J Venom Res (2020), Vol 10, in press
Published online: 06 July 2020
Elena V Kryukova 1, Catherine A Vulfius 2, Rustam H Ziganshin 1, Tatyana V Andreeva 1, Vladislav G Starkov 1, Victor I Tsetlin 1, Yuri N Utkin 1*
1 Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow 117997, Russia
2 Institute of Cell Biophysics Russian Academy of Sciences, 3 Institutskaya Street, Pushchino Moscow region, 142290, Russia
Received: 30 April 2020 | Revised: 02 July 2020 | Accepted: 06 July 2020
© Copyright The Author(s). This is an open access article, published under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0). This license permits non-commercial use, distribution and reproduction of this article, provided the original work is appropriately acknowledged, with correct citation details.
Venoms of viperid snakes affect mostly hemostasis while C-type lectin-like proteins (CTLPs), one of the main components of viperid venoms, act as anticoagulants, procoagulants, or agonists/antagonists of platelet activation. However, we have shown earlier that CTLPs from the saw-scaled viper Echis multisquamatus, called emunarecins EM1 and EM2, were able to inhibit nicotinic acetylcholine receptors (nAChRs) in neurons of a pond snail (Lymnaea stagnalis). Here we analysed the structure of the emunarecins by mass spectrometry and report that EM1 and EM2 inhibit fluorescent α-bungarotoxin binding to both muscle-type nAChRs from Torpedo californica and human neuronal α7 nAChRs. EM1 at 23µM and EM2 at 9µM almost completely prevented fluorecsent α-bungarotoxin binding to muscle-type nAChRs. Interaction with human neuronal α7 nAChR was weaker; EM1 at the concentration of 23µM blocked the α-bungarotoxin binding only by about 40% and EM2 at 9µM by about 20%. The efficiency of the EM2 interaction with nAChRs was comparable to that of a non-conventional toxin, WTX, from Naja kaouthia cobra venom. Together with the data obtained earlier, these results show that CTLPs may represent new nAChR ligands.
KEYWORDS: α-bungarotoxin, C-type lectin-like protein, nicotinic acetylcholine receptor, saw-scaled viper, snake, venom