Structure- and Substrate- Based Inhibitor Design for Clostridium botulinum Neurotoxin Serotype A*
Journal Article
·
· Journal of Biological Chemistry
The seven antigenically distinct serotypes of Clostridium botulinum neurotoxins cleave specific soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex proteins and block the release of neurotransmitters that cause flaccid paralysis and are considered potential bioweapons. Botulinum neurotoxin type A is the most potent among the clostridial neurotoxins, and to date there is no post-exposure therapeutic intervention available. To develop inhibitors leading to drug design, it is imperative that critical interactions between the enzyme and the substrate near the active site are known. Although enzyme-substrate interactions at exosites away from the active site are mapped in detail for botulinum neurotoxin type A, information about the active site interactions is lacking. Here, we present the crystal structures of botulinum neurotoxin type A catalytic domain in complex with four inhibitory substrate analog tetrapeptides, viz. RRGC, RRGL, RRGI, and RRGM at resolutions of 1.6-1.8 Angstroms . These structures show for the first time the interactions between the substrate and enzyme at the active site and delineate residues important for substrate stabilization and catalytic activity. We show that OH of Tyr366 and NH2 of Arg363 are hydrogen-bonded to carbonyl oxygens of P1 and P1' of the substrate analog and position it for catalytic activity. Most importantly, the nucleophilic water is replaced by the amino group of the N-terminal residue of the tetrapeptide. Furthermore, the S1' site is formed by Phe194, Thr215, Thr220, Asp370, and Arg363. The Ki of the best inhibitory tetrapeptide is 157 nm.
- Research Organization:
- Brookhaven National Laboratory (BNL) National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 959574
- Report Number(s):
- BNL--82560-2009-JA
- Journal Information:
- Journal of Biological Chemistry, Journal Name: Journal of Biological Chemistry Vol. 283; ISSN JBCHA3; ISSN 0021-9258
- Country of Publication:
- United States
- Language:
- English
Similar Records
Substrate Binding Mode and its Implication on Drug Design for Botulinum Neurotoxin A
Structural And Biochemical Studies of Botulinum Neurotoxin Serotype C1 Light Chain Protease: Implications for Dual Substrate Specificity
CRYSTAL STRUCTURE OF CLOSTRIDIUM BOTULINUM NEUROTOXIN SEROTYPE B.
Journal Article
·
Mon Dec 31 23:00:00 EST 2007
· PLoS Pathogens
·
OSTI ID:980578
Structural And Biochemical Studies of Botulinum Neurotoxin Serotype C1 Light Chain Protease: Implications for Dual Substrate Specificity
Journal Article
·
Mon Jun 01 00:00:00 EDT 2009
· Biochem. 46:10685,2007
·
OSTI ID:953998
CRYSTAL STRUCTURE OF CLOSTRIDIUM BOTULINUM NEUROTOXIN SEROTYPE B.
Book
·
Sun Nov 18 23:00:00 EST 2001
·
OSTI ID:789785