FRET Peptides, Native Substrates & Receptors The potent toxicity of both the botulinum neurotoxins and anthrax lethal toxin is due to a zinc-dependent proteolytic activity associated with the toxins. Measurement of this enzymatic activity provides for both a potentially sensitive and direct means for detection of the toxin, and a method for identifying potential toxin inhibitors using high throughput screening. A highly efficient approach for monitoring enzymatic activity is based on the use of fluorescence resonance energy transfer (FRET) substrates. These fluorogenic peptides contain a donor fluorescent group at one end and a suitable chromogenic acceptor group at the other. The fluorescence is quenched initially by intramolecular energy transfer between the donor/acceptor pair. Cleavage of the FRET substrate by the appropriate enzyme releases the fluorophore and full fluorescence is restored. The increase in fluorescence intensity is directly proportional to the amount of enzyme present. Enzymatic activity can be monitored continuously by recording the increase in fluorescence intensity with time. The change in the relative fluorescence units (RFU) as cleavage occurs can be converted to nmoles of cleaved substrate from a standard curve generated using a Calibration Peptide which is the cleaved substrate containing only the N-terminally attached fluorophore. For Botulinum neurotoxin type A, a Control FRET peptide substrate that is not cleaved by the neurotoxin but contains all remaining non-specific sites in the sequence can be used to screen background cleavage of the substrate that can occur in complex matrices. There are seven immunologically distinct botulinum neurotoxins, designated types A-G. Each neurotoxin toxin cleaves one of two target proteins critical for synaptic vesicle fusion to the plasma membrane and neurotransmitter release, either SNAP-25 or Synaptobrevin. The latter is also called VAMP-2. Types A, C and E specifically bind and selectively cleave SNAP-25 while types B, D, F and G cleave Synaptobrevin. Type C also cleaves Syntaxin. The enzymatic activity of these toxins can also be measured using the appropriate native substrate and monitoring the generation of the cleaved product on SDS-PAGE gel electrophoresis. The synaptic vesicle glycoprotein 2c (SV2c) has been shown to be the protein receptor for Botulinum neurotoxin, Type A (BoNT/A) and the luminal domain loop is the specific location of BoNT/A binding. This 124 amino acid domain of SV2c is available as a GST fusion protein. Our Citations include information referencing the use of FRET peptides in research. Our Support Portal provides technical information on our FRET peptides. Visit our blog to learn more about List Labs' products, services, and research. Calibration Fluorophore for VAMPtide® 540 Substrate
for C. botulinum Type B Neurotoxin Calibration Fluorophore for VAMPtide® 540 Substrate for C. botulinum Type B Neurotoxin #549 Control Peptide for SNAPtide® 520 Substrate
for C. botulinum Type A Neurotoxin Control Peptide for SNAPtide® 520 Substrate for C. botulinum Type A Neurotoxin #525 Control Peptide for SNAPtide® 521
for C. botulinum Type A Neurotoxin Control Peptide for SNAPtide® 521 for C. botulinum Type A Neurotoxin #526 GST Synaptobrevin-2 Protein Substrate
for C. botulinum Types B, D, and F GST Synaptobrevin-2 Protein Substrate for C. botulinum Types B, D, and F #510A MAPKKide® Peptide Substrate (DABCYL/FITC)
for Anthrax Lethal Factor MAPKKide® Peptide Substrate (DABCYL/FITC) for Anthrax Lethal Factor #531 MAPKKide® Peptide Substrate (o-Abz/Dnp)
for Anthrax Lethal Factor MAPKKide® Peptide Substrate (o-Abz/Dnp) for Anthrax Lethal Factor #530 MAPKKide® Plus (AMC) Specific Substrate
for Anthrax Lethal Factor MAPKKide® Plus (AMC) Specific Substrate for Anthrax Lethal Factor #532 Receptor forClostridium botulinumType A Neurotoxin, GST-SV2c luminal domain Receptor forClostridium botulinumType A Neurotoxin, GST-SV2c luminal domain #690B SNAP Etide® Peptide Substrate (o-Abz/Dnp)
for C. botulinum Type E Neurotoxin SNAP Etide® Peptide Substrate (o-Abz/Dnp) for C. botulinum Type E Neurotoxin #550 SNAP-25 Recombinant Protein Substrate
for C. botulinum Types A and E Neurotoxin SNAP-25 Recombinant Protein Substrate for C. botulinum Types A and E Neurotoxin #500A SNAPtide® Peptide Substrate (FITC/DABCYL)
for C. botulinum Type A Neurotoxin SNAPtide® Peptide Substrate (FITC/DABCYL) for C. botulinum Type A Neurotoxin #521 SNAPtide® Peptide Substrate (o-Abz/Dnp)
for C. botulinum Type A Neurotoxin SNAPtide® Peptide Substrate (o-Abz/Dnp) for C. botulinum Type A Neurotoxin #520 SNAPtide® Peptide Substrate flP6(DABCYL/5-IAF)
for C. botulinum Type A Neurotoxin SNAPtide® Peptide Substrate flP6(DABCYL/5-IAF) for C. botulinum Type A Neurotoxin #523 SYNTAXtide® (o-Abz/Dnp) Peptide Substrate
for C. botulinum Type C Neurotoxin SYNTAXtide® (o-Abz/Dnp) Peptide Substrate for C. botulinum Type C Neurotoxin #560 Unquenched Calibration Peptide for MAPKKide® 530
for Anthrax Lethal Factor Unquenched Calibration Peptide for MAPKKide® 530 for Anthrax Lethal Factor #539 Unquenched Calibration Peptide for SNAPtide® 520 Substrate for C. botulinum Type A Neurotoxin Unquenched Calibration Peptide for SNAPtide® 520 Substrate for C. botulinum Type A Neurotoxin #529 Unquenched Calibration Peptide for SNAPtide® 521 Substrate for C. botulinum Type A Neurotoxin Unquenched Calibration Peptide for SNAPtide® 521 Substrate for C. botulinum Type A Neurotoxin #528 VAMPtide® (Pya/Nop) Peptide Substrate
for Botulinum Neurotoxin Type B VAMPtide® (Pya/Nop) Peptide Substrate for Botulinum Neurotoxin Type B #542 VAMPtide® Peptide Substrate (FITC/DABCYL) Substrate
for C. botulinum Type B Neurotoxin VAMPtide® Peptide Substrate (FITC/DABCYL) Substrate for C. botulinum Type B Neurotoxin #541 VAMPtide® Peptide Substrate (o-Abz/Dnp) Substrate
for C. botulinum Type B Neurotoxin VAMPtide® Peptide Substrate (o-Abz/Dnp) Substrate for C. botulinum Type B Neurotoxin #540