Bothrops diporus, previously considered a subspecies of the B. neuwiedi complex, is a medically relevant viperid in Northeastern Argentina. The
venom of this species causes local tissue damage characterized by myonecrosis,
hemorrhage, blistering, and
edema. In the present study, two basic
phospholipases A2 (PLA2-I and PLA2-II) were isolated from this
venom, and their pathological effects upon murine skeletal muscle and myogenic cells in culture were analyzed. Partial
amino acid sequencing showed that PLA2-I and
PLA2-II are Asp49 and Lys49 PLA2s, respectively. In agreement with this, PLA2-I showed PLA2 activity, whereas
PLA2-II did not. Functional assays revealed differences in their
myotoxicity, cytotoxicity, and anti-adhesion activity, and in the ability to inhibit cell migration, all of which were greater for the Lys49 variant. Native electrophoresis showed that PLA2-I was less basic than
PLA2-II. The two
proteins act synergistically to affect the integrity of C2C12 myogenic cells, providing a further example of the concerted action of coexisting
snake venom components. PLA2-I and
PLA2-II, together with additional basic PLA2s revealed by RP-HPLC, probably play an important role in myonecrosis after envenomation by B. diporus.