ABSTRACT
Snake venoms are complex mixtures of pharmacologically active proteins and polypeptides, and they often contain over one hundred proteins, both enzymatic and nonenzymatic. However, these toxins belong to a very small number of superfamilies of proteins. One such family of nonenzymatic proteins is the three-nger toxin family. All three-nger toxins share a common structure of three β-stranded loops extending from a central core. However, they bind to different receptors/acceptors and exhibit a wide variety of biological effects. Thus, the structure-function relationships of this group of toxins are complicated and challenging to elucidate. Based on their biological activity, three-nger toxins can be classied into different categories. This chapter deals with the overall functions and structure-function relationships of each of the different categories of three-nger toxins.
