Toxins from Venomous Animals: Gene Cloning, Protein Expression and Biotechnological Applications

Abstract

and binding site on different channels or channel subtypes. The venom is constituted by mucopolysaccharides, hyaluronidases, phospholipases, serotonins, histamines, enzyme inhibitors, antimicrobials and proteins namely neurotoxic peptides. Scorpion peptides presents specificity and high affinity and have been used as pharmacological tools to characterize various receptor proteins involved in normal ion channel functionating, as abnormal channel functionating in cases of diseases. The venoms can be characterized by identification of peptide toxins analysis of the structure of the toxins and also have proven to be among the most and selective antagonists available for voltage-gated channels permeable to K + , Na + , and Ca 2+. The neurotoxic peptides and small proteins lead to dysfunction and provoke pathophysiological actions, such as membrane destabilization, blocking of the central, and peripheral nervous systems or alteration of smooth or skeletal muscle activity [5-8]. Spider venoms are complex mixtures of biologically active compounds of different chemical nature, from salts to peptides and proteins. Specificity of action of some spider toxins is unique along with high toxicity for insects, they can be absolutely harmless for members of other taxons, and this could be essential for investigation of insecticides. Several spider toxins have been identified and characterized biochemically. These include mainly ribonucleotide phosphohydrolase, hyaluronidases, serine proteases, metalloproteases, insecticidal peptides and phospholipases D [9-10]. Venoms from toads and frogs have been extensively isolated and characterized showing molecules endowed with antimicrobial and/or cytotoxic activities [11]. Studies involving the molecular repertoire of the venom of bees and wasps have revealed the partial isolation, characterization and biological activity assays of histamines, dopamines, kinins, phospholipases and hyaluronidases. The venom of caterpillars has been partially characterized and contains mainly ester hydrolases, phospholipases and proteases [12]. The purpose of this chapter is to present the main toxins isolated and characterized from the venom of venomous animals, focusing on their biotechnological and pharmacological applications. 2. Biotechnological and pharmacological applications of snake venom toxins While the initial interest in snake venom research was to understand how to combat effects of snakebites in humans and to elucidate toxins mechanisms, snake venoms have become a fertile area for the discovery of novel products with biotechnological and/or pharmacological applications [13-14]. Since then, many different products have been developed based on purified toxins from snake venoms, as well recent studies have been showing new potential molecules for a variety of applications [15]. 2.1. Toxins acting on cardiovascular system Increase in blood pressure is often a transient physiological response to stressful stimuli, which allows the body to react to dangers or to promptly increase activity. However,...

Potential Biotechnological Applications of Venoms from the Viperidae Family in Central America for Thrombosis

“…Venoms are stored and synthesized in specialized glands and are released for defense, immobilization, and prey capture [ 103 , 104 ]. The protein composition of these venoms can vary qualitatively and quantitatively between species depending on region, climate, and different ontogenetic stages (developmental stages from birth to adulthood) [ 103 , 105 ]. Venomous secretions can produce harmful effects and even death of victims affected by bites [ 104 , 106 ].…”