Corrigendum to “Exploring and understanding the functional role, and biochemical and structural characteristics of an acidic phospholipase A2, AplTx-I, purified from Agkistrodon piscivorus leucostoma snake venom” [Toxicon 127 (2017) 22–36]

Abstract

Phospholipases A2(PLA2s) constitute a class of extensively studied toxins, isolated from snake venoms.Basic PLA2isoforms mediate various toxicological effects, while the acidic isoforms generally have higherenzymatic activities, but do not promote evident toxic effects. The functions of these acidic isoforms insnake venoms are still not completely understood and more studies are needed to characterize thebiological functions and diversification of acidic toxins in order to justify their abundant presence inthese secretions. Recently, Lomonte and collaborators demonstrated, in a proteomic and toxicologicalstudy, high concentrations of PLA2s in the venom ofAgkistrodon piscivorus leucostoma.We have, herein,purified and characterized an acidic PLA2from this snake venom, denominated AplTx-I, in order to betterunderstand its biochemical and structural characteristics, as well as its biological effects. AplTx-I waspurified using two chromatographic steps, in association with enzymatic and biological assays. The acidictoxin was found to be one of the most abundant proteins in the venom ofA. p. leucostoma;the proteinwas monomeric with a molecular mass of 13,885.8 Da, as identified by mass spectrometry ESI-TOF andelectrophoresis. The toxin has similar primary and tridimensional structures to those of other acidicPLA2s, a theoretical and experimental isoelectric point ofz5.12, and a calcium-dependent enzyme ac-tivity of 25.8985 nM/min/mg, with maximum values at 37 C and pH 8.0. Despite its high enzymaticactivity on synthetic substrate, AplTx-I did not induce high or significant myotoxic, coagulant, antico-agulant, edema, neuromuscular toxicity in mouse phrenic nerve-diaphragm preparations or antibacterialactivities. Interestingly, AplTx-I triggered a high and selective neuromuscular toxicity in chickbiventercervicispreparations. Thesefindings are relevant to provide a deeper understanding of the pharma-cology, role and diversification of acidic phospholipase A2isoforms in snake venoms.