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

Abstract

The coral snake Micrurus tener tener (Mtt) from the Elapidae family inhabits the southwestern United States and produces severe cases of envenomations. Although the majority of Mtt venom components are neurotoxins and phospholipase A2s, this study demonstrated, by SDS-PAGE and molecular exclusion chromatography (MEC), that these venoms also contain high-molecular-weight proteins between 50 and 150 kDa that target the hemostatic system. The biological aspects of other Micrurus venoms were also studied, such as the LD50s of Micrurus isozonus (from 0.52 to 0.61 mg/kg). A pool from these venoms presented a LD50 of 0.57 mg/kg, Micrurus f. fulvius (Mff) and Mtt had LD50s of 0.32 and 0.78 mg/kg, respectively. These venoms contained fibrino(geno)lytic activity, they inhibited platelet aggregation, as well as factor Xa and/or plasmin-like activities. M. isozonus venoms from different Venezuelan geographical regions inhibited ADP-induced platelet aggregation (from 50 to 68%). Micrurus tener tener venom from the United States was the most active with a 95.2% inhibitory effect. This venom showed thrombin-like activity on fibrinogen and human plasma. Fractions of Mtt showed fibrino(geno)lytic activity and inhibition on plasmin amidolytic activity. Several fractions degraded the fibrinogen Aα chains, and fractions F2 and F7 completely degraded both fibrinogen Aα and Bβ chains. To our knowledge, this is the first report on thrombin-like and fibrino(geno)lytic activity and plasmin or factor Xa inhibitors described in Micrurus venoms. Further purification and characterization of these Micrurus venom components could be of therapeutic use in the treatment of hemostatic disorders.

Functional characterizations of venom phenotypes in the eastern diamondback rattlesnake (Crotalus adamanteus) and evidence for expression-driven divergence in toxic activities among populations

“…Identifying phenotypic variation is usually straightforward, but determining the functional significance of this variation relative to the ecology and evolution of a particular lineage can often be difficult (Gibbs and Mackessy, 2009). Snake venoms provide an ideal system for identifying functionally important phenotypic variation because venom variation is common (Chippaux et al, 1991; Daltry et al, 1996; Mackessy et al, 2003; Pung et al, 2005; Mackessy, 2008; Casewell et al, 2014), although not ubiquitous (Margres et al, 2015a), and venoms can be functionally characterized through simple assays and experimental tests (Huang and Perez, 1980; Bernheimer et al, 1987; da Silva and Aird, 2001; Sánchez et al, 2003; Kini, 2005; Sánchez et al, 2005; Bello et al, 2006; Calvete et al, 2007; Núñez et al, 2009; Salazar et al, 2009; Calvete et al, 2010; Suntravat et al, 2010; Biardi and Coss, 2011; Bohlen et al, 2011; Ciscotto et al, 2011; Salazar et al, 2011). …”

Clotting and fibrinogenolysis inhibition by essential oils from species of the Asteraceae family

“…Proteases (serine and metalloproteinases) are the principal enzymes responsible for these activities, being involved in the induction of necrosis and hemorrhage 2,8,10,11,12,13 . 13 .…”

Biological characterization of the Amazon coral Micrurus spixii snake venom: Isolation of a new neurotoxic phospholipase A2

“…This genus presents a greater variability of species in the areas surrounding the equator (Salazar et al, 2011). Micrurus spixii (Fig.…”