Identification of L-Amino Acid Oxidase (Mb-LAAO) with Antibacterial Activity in the Venom of Montivipera bornmuelleri, a Viper from Lebanon

Abstract

The L-amino acid oxidase (LAAO) is a multifunctional enzyme, able to partake in different activities including antibacterial activity. In this study, a novel LAAO (Mb-LAAO) was isolated from the venom of M. bornmuelleri snake using size exclusion chromatography followed by RP-HPLC and partially characterized. However, the molecular weight of the Mb-LAAO determined by ESI-MS and SDS-PAGE was 59 960.4 Da. Once the enzymatic activity test confirming the enzyme's identity (transformation of L-leucine) was done, the Mb-LAAO was evaluated for its antibacterial activity against Gram-negative bacteria. It showed a remarkable effect against M. morganii and K. pneumoniae. Moreover, no cytotoxic activity was observed for Mb-LAAO against human erythrocytes arguing for an exploration of its pharmaceutical interest.

Akbu-LAAO exhibits potent anti-tumor activity to HepG2 cells partially through produced H2O2 via TGF-β signal pathway

“…LAAOs play important roles in the biological activities for snake venom (SV). SV-LAAOs induce platelet aggregation and cell apoptosis, exhibit anti-microbial, anti-leishmaniasis, anti-tumor and anti-HIV activities 7 8 9 10 11 12 13 14 15 . SV-LAAOs were reported to exhibit cytotoxicity and apoptosis-induction towards leukemia HL-60 17 19 and K562 cells 20 , gastric carcinoma AGS and breast carcinoma MCF-7 cells 21 , colorectal carcinoma RKO cells 14 , melanoma B16 cells 17 , cervical carcinoma Hela cells 20 and lung carcinoma A549 cells 22 .…”

“…As one major snake venom (SV) component, LAAO commonly exists as homodimeric FAD-(flavin adenine dinucleotide) or FMN-(flavin mono-nucleotide) glycoprotein 4 5 6 . The anti-microbial, anti-platelet and anti-tumor functions 7 8 9 10 11 12 13 14 15 of SV-LAAOs were commonly reported to be mediated by enzymatic- released H 2 O 2 16 17 18 . However, the underlying action mechanisms are still unclear.…”

Vipericidins, Snake Venom Cathelicidin-Related Peptides, in the Milieu of Reptilian Antimicrobial Polypeptides

“…Another major component of snake venom consists of the L-amino acid oxidases (svLAAOs). The svLAAOs that were isolated from the venom of Montivipera bornmuelleri, a viper inhabiting Lebanese lands, exhibit efficacious antimicrobial activity against Gram-negative bacteria, specifically Morganella morganii and Klebsiella pneumonia -two infectious agents to humans -but was devoid of cytotoxicity to human erythrocytes (Rima et al 2013). In contrast, the heat-stable LAAO -an unusual form of snake venom LAAO toxin enzyme from the venom of the king cobra Ophiophagus hannah -showed moderate antimicrobial activity against Gramnegative bacteria (e.g., Escherichia coli, Pseudomonas aeruginosa, and K. pneumonia) but high effectiveness against Gram-positive bacteria, such as Staphylococcus aureus and S. epidermidis.…”

Cobra Cytotoxins: Structural Organization and Antibacterial Activity

“…In an earlier study [ 57 ], it was suggested that L -amino acid oxidase, a protein with a molecular weight of ~ 140 kDa present in the venom, is responsible for its antibacterial activity. Later, a number of oxidases from the venoms of different snakes were found to have antibacterial activity (e.g., [ 60 , 61 ]).…”

“…Many cytolytic peptides, such as melittin [ 68 ] latarcins [ 69 , 70 ], vaprines [ 71 , 72 ], and cathelicidin [ 73 ], can disrupt the membrane at similar concentrations. Another CT, namely CT3 from N. atra (otherwise known as A3, Table ), has been active not only against Grampositive ( S. aureus ), but also against Gram-negative ( E. coli ) microorganisms [ 74 ], even though previous reports indicated no activity for whole N. atra venom against E. coli [ 61 ]. These differences may be explained by the peculiarities of the individual E. coli strains that were used in the cited papers.…”