Coraiola M, Lo Cantore P, Lazzaroni S, Evidente A, Iacobellis N S, Dalla Serra M
ITC-CNR Istituto di Biofisica, via Sommarive 18, I-38050 Povo (Trento), Italy.
Biochim Biophys Acta. 2006 Nov;1758(11):1713-22. doi: 10.1016/j.bbamem.2006.06.023. Epub 2006 Jul 14.
The activity of the White Line Inducing Principle (WLIP) and tolaasin I, produced by virulent strains of Pseudomonas reactans and Pseudomonas tolaasii, respectively, was comparatively evaluated on lipid membranes. Both lipodepsipeptides were able to induce the release of calcein from large unilamellar vesicles. Their activity was dependent on the toxin concentration and liposome composition and in particular it increased with the sphingomyelin content of the membrane. Studies of dynamic light scattering suggested a detergent-like activity for WLIP at high concentration (> 27 microM). This effect was not detected for tolaasin I at the concentrations tested (< 28 microM). Differences were also observed in lipodepsipeptides secondary structure. In particular, the conformation of the smaller WLIP changed slightly when it passed from the buffer solution to the lipid environment. On the contrary, we observed a valuable increment in the helical content of tolaasin I which was inserted in the membrane core and oriented parallel to the lipid acyl chains.
分别由致病力强的反应假单胞菌和托拉氏假单胞菌产生的白线诱导因子（WLIP）和托拉辛I对脂质膜的活性进行了比较评估。这两种脂肽都能够诱导钙黄绿素从大单层囊泡中释放出来。它们的活性取决于毒素浓度和脂质体组成，特别是随着膜中鞘磷脂含量的增加而增加。动态光散射研究表明，高浓度（>27 microM）的WLIP具有类似去污剂的活性。在所测试的浓度（<28 microM）下，未检测到托拉辛I有这种效应。在脂肽二级结构上也观察到差异。特别是，较小的WLIP从缓冲溶液进入脂质环境时，其构象略有变化。相反，我们观察到插入膜核心并与脂质酰基链平行排列的托拉辛I的螺旋含量有显著增加。
