A Scorpion Dervied Protein to Prevent Vesicle FusionCase # 0808

Technology Contact

A. Carlyle Rogers, PhD
Phone: 252-737-1648


 Fletcher Technology Description




The American Society for Aesthetic Plastic Surgery reports that over 2.4 million Botox injections were given in the U.S. in 2008. At an average cost of $443 per injection, Botox generates revenue of over $1 billion a year. Botox has been a commercial success, but producing Botox is work intensive and costly, limiting profitability.


Dr. Paul Fletcher and his co-investigators from the Department of Microbiology and Immunology at the Brody School of Medicine at East Carolina University and the NIH have discovered a novel protein that has similar functionality to Botox®. Antarease is a 25.5 kDa zinc metalloprotease that is derived from the venom of the Brazilian Scorpion, Tityus serrulatus. The protein cleaves the synaptobrevin, vesicle-associated membrane protein 2, 3, 7 and 8 (VAMP2, 3, 7 and 8), which is found on the outside of vesicles. Cleavage of VAMP prevents the fusion of vesicles with membranes, leading to a reduction in the release of  molecules . In addition to VAMP, the protease also cleaves SNAP25.


  • Effective Cleaving and Rapid Onset Compared to Botulinum Toxin 
  • Smaller Size and Ease of Production Allows For widespread molecular biology use (i.e. Antibody Conjugates)


  • Cosmetic Applications 
  • Blepharospasms 
  • Migraines 
  • Cystic Fibrosis 
  • Inflammation 
  • Diabetes 
  • Research Investigation

Selected Publications

Fletcher et al., "Vesicle-associated membrane protein (VAMP) cleavage by a new metalloprotease from the Brazilian scorpion Tityus serrulatus.." J. Biol. Chem. Mar 5;285(10):7405-16. 2010 PMID: 20026600

Fletcher et al "Isolation and Pharmacological Characterization of Four Novel Na+ Channel-Blocking Toxins from the Scorpion Centruroides noxius Hoffman." J. Biochem. 116:1383-1391 1994 PMID: 7706233


Inventor Profile

Dr. Paul Fletcher is an associate professor in the Department of Microbiology and Immunology at East Carolina University Brody School of Medicine.His research interests include structural determination and functional characteristics of bioactive proteins in scorpion venom. Dr. Fletcher earned his Ph.D. from Vanderbilt University, his M.S. from the University of North Carolina at Greensboro and his BS from Virginia Polytechnic Institute. Also contributing to this technology are Maryann Fletcher from the Brody School of Medicine and Brian Martin from the National Institute of Mental Health (NIMH). Click to Learn More...