Lipid bilayer condition abnormalities following Macrovipera lebetina obtusa snake envenomation.
Viper bites is an endemic public health problem in Armenia, even in the cities. Human envenomation is often characterized by clotting disorders, hypofibrinogenemia, and local tissue necrosis. In this original study, we assess some changes of cell membranes plastic properties (namely, its microviscosity, thickness, permeability) in a rat envenomation model using the biophysical approaches. We describe the interaction of Macrovipera lebetina obtusa (MLO) venom with giant unilamellar vesicles (GUVs) composed of the native phospholipid mixtures visualized through fluorescent microscopy. GUVs with a mean diameter of 30 μm have a minimum curvature and mimic cell membranes in this respect. The membrane fluorescence probe, ANS and pyrene, were used to assess the state of membrane and specifically mark the phospholipid domains. Independent of their lipid composition, GUVs were enlarged in size as venom-dependent lipid hydrolysis proceeded. Except of the visible morphological changes, ANS and pyrene also allows us to quantify the fluidity changes in the membrane by measuring of the fluorescence intensity. The presence of viper venom in GUVs media reveals a noticeable decreasing of membrane fluidity compare the control, while the binding of fluorophores with GUVs modified by venom lead to appearance of channel activity. These studies also emphasize the importance of a membrane surface curvature for its interaction with enzymatic components of venom.
Institute of Physiology, Orbely Str. 22, 0019 Yerevan, Armenia. taipan@ysu.am
Naira M
NM
Ayvazyan
Narine A
NA
Ghazaryan
D000818:Animals; D002458:Cell Fractionation; D004553:Electric Conductivity; D007273:Injections, Intramuscular; D007473:Ion Channels / Q000187:drug effects; D008051:Lipid Bilayers / Q000737:chemistry; D008297:Male; D008560:Membrane Fluidity / Q000187:drug effects; D008567:Membranes, Artificial; D008856:Microscopy, Fluorescence; D011485:Protein Binding; D051381:Rats; D012909:Snake Bites; D053835:Unilamellar Liposomes / Q000737:chemistry*; D014757:Viper Venoms / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D017819:Viperidae / Q000378:metabolism
D007473:Ion Channels; D008051:Lipid Bilayers; D008567:Membranes, Artificial; D053835:Unilamellar Liposomes; D014757:Viper Venoms