Antibacterial action of a heat-stable form of L-amino acid oxidase isolated from king cobra (Ophiophagus hannah) venom
Antibacterial action of a heat-stable form of L-amino acid oxidase isolated from king cobra (Ophiophagus hannah) venom
复制标题
DOI：
10.1016/j.cbpc.2010.11.001
复制
发表时间：
2011-03-01
影响因子：
3.9
通讯作者：
Sekaran, Shamala Devi
中科院分区：
文献类型：
--
作者：
Lee, Mui Li;Tan, Nget Hong;Sekaran, Shamala Devi
眼镜王蛇（Ophiophagus hannah）毒液中的主要L-氨基酸氧化酶（LAAO，EC 1.4.3.2）是蛇毒LAAO的一种特殊形式，因为它具有独特的结构特征和不寻常的热稳定性。采用微量肉汤稀释法测定眼镜王蛇毒LAAO对金黄色葡萄球菌、表皮葡萄球菌、铜绿假单胞菌、肺炎克雷伯菌和大肠埃希菌的抗菌作用。为了比较，还使用相同的条件检查了几种抗生素（头孢噻肟、卡那霉素、四环素、万古霉素和青霉素）的抗菌效果。眼镜王蛇毒LAAO对两种革兰氏阳性菌（S。金黄色葡萄球菌和对表皮葡萄球菌的最低抑菌浓度（MIC）分别为0.78 μ g/mL（0.006 μ M）和1.56 μ g/mL（0.012 μ M）。金黄色葡萄球菌和epidermidis。在重量基础上，MIC与测试的抗生素的MIC相当。然而，LAAO仅对三种测试的革兰氏阴性细菌（铜绿假单胞菌、克雷伯氏菌）具有中等有效性。肺炎杆菌和E.大肠杆菌），MIC范围为25 - 50 μ g/mL（0.2-0.4 μ M）。浓度为1 mg/mL的过氧化氢酶消除了LAAO的抗菌作用，表明该酶的抗菌作用涉及过氧化氢的产生。结合研究表明，眼镜王蛇毒LAAO与革兰氏阳性S.金黄色葡萄球菌和epidermidis，但对革兰氏阴性E.大肠杆菌和铜绿假单胞菌，表明特异性结合细菌是重要的有效的抗菌活性的酶。(C)2010年爱思唯尔公司All rights reserved.
The major L-amino acid oxidase (LAAO, EC 1.4.3.2) of king cobra (Ophiophagus hannah) venom is known to be an unusual form of snake venom LAAO as it possesses unique structural features and unusual thermal stability. The antibacterial effects of king cobra venom LAAO were tested against several strains of clinical isolates including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli using broth microdilution assay. For comparison, the antibacterial effects of several antibiotics (cefotaxime, kanamycin, tetracycline, vancomycin and penicillin) were also examined using the same conditions. King cobra venom LAAO was very effective in inhibiting the two Gram-positive bacteria (S. aureus and S. epidermidis) tested, with minimum inhibitory concentration (MIC) of 0.78 mu g/mL (0.006 mu M) and 1.56 mu g/mL (0.012 mu M) against S. aureus and S. epidermidis, respectively. The MICs are comparable to the MICs of the antibiotics tested, on a weight basis.. However, the LAAO was only moderately effective against three Gram-negative bacteria tested (P. aeruginosa, K. pneumoniae and E. coli), with MIC ranges from 25 to 50 mu g/mL (0.2-0.4 mu M). Catalase at the concentration of 1 mg/mL abolished the antibacterial effect of LAAO, indicating that the antibacterial effect of the enzyme involves generation of hydrogen peroxide. Binding studies indicated that king cobra venom LAAO binds strongly to the Gram-positive S. aureus and S. epidermidis, but less strongly to the Gram-negative E. coli and P. aeruginosa, indicating that specific binding to bacteria is important for the potent antibacterial activity of the enzyme. (C) 2010 Elsevier Inc. All rights reserved.