Abstract: Compositions and methods for characterization binding proteins are described that include use of a reporting construct that incorporates a bait region that interacts with the binding protein and a reporter that is susceptible to degradation in the reporter's local environment. Complex formation between the bait region and the binding protein provides protection of the susceptible reporter from degradation. Such a reporting construct can be utilized to identify cells expressing a binding protein when the susceptible reporter is susceptible to degradation in cytosol.

Abstract: Compositions for characterization of botulinum toxin (BoNT) are described that include a genetically modified cell that is transfected with an artificial construct comprising a nucleic acid sequence that encodes for a hybrid protein having (a) a reporter-containing portion chemically coupled to (b) a cleavage site and (c) a control fluorophore. The cleavage site interacts with a BoNT in a manner that cleaves the reporter-containing portion from remainder of the construct. The cleaved portion is destroyed or otherwise degraded by the local environment, and presence of BoNT is evidenced by reduction in signal from the reporter. The cleavage sequence is all or part of a SNARE protein, the cleavable reporter-containing portion is preferably Yellow Fluorescent Protein (YFP), Citrine, Venus, or a YPet protein and the control fluorophore is preferably CFP, mStrawberry, or a mCherry protein.

Abstract: Compositions for characterization of Botulinum toxin (BoNT) are described that include a genetically modified cell that is transfected with an artificial construct comprising a nucleic acid sequence that encodes for a hybrid protein having (a) a reporter-containing portion chemically coupled to (b) a cleavage site and (c) a control fluorophore. The cleavage site interacts with a BoNT in a manner that cleaves the reporter-containing portion from remainder of the construct. The cleaved portion is destroyed or otherwise degraded by the local environment, and presence of BoNT is evidenced by reduction in signal from the reporter. The cleavage sequence is all or part of a SNARE protein, the cleavable reporter-containing portion is preferably Yellow Fluorescent Protein (YFP), Citrine, Venus, or a YPet protein and the control fluorophore is preferably CFP, mStrawberry, or a mCherry protein.

Abstract: Compositions for characterization of Botulinum toxin (BoNT) are described that include a genetically modified cell that is transfected with an artificial construct comprising a nucleic acid sequence that encodes for a hybrid protein having (a) a reporter-containing portion chemically coupled to (b) a cleavage site and (c) a control fluorophore. The cleavage site interacts with a BoNT in a manner that cleaves the reporter-containing portion from remainder of the construct. The cleaved portion is destroyed or otherwise degraded by the local environment, and presence of BoNT is evidenced by reduction in signal from the reporter. The cleavage sequence is all or part of a SNARE protein, the cleavable reporter-containing portion is preferably Yellow Fluorescent Protein (YFP), Citrine, Venus, or a YPet protein and the control fluorophore is preferably CFP, mStrawberry, or a mCherry protein.

Abstract: Compositions for characterization of Botulinum toxin (BoNT) are described that include a genetically modified cell that is transfected with an artificial construct comprising a nucleic acid sequence that encodes for a hybrid protein having (a) a reporter-containing portion chemically coupled to (b) a cleavage site and (c) a control fluorophore. The cleavage site interacts with a BoNT in a manner that cleaves the reporter-containing portion from remainder of the construct. The cleaved portion is destroyed or otherwise degraded by the local environment, and presence of BoNT is evidenced by reduction in signal from the reporter. The cleavage sequence is all or part of a SNARE protein, the cleavable reporter-containing portion is preferably Yellow Fluorescent Protein (YFP), Citrine, Venus, or a YPet protein and the control fluorophore is preferably CFP, mStrawberry, or a mCherry protein.

Abstract: A composition includes an artificial construct having (a) a reporter-containing portion chemically coupled to (b) a cleavage site. The cleavage site interacts with an investigational substance in a manner that cleaves the reporter-containing portion from a remainder of the construct. The cleaved portion is destroyed or otherwise degraded by the local environment, and presence of an investigational substance is evidenced by reduction in signal from the reporter. The investigational substance is preferably a Botulinum toxin (BoTN), and the cleavage sequence is all or part of a SNARE protein. The cleavable reporter-containing portion is preferably Yellow Fluorescent Protein (YFP), Citrine, Venus, or a YPet protein.

Abstract: A composition includes an artificial construct having (a) a reporter-containing portion chemically coupled to (b) a cleavage site. The cleavage site interacts with an investigational substance in a manner that cleaves the reporter-containing portion from a remainder of the construct. The cleaved portion is destroyed or otherwise degraded by the local environment, and presence of an investigational substance is evidenced by reduction in signal from the reporter. The investigational substance is preferably a Botulinum toxin (BoTN), and the cleavage sequence is all or part of a SNARE protein. The cleavable reporter-containing portion is preferably Yellow Fluorescent Protein (YFP), Citrine, Venus, or a YPet protein.