Cloning and Identification of a Complete cDNA Coding for a Bactericidal and Antitumoral Acidic Phospholipase A2 from Bothrops jararacussu Venom

Abstract

In order to better understand the function of acidic phospholipases A2 (PLA2s) from snake venoms, expressed sequence tags (ESTs) that code for acidic PLA2s were isolated from a cDNA library prepared from the poly(A)+ RNA of venomous glands of Bothrops jararacussu. The complete nucleotide sequence (366 bp), named BOJU-III, encodes the BthA-I-PLA2 precursor, which includes a signal peptide and the mature protein with 16 and 122 amino acid residues, respectively. Multiple comparison of both the nucleotide and respective deduced amino acid sequence with EST and protein sequences from databases revealed that the full-length cDNA identified (BOJU III--AY145836) is related to an acidic PLA2 sharing similarity, within the range 55-81%, with acidic phospholipases from snake venoms. Moreover, phylogenetic analysis of amino acid sequences of acidic PLA2s from several pit viper genera showed close evolutionary relationships among acidic PLA2s from Bothrops, Crotalus, and Trimeresurus. The molecular modeling showed structural similarity with other dimeric class II PLA2s from snake venoms. The native protein BthA-I-PLA2, a nontoxic acidic PLA2 directly isolated from Bothrops jararacussu snake venom, was purified and submitted to various bioassays. BthA-I-PLA2 displayed high catalytic activity and induced Ca2+-dependent liposome disruption. Edema induced by this PLA2 was inhibited by indomethacin and dexamethasone, thus suggesting involvement of the cyclo-oxygenase pathway. BthA-I-PLA2 showed anticoagulant activity upon human plasma and inhibited phospholipid-dependent platelet aggregation induced by collagen or ADP. In addition, it displayed bactericidal activity against Escherichia coli and Staphylococcus aureus and antitumoral effect upon breast adrenocarcinoma as well as upon human leukemia T and Erlich ascitic tumor. Following chemical modification with p-bromophenacyl bromide, total loss of the enzymatic and pharmacological activities were observed. This is the first report on the isolation and identification of a cDNA encoding a complete acidic PLA2 from Bothrops venom, exhibiting bactericidal and antitumoral effects.

Isolation of an acidic phospholipase A2 from the venom of the snake Bothrops asper of Costa Rica: Biochemical and toxicological characterization☆

“…BaspPLA 2 -II did not present anticoagulant activity, an effect which has been reported for a number of acidic PLA 2 snake venoms [20,22]. Moreover, anti-platelet aggregating activity and hypotensive effect were also absent in BaspPLA 2 -II, again at variance with other acidic PLA 2 s [14,17,19e23,48e50].…”

CC-PLA2-1 and CC-PLA2-2, two Cerastes cerastes venom-derived phospholipases A2, inhibit angiogenesis both in vitro and in vivo

“…Although it has been reported that snake venom PLA 2 s exert a cytotoxic activity on tumor cells, 17,25 we showed that the two CC-PLA2s are not cytotoxic on human fibrosarcoma (HT1080) and melanoma (IGR39) cell lines. 22 In this study, we used HBMECs to check the effect of CC-PLA2s on angiogenesis.…”

“…Furthermore, they can show antiviral and bactericidal properties. [15][16][17] Several lines of evidence indicate that, in many instances, these effects are independent of the catalytic phospholipid hydrolysis. Moreover, to explain the susceptibility of a tissue to a particular PLA 2 , it has been proposed that venom PLA 2 s have selective membrane-binding sites that direct them to specific cellular targets, and that such binding is crucial in their mechanism of action.…”

Snake Venom Peptides: Promising Molecules with Anti-Tumor Effects

“…This anti-adhesive effect was due to the inhibition of 5 1and v-containing integrins [94]. A recent report demonstrated that Bth-A-I, a non-toxic PLA2 isolated from Bothrops jararacussu venom display an anti-tumoral effect upon breast adenocarcinoma as well as upon human leukaemia T and Erlich ascetic tumor [95]. MVL-PLA2 is a snake venom phospholipase purified from Macrovipera lebetina venom that inhibited adhesion and migration of human microvascular endothelial cells (HMEC-1) without being cytotoxic.…”