Structural highlights
Function
[MIT1_DENPO] Potently contracts gastrointestinal (GI) smooth muscle. The receptor for this toxin is present both in the CNS and in the smooth muscle and may be a potassium channel.[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The solution structure of mamba intestinal toxin 1 (MIT1), isolated from Dendroaspis polylepis polylepis venom, has been determined. This molecule is a cysteine-rich polypeptide exhibiting no recognised family membership. Resistance to MIT1 to classical specific endoproteases produced contradictory NMR and biochemical information concerning disulphide-bridge topology. We have used distance restraints allowing ambiguous partners between S atoms in combination with NMR-derived structural information, to correctly determine the disulphide-bridge topology. The resultant solution structure of MIT1, determined to a resolution of 0.5 A, reveals an unexpectedly similar global fold with respect to colipase, a protein involved in fatty acid digestion. Colipase exhibits an analogous resistance to endoprotease activity, indicating for the first time the possible topological origins of this biochemical property. The biochemical and structural homology permitted us to propose a mechanically related digestive function for MIT1 and provides novel information concerning snake venom protein evolution.
A structural homologue of colipase in black mamba venom revealed by NMR floating disulphide bridge analysis.,Boisbouvier J, Albrand JP, Blackledge M, Jaquinod M, Schweitz H, Lazdunski M, Marion D J Mol Biol. 1998;283(1):205-19. PMID:9761684[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Schweitz H, Pacaud P, Diochot S, Moinier D, Lazdunski M. MIT(1), a black mamba toxin with a new and highly potent activity on intestinal contraction. FEBS Lett. 1999 Nov 19;461(3):183-8. PMID:10567694
- ↑ Boisbouvier J, Albrand JP, Blackledge M, Jaquinod M, Schweitz H, Lazdunski M, Marion D. A structural homologue of colipase in black mamba venom revealed by NMR floating disulphide bridge analysis. J Mol Biol. 1998;283(1):205-19. PMID:9761684 doi:10.1006/jmbi.1998.2057
