Interactions of the novel antimicrobial peptide buforin 2 with lipid bilayers: Proline as a translocation promoting factor
Interactions of the novel antimicrobial peptide buforin 2 with lipid bilayers: Proline as a translocation promoting factor
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DOI：
10.1021/bi0004549
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发表时间：
2000-07-25
期刊：
影响因子：
2.9
通讯作者：
Matsuzaki, K
中科院分区：
文献类型：
--
作者：
Kobayashi, S;Takeshima, K;Matsuzaki, K
Buforin 2是在亚洲蟾蜍Bufo bufo gargarizans的胃组织中发现的抗菌肽。具有+6净电荷的21个残基的肽显示出比爪蟾抗菌肽2（一种来自非洲爪蟾的膜透性抗微生物肽）高一个数量级的抗微生物活性[Park，C. B.，金，M。美国，和Kim，S. C.（1996）Biochem. Biophys.通信资源218，408-413]。在这项研究中，我们研究了蟾毒蛋白2与磷脂双层的相互作用，与爪蟾抗菌肽2相比，以深入了解蟾毒蛋白2的作用机制。使用等效Trp取代肽以荧光法监测肽-脂质相互作用。圆二色性测量显示buforin 2选择性地结合到由酸性磷脂组成的脂质体，假定二级结构类似于在三氟乙醇/水中的二级结构，其是围绕Pro（11）扭曲的具有柔性N-末端区域的两亲性螺旋[Yi，G.美国，帕克角，澳-地B.，Kim，S. C.的方法，和Cheong，C. 04 The Dog（1996）398，87-90]。Magainin 2诱导与脂质触发器偶联的脂质囊泡内捕获的荧光染料的泄漏。这些结果被解释为肽-脂质超分子复合物孔的形成[Matsuzaki，K.等人（1998）Biochim. Biophys. Acta 1376，391-400]。Buforin 2显示出弱得多的膜透化活性，尽管其较高的抗微生物活性。相反，buforin 2比magainin 2更有效地跨脂质双层转运。这些结果表明buforin 2的最终靶点不是细胞膜而是细胞内成分。此外，buforin 2没有诱导脂质翻转，表明buforin 2的易位机制与magainin 2不同。Pro的作用通过使用蟾毒灵2的P11 A衍生物来研究。该衍生物引起爪蟾抗菌肽2样二级结构和膜行为的变化。发现Pro（11）是buforin 2独特性质的一个非常重要的结构因子。
Buforin 2 is an antimicrobial peptide discovered in the stomach tissue of the Asian toad Bufo bufo gargarizans. The 21-residue peptide with +6 net charge shows antimicrobial activity an order of magnitude higher than that of magainin 2, a membrane-permeabilizing antimicrobial peptide from Xenopus laevis [Park, C. B., Kim, M. S., and Kim, S. C. (1996) Biochem. Biophys. Res. Commun. 218, 408-413]. In this study, we investigated the interactions of buforin 2 with phospholipid bilayers in comparison with magainin 2 to obtain insight into the mechanism of action of buforin 2. Equipotent Trp-substituted peptides were used to fluorometrically monitor peptide-lipid interactions. Circular dichroism measurements showed that buforin 2 selectively bound to liposomes composed of acidic phospholipids, assuming a secondary structure similar to that in trifluoroethanol/water, which is an amphipathic helix distorted around Pro(11) with a flexible N-terminal region [Yi, G. S., Park, C. B., Kim, S. C., and Cheong, C. (1996) FEES Lett. 398, 87-90]. Magainin 2 induced the leakage of a fluorescent dye entrapped within lipid vesicles coupled to Lipid flip-flop. These results have been interpreted as the formation of a peptide-lipid supramolecular complex pore [Matsuzaki, K. (1998) Biochim. Biophys. Acta 1376, 391-400]. Buforin 2 exhibited much weaker membrane permeabilization activity despite its higher antimicrobial activity. In contrast, buforin 2 was more efficiently translocated across lipid bilayers than magainin 2. These results suggested that the ultimate target of buforin 2 is not the membrane but intracellular components. Furthermore, buforin 2 induced no lipid flip-flop, indicating that the mechanism of translocation of buforin 2 is different from that of magainin 2. The role of Pro was investigated by use of a P11A derivative of buforin 2. The derivation caused a change to magainin 2-like secondary structure and membrane behavior. Pro(11) was found to be a very important structural factor for the unique properties of buforin 2.