Synthesis, characterization and development of a high-throughput methodology for the discovery of botulinum neurotoxin a inhibitors.
Botulinum neurotoxins (BoNTs), etiological agents of the deadly food poisoning disease botulism, are the most toxic proteins currently known. Although only a few hundred cases of botulism are reported in the United States annually, there is growing interest in BoNTs attributable to their potential use as biological warfare agents. Neurotoxicity results from cleavage of the soluble NSF-attachment protein receptor complex proteins of the presynaptic vesicles by the BoNT light chain subunit, a Zn endopeptidase. Few effective inhibitors of BoNT/A LC (light chain) activity are known, and the discovery process is hampered by the lack of an efficient high-throughput assay for screening compound libraries. To alleviate this bottleneck, we have synthesized the peptide SNAPtide and have developed a robust assay for the high-throughput evaluation of BoNT/A LC inhibitors. Key aspects for the development of this optimized assay include the addition of a series of detergents, cosolvents, and salts, including 0.01% w/v Tween 20 to increase BoNT/A LC catalysis, stability, and ease of small molecule screening. To evaluate the effectiveness of the assay, a series of hydroxamate-based small molecules were synthesized and examined with BoNT/A LC. The methodology described is superior to other assays reported to date for the high-throughput identification of BoNT/A inhibitors.
Boldt
Grant E
GE
Department of Chemistry, The Skaggs Institute for Chemical Biology, and Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Kennedy
Jack P
JP
Hixon
Mark S
MS
McAllister
Laura A
LA
Barbieri
Joseph T
JT
Tzipori
Saul
S
Janda
Kim D
KD
D019274:Botulinum Toxins, Type A / Q000037:antagonists & inhibitors*; D002384:Catalysis; D002619:Chemical Warfare Agents / Q000633:toxicity; D003902:Detergents / Q000737:chemistry; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors; D009465:Neuromuscular Agents / Q000633:toxicity; D011480:Protease Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D050600:SNARE Proteins / Q000138:chemical synthesis* / Q000494:pharmacology; D012492:Salts / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D020058:Styrene / Q000737:chemistry; D013997:Time Factors
D002619:Chemical Warfare Agents; D003902:Detergents; D009465:Neuromuscular Agents; D011480:Protease Inhibitors; D050600:SNARE Proteins; D012492:Salts; D012997:Solvents; D020058:Styrene; D008666:Metalloendopeptidases; C022510:thimet oligopeptidase; D019274:Botulinum Toxins, Type A