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.