Purification and Characterization of Nk-3FTx: A Three Finger Toxin from the Venom of North East Indian Monocled Cobra

Proteome of monocled cobra (Naja kaouthia) venom and potent anti breast cancer peptide from trypsin hydrolyzate of the venom protein

Anticancer peptide is one of the target in the development of new anticancer drug. Bioactive peptide can be originated from isolated free peptide or produced by hydrolysis of protein. Protein is the main component of Naja kaouthia venom, and due to the toxicity of the venom, it can be assessed as the source of anticancer peptides. This study aims to characterize the venom protein and to identify peptides from the snake venom of N. kaouthia as anticancer. Proteome analysis was employed trypsin hydrolysis of N. kaouthia venom protein completed with HRMS analysis protein database query. Preparative tryptic hydrolysis of the protein followed by reverse-phased fractionation and anti breast cancer activity testing were performed to identify the potent anticancer from the hydrolysate. Proteomic analysis by high-resolution mass spectrometry revealed that there are 20 enzymatic and non-enzymatic proteins in N. kaouthia venom. The 25% methanol peptide fraction had the most active anticancer activity against MCF-7 breast cancer cells and showed promising selectivity (selectivity index = 12.87). Amino acid sequences of eight peptides were identified as potentially providing anticancer compounds. Molecular docking analysis showed that WWSDHR and IWDTIEK peptides gave specific interactions and better binding affinity energy with values of -9.3 kcal/mol and -8.4 kcal/mol, respectively. This study revealed peptides from the snake venom of N. kaouthia became a potent source of new anticancer agents.

The secretory phenotypes of envenomed cells: Insights into venom cytotoxicity

Snake envenomation is listed as Category A Neglected Tropical Diseases (NTD) by World Health Organization, indicates a severe public health problem. The global figures for envenomation cases are estimated to be more than 1.8 million annually. Even if the affected victims survive the envenomation, they might suffer from permanent morbidity due to local envenomation. One of the most prominent local envenomation is dermonecrosis. Dermonecrosis is a pathophysiological outcome of envenomation that often causes disability in the victims due to surgical amputations, deformities, contracture, and chronic ulceration. The key venom toxins associated with this local symptom are mainly attributed to substantial levels of enzymatic and non-enzymatic toxins as well as their possible synergistic actions. Despite so, the severity of the local tissue damage is based on macroscopic observation of the bite areas. Furthermore, limited knowledge is known about the key biomarkers involved in the pathogenesis of dermonecrosis. The current immunotherapy with antivenom is also ineffective against dermonecrosis. These local effects eventually end up as sequelae. There is also a global shortage of toxins-targeted therapeutics attributed to inadequate knowledge of the actual molecular mechanisms of cytotoxicity. This chapter discusses the characterization of secretory phenotypes of dermonecrosis as an advanced tool to indicate its severity and pathogenesis in envenomation. Altogether, the secretory phenotypes of envenomed cells and tissues represent the precise characteristics of dermonecrosis caused by venom toxins.

Effects of 3FTx Protein Fraction from Naja ashei Venom on the Model and Native Membranes: Recognition and Implications for the Mechanisms of Toxicity

Three-finger toxins are naturally occurring proteins in Elapidae snake venoms. Nowadays, they are gaining popularity because of their therapeutic potential. On the other hand, these proteins may cause undesirable reactions inside the body′s cells. A full assessment of the safety of Naja ashei venom components for human cell application is still unknown. The aim of the study was to determine the effect of the exogenous application of three-finger toxins on the cells of monocytes (U-937) and promyelocytes (HL-60), with particular emphasis on the modification of their membranes under the influence of various doses of 3FTx protein fraction (0–120 ng/mL). The fraction exhibiting the highest proportion of 3FTx proteins after size exclusion chromatography (SEC) separation was used in the experiments. The structural response of cell membranes was described on the basis of single-component and multi-component Langmuir monolayers that mimicked the native membranes. The results show that the mechanism of protein–lipid interactions depends on both the presence of lipid polar parts (especially zwitterionic type of lipids) and the degree of membrane saturation (the greatest-for unsaturated lipids). The biochemical indicators reflecting the tested cells (MDA, LDH, cell survival, induction of inflammation, LD50) proved the results that were obtained for the model.

A comparative analysis of the proteomes and biological activities of the venoms from two sea snakes, Hydrophis curtus and Hydrophis cyanocinctus, from Hainan, China

We characterized and compared the venom protein profiles of Hydrophis curtus (synonyms: Lapemis hardwickii, Lapemis curtus and Hydrophis hardwickii) and Hydrophis cyanocinctus, the two representatives of medically important venomous sea snakes in Chinese waters using proteomic approaches. A total of 47 and 38 putative toxins were identified in H. curtus venom (HcuV) and H. cyanocinctus venom (HcyV), respectively, and these toxins could be grouped into 15 functional categories, mainly proteinases, phospholipases, three-finger toxins (3FTxs), lectins, protease inhibitors, ion channel inhibitors, cysteine-rich venom proteins (CRVPs) and snake venom metalloproteases (SVMPs). The constituent ratio of each toxin category varied between HcuV and HcyV with 3FTx (54% in HcuV/69% in HcyV) and PLA2 (38% in HcuV/22% in HcyV) unanimously ranked as the top two most abundant families. Both HcuV and HcyV exhibited relatively high lethality (LD₅₀ values in mice of 0.34 μg/g and 0.24 μg/g, respectively), specific PLA2 activity and hemolytic activity. On the basis of several previous reports of HcuV and HcyV collected from other areas, these findings greatly expand our understanding of geographical variation and interspecies diversity of the two sea snake venoms and can provide a scientific basis for the development of specific sea snake antivenom in the future.

Snake Venom Peptides: Tools of Biodiscovery

Nature endowed snakes with a lethal secretion known as venom, which has been fine-tuned over millions of years of evolution. Snakes utilize venom to subdue their prey and to survive in their natural habitat. Venom is known to be a very poisonous mixture, consisting of a variety of molecules, such as carbohydrates, nucleosides, amino acids, lipids, proteins and peptides. Proteins and peptides are the major constituents of the dry weight of snake venoms and are of main interest for scientific investigations as well as for various pharmacological applications. Snake venoms contain enzymatic and non-enzymatic proteins and peptides, which are grouped into different families based on their structure and function. Members of a single family display significant similarities in their primary, secondary and tertiary structures, but in many cases have distinct pharmacological functions and different bioactivities. The functional specificity of peptides belonging to the same family can be attributed to subtle variations in their amino acid sequences. Currently, complementary tools and techniques are utilized to isolate and characterize the peptides, and study their potential applications as molecular probes, and possible templates for drug discovery and design investigations.

Electro-Physiology of Coupling Model and Its Impact on Naja Kaouthia Venom Treated Sciatic Nerves of Toad

Demyelination in peripheral nerves causes dysfunction of slowing down and stoppage of nerve impulses causing many neurological diseases, such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. This paper aims to develop a recovery model having interaction of a demyelinated nerve with a normal myelinated nerve. We validated the model by coupling between peripheral nerve of toad (demyelinated with Naja kaouthia venom) and a normal nerve of toad. An increase in both nerve conduction velocity as well as compound action potential amplitude is observed in the repetition of the experiments indicating gradual recovery of the patients. The significance behind this work is to suppress the malfunctioning of the demyelinated nerve by the normal electro-physiological activity of the normal nerve for speedy recovery using coupling model. The recovery model will be used in the treatment of neurological disorders with the influence of normal neuro physiological properties of a normal adjacent nerve.

Quantifying Demyelination in NK venom treated nerve using its electric circuit model

Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination.