Phospholipases A2 (PLA2 ) from snake venom are enzymes with highly variety of biological effects, due to their different isoforms and some may be myotoxins. This research aimed was to purify, characterize and evaluate the myotoxic activity of an isoform of acid PLA2 (BaPer-PLA2a). For purification, in DEAE Sephadex-A50, Sephadex-G75 and an automated medium pressure system-NGC were used. BaPer-PLA2a had a specific activity of 34.1 U/ mg and a MW of ~ 14.5 kDa by SDS-PAGE, non-reducing conditions. From venom were obtained total RNA, to synthesis of cDNA and an amplified of ~ 480 bp. A mature protein of 124 amino acids was deduced from the cDNA sequence with a pI (4.41), being an acidic isoform, likewise presented primary structure with conserved regions and residues His48, Asp49 and Tyr52 identified in the catalytic center. Additionally, the structural theoretical model has an identity gre...