Dendrotoxins are a group of proteins found in the venom of the black mamba (Dendroaspis polylepis polylepis) and the eastern green mamba (Dendroaspis angusticeps). They belong to the bpti (bovine pancreatic trypsin inhibitor)/kunitz family of inhibitors. They also aid in the release of acetylcholine from presynaptic membranes of cholinergic synapses. Dendrotoxin K inhibits trypsin slightly, but it fails to inhibit chymotrypsin at all. However, dendrotoxin K is a selective blocker of voltage-gated potassium channels.
Dendrotoxin K is a 57 amino-acid residue long protein that contains three disulfide bonds: Cys5-Cys55, Cys14-Cys38, and Cys30-Cys51. This picture is colored by secondary structure: Alpha helices=Blue, beta sheets=yellow. The disulfide bonds are shown in white.

• Keywords: Venom, Serine Protease Inhibitor, Neurotoxin, Potassium Channel Inhibitor
• View this protein's PDB entry as 1DTK
• View this protein's SwissProt entry as IVBK_DENPO
• References:
  • K.D. Berndt, P. Guntert, K. Wuthrich
    Nuclear Magnetic Resonance Solution Structure of Dendrotoxin K From the Venom of Dendroaspis Polylepis Polylepis.
    J Mol Biol 234:735 (1993)
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  • R.M. Keller, R. Baumann, E-H. Hunziker-Kwik, F.J. Joubert, K. Wuthrich
    Assignment of the 1H Nuclear Magnetic Resonance Spectrum of the Trypsin Inhibitor Homologue K From Dendroaspis Polylepis Polylepis: Two-Dimensional Nuclear Magnetic Resonance at 360 and 500 MHz.
    J Mol. Biol. 163:623 (1983)
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  • M. Hollecker, T.E. Creighton
    Evolutionary Conservation and Variation of Protein Folding Pathways: Two Protease Inhibitor Homologues From Black Mamba Venom.
    J. Mol. Biol. 168:409 (1983)
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  • D.J. Strydom
    Protease Inhibitors as Snake Venom Toxins
    Nature New Biol. 247:88 (1973)
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