Non-Lethal Polypeptide Components in Cobra Venom

Abstract

Snakes from several genera (mostly from Naja genus) belonging to the Elapidae family are usually named cobras. The effect of cobra bites is mainly neurotoxic. This is explained by the presence of highly potent alpha-neurotoxin in their venoms. The other two highly toxic components of cobra venoms are cytotoxins and phospholipases A(2). These three types of toxins constitute a major part of cobra venom. They have attracted the attention of researchers for many years and have been very well studied and thoroughly described. However cobra venoms contain also many other less abundant components which possess very low toxicity or even are not toxic at all. These components, mostly proteins, belong to different structural and functional types, and the reason for their presence in the venom is not always evident. Some of them are known for many years (e.g., nerve growth factor and cobra venom factor); others (e.g., cysteine rich secretory proteins, CRISPs) were discovered only recently. There are non-lethal proteins with unique biological activities that can be used as biochemical tools, while others may be regarded as potential leads for drug design. This review is the first attempt to systemize the available data on non-lethal components of cobra venom.

Anti-angiogenic activities of snake venom CRISP isolated from Echis carinatus sochureki

“…Indeed, CRISP isolated from various venoms blocks L-type of calcium and cyclic nucleotide gated channels, that may harm the victims [16,17]. However, experimental treatment of mice and insects with these proteins yielded no toxic effects [18]. Our studies with an avian embryonic model confirmed the lack of toxicity of snake venom CRISP, since ES-CRISP in doses up to 40 μg was harmless to quail embryos, which are very sensitive to exogenous toxins.…”

“…The biological activity of snake venom CRISPs is still not fully understood; some were characterized as blockers of L-type calcium channels [16] and cyclic nucleotide gated channels [17]. Although ex vivo, CRISPs block rat arterial smooth muscle contraction [16], they appear to belong to the non-toxic components of snake venoms, because they have no toxic effects on mice or insect [18]. Recent studies showed that CRISP isolated from cobra venom, activates endothelial cells as inferred from the increased expression adhesion molecules (VCAM-1 and ICAM-1) and E-selectin [19].…”

Hemostatic and toxinological diversities in venom of Micrurus tener tener, Micrurus fulvius fulvius and Micrurus isozonus coral snakes

“…Several Elapidae snake venoms with neurotoxic activity, such as the cobras (Elapidae), also contain proteins that activate or inhibit the hemostatic system (Utkin and Osipov, 2007; Osipov et al, 2010). For instance, a metalloprotease enzyme capable of activating factor V was described in the venom of Naja naja oxiana (Gerads et al, 1992).…”

Azemiopsin from Azemiops feae Viper Venom, a Novel Polypeptide Ligand of Nicotinic Acetylcholine Receptor

“…Snake venoms are complex mixtures of peptides and proteins possessing different types of biological activity (1). Recent proteomic studies showed that, depending on the snake species, each venom may contain from several tens (2) to several hundred (3, 4) proteins.…”