An acidic phospholipase A₂ with antibacterial activity from Porthidium nasutum snake venom

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• 作者：Leidy Johana Vargas^a ; ^{johana2104@gmail.com} ; Mó ; nica Londoñ ; o^a ; Juan Carlos Quintana^a ; Carolina Rua^b ; Cesar Segura^c ; Bruno Lomonte^d ; Vitelbina Nú ; ñ ; ez^a ; ^e
• 关键词：PLA2 ; Phospholipase A2 ; PnPLA2 ; Phospholipase A2 of Porthidium nasutum ; MIC ; Minimum inhibitory concentration ; MBC ; Minimal bactericidal concentration
• 刊名：Comparative Biochemistry and Physiology ; Part B
• 出版年：2012
• 期刊代码：50_10964959
• 类别：bio
• 出版时间：April, 2012
• 卷：161
• 期：4
• 页码：341-347
• 文件大小：894 K

摘要

Snake venoms are complex mixtures of proteins among which both basic and acidic phospholipases A₂ (PLA₂s) can be found. Basic PLA₂s are usually responsible for major toxic effects induced by snake venoms, while acidic PLA₂s tend to have a lower toxicity. A novel PLA₂, here named PnPLA₂, was purified from the venom of Porthidium nasutum by means of RP-HPLC on a C18 column. PnPLA₂ is an acidic protein with a pI of 4.6, which migrates as a single band under both non-reducing and reducing conditions in SDS-PAGE. PnPLA₂ had a molecular mass of 15,802.6 Da, determined by ESI-MS. Three tryptic peptides of this protein were characterized by HPLC-nESI-MS/MS, and N-terminal sequencing by direct Edman degradation showing homology to other acidic PLA₂s from viperid venoms. PnPLA₂ displayed indirect hemolytic activity in agarose erythrocyte-egg yolk gels and bactericidal activity against Staphylococcus aureus in a dose-dependent manner, with a MIC and MBC of 32 渭g/mL. In addition, PnPLA₂ showed a potent inhibitory effect on platelet aggregation with doses up to 40 渭g/mL. This acidic PLA₂, in contrast to basic enzymes isolated from other viperid snake venoms, was not cytotoxic to murine skeletal muscle myoblasts C₂C₁₂. This is the first report on a bactericidal protein of Porthidium nasutum venom.