Venom from Bothrops lanceolatus, a Snake Species Native to Martinique, Potently Activates the Complement System

Figure 3

Cleavage of purified C3, C4, and C5 by B. lanceolatus venom. Samples (2 μg) of purified Complement components C3 (a), C4 (b), and C5 (c) were incubated in PBS with B. lanceolatus venom (2 μg) for 30 min at 37°C. The cleavage was visualized by electrophoretic separation (10% acrylamide SDS-PAGE) under reducing conditions, followed by silver staining. (d) The functional activity of the venom-treated C5 fragments was assessed via measuring calcium influx in Fluo-4-AM-labelled leukocytes (5 × 10⁶ cells/mL). Purified C5a (2.4 ng/mL) and samples of C5 or venom incubated with saline were used as positive and negative controls, respectively. Cells were allowed to equilibrate for 60 sec before stimulation (arrow).

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