Investigations into the ability of the peptide, HAL18, to interact with bacterial membranes
Investigations into the ability of the peptide, HAL18, to interact with bacterial membranes
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DOI：
10.1007/s00249-008-0352-6
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发表时间：
2008-11-01
影响因子：
2
通讯作者：
Phoenix, David A.
中科院分区：
文献类型：
--
作者：
Dennison, Sarah R.;Kim, Young Soo;Phoenix, David A.
Halocidin 是从 Halocynthia aurantium 血细胞中分离出来的，是一种异二聚肽，由两个 α 螺旋亚基 Hal15 和 Hal18 组成。 Hal18 对枯草芽孢杆菌 (MLC = 15 mu M) 和大肠杆菌 (MLC = 100 mu M) 具有抗菌特性。该肽被证明可以产生稳定的单层，这是α螺旋肽的特征，预计其方向平行于界面表面。恒定面积测定表明，Hal18 具有表面活性（4 μM），可诱导表面压力变化 > 30 mN m(-1)，这是膜相互作用肽的特征。该肽诱导模拟枯草芽孢杆菌膜（约 7 mN m(-1)）和大肠杆菌膜模拟物（约 4 mN m(-1)）的单层膜稳定的表面压力变化。 Hal18 很容易插入两性离子 DOPE 和阴离子 DOPG 单层中，在两种情况下都会引起约 8 mN m(-1) 的表面压力变化，这提供了相互作用不是头基特异性的证据。压缩等温线的热力学分析表明，Hal18 的存在使枯草芽孢杆菌膜不稳定 (Delta G (Mix) > 0)，这与其对大肠杆菌脂质提取物的稳定作用相反，这意味着不同的抗菌功效可能是由脂质堆积驱动的。
Halocidin was isolated from hemocytes, Halocynthia aurantium as a heterodimeric peptide consisting of two alpha-helical subunits, Hal15 and Hal18. Hal18 was shown to have antibacterial properties against Bacillus subtilis (MLC = 15 mu M) and Escherichia coli (MLC = 100 mu M). The peptide was shown to produce stable monolayers, which were characteristic of alpha-helical peptides predicted to orientate parallel to the surface of the interface. Constant area assays showed that Hal18 was surface active (4 mu M) inducing surface pressure changes > 30 mN m(-1) characteristic of membrane interactive peptides. The peptide induced stable surface pressure changes in monolayers that were mimetic of B. subtilis membranes (circa 7 mN m(-1)) and E. coli membrane-mimics (circa 4 mN m(-1)). Hal18 inserted readily into zwitterionic DOPE and anionic DOPG monolayers inducing surface pressure changes circa 8 mN m(-1) in both cases, providing evidence that interaction is not headgroup specific. Thermodynamic analysis of compression isotherms showed that the presence of Hal18 destabilised B. subtilis membranes (Delta G (Mix) > 0), which is in contrast to its stabilising effect on E. coli lipid extract implying the differential antimicrobial efficacy may be driven by lipid packing.