Please use this identifier to cite or link to this item:
Title: Purification, characterization and bactericidal activities of basic phospholipase A2 from the venom of Agkistrodon halys (Chinese pallas)
Authors: Perumal Samy, R. 
Gopalakrishnakone, P.
Ho, B.
Chow, V.T.K.
Keywords: Agkistrodon halys
Amino acid sequence
Phospholipase A2
Issue Date: Sep-2008
Citation: Perumal Samy, R., Gopalakrishnakone, P., Ho, B., Chow, V.T.K. (2008-09). Purification, characterization and bactericidal activities of basic phospholipase A2 from the venom of Agkistrodon halys (Chinese pallas). Biochimie 90 (9) : 1372-1388. ScholarBank@NUS Repository.
Abstract: Agkistrodon snake venoms contain a variety of phospholipases (PLA2), some of which are myotoxic. In this study, we used reverse-phase HPLC to purify PLA2 from the venom of Agkistrodon halys. The enzyme named as AgkTx-II, a basic Asp49 PLA2, has a molecular masses of 13,869.05. The amino acid sequence and molecular mass of AgkTx-II was identical to those of an Asp49 basic myotoxic PLA2 previously isolated from this venom. Antibacterial activities were tested by susceptibility and broth-dilution assays. AgkTx-II exerted a potent antibacterial activity against Staphylococcus aureus, Proteus vulgaris, Proteus mirabilis, and Burkholderia pseudomallei. The MIC values of AgkTx-II ranged between 85 and 2.76 μM and was most effective against S. aureus, P. vulgaris, P. mirabilis (MIC of 21.25 μM) and B. pseudomallei (MIC of 10.25 μM). This AgkTx-II rapidly killed S. aureus, P. vulgaris and B. pseudomallei in a dose-dependent manner. The effect of the AgkTx-II on bacterial membranes was evaluated by scanning and transmission electron microscopy. AgkTx-II caused morphological alterations apparent on their cellular surfaces, suggesting a killing mechanism based on membrane permeabilization and damage. Cytotoxicity was measured by XTT tetrazolium (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) and lactate dehydrogenase (LDH) assays using U-937 cells (monocytes). The AgkTx-II did not affect cell viability up to 500 μM concentrations but cell death was evident at 1000 μM concentration after 24 and 48 h. Furthermore, the repeated exposure of AgkTx-II (2-14 μM) treated mice showed different tissue alterations, mainly at the brain and kidney; the toxicological potential of AgkTx-II remains to be elucidated. The AgkTx-II exhibits no hemolytic action even at high doses (10-100 μM) in human erythrocytes. However, the AgkTx-II is believed to exert its bactericidal effect by permeabilizing the bacterial membrane by forming pores. In addition, the basic PLA2 AgkTx-II displays a bactericidal effect, which may be either dependent or independent of catalysis. © 2008 Elsevier Masson SAS. All rights reserved.
Source Title: Biochimie
ISSN: 03009084
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Feb 27, 2018


checked on Dec 31, 2018

Page view(s)

checked on Dec 8, 2022

Google ScholarTM


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.