Abstract
Kunitz-type proteins that interfere with neuronal transmission have been thus far exclusively detected in venoms of elapid snakes. Here, we report for the first time that such proteins are also present in the venom of a viperid snake. From the venom of the nose-horned viper (Vipera ammodytes ammodytes; Vaa), we isolated Kunitz-type chymotrypsin inhibitors (VaaChi) and demonstrated that these molecules also significantly increase the amplitudes of an indirectly evoked simple muscle contraction of the mouse hemidiaphragm, the end-plate potential and the miniature end-plate potential. By facilitating neuromuscular transmission, these proteins resemble structurally homologous dendrotoxins from mamba (Dendroaspis spp.) venoms, which are blockers of voltage-dependent K+ channels at the presynaptic site of the neuromuscular junction. What is the mechanism behind facilitation of neuromuscular transmission by VaaChi has not been established yet, however, blocking of K+ channels does not seem to be the most probable option.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
