Characterization of histatin 5 with respect to amphipathicity, hydrophobicity, and effects on cell and mitochondrial membrane integrity excludes a candidacidal mechanism of pore formation
Characterization of histatin 5 with respect to amphipathicity, hydrophobicity, and effects on cell and mitochondrial membrane integrity excludes a candidacidal mechanism of pore formation
复制标题
DOI：
10.1074/jbc.m008229200
复制
发表时间：
2001-02-23
影响因子：
4.8
通讯作者：
Oppenheim, FG
中科院分区：
文献类型：
--
作者：
Helmerhorst, EJ;van't Hof, W;Oppenheim, FG
组胺素5是来自人唾液的具有抗真菌特性的24个残基的肽。我们最近证明，组胺素5易位穿过酵母细胞膜并靶向线粒体，提示了一种不寻常的抗真菌机制（Helmerhorst，E. J.，Breeuwer，P.，货车特霍夫，W.，Walgreen-Wetering，E.，乌门湖C. J.M.，Veerman，E. C.一、Nieuw Amerongen，k V.，和Abee，T.（1999）J.Biol.Chem.274，7286-7291）。本研究使用专门设计的组胺素5的合成类似物来阐明肽的两亲性、疏水性和采用α-螺旋结构的倾向与膜透化和杀真菌活性的关系的作用。研究包括圆二色性测量、对分离的线粒体的细胞质跨膜电位和呼吸作用的影响的评估、以及肽疏水性/两亲性关系的分析（Eisenberg，D.（1984）Annu. Reu. 53，595-623）。所用的14个残基的合成肽是dh-5，包括histatin 5的功能结构域，以及dhvar 1和dhvar 4，两者都被设计成最大化两亲特性。所得结果显示，两亲类似物表现出高杀真菌活性、形成α-螺旋的高倾向、耗散细胞质跨膜电位以及解偶联分离的线粒体的呼吸，类似于成孔肽PGLa（（P）在bar肽下具有N-末端甘氨酸和C-末端亮氨酸-酰胺）。相比之下，histatin 5和dh-5显示较少或没有这些特征。组胺素5和dh 5之间的这些功能特性的差异，一方面和dhvar 1，dhvar 4，和PGLa的另一方面，以及相关的预测亲和性膜的基础上的疏水性/两亲性分析。这些数据表明，唾液蛋白histatin 5发挥其抗真菌功能，通过其他机制比孔形成。
Histatin 5 is a 24-residue peptide from human saliva with antifungal properties. We recently demonstrated that histatin 5 translocates across the yeast membrane and targets to the mitochondria, suggesting an unusual antifungal mechanism (Helmerhorst, E. J., Breeuwer, P., van 't Hof, W., Walgreen-Weterings, E., Oomen, L. C. J. M., Veerman, E. C. I., Nieuw Amerongen, k V., and Abee, T. (1999) J. Biol. Chem. 274, 7286-7291). The present study used specifically designed synthetic analogs of histatin 5 to elucidate the role of peptide amphipathicity, hydrophobicity, and the propensity to adopt alpha -helical structures in relation to membrane permeabilization and fungicidal activity. Studies included circular dichroism measurements, evaluation of the effects on the cytoplasmic transmembrane potential and on the respiration of isolated mitochondria, and analysis of the peptide hydrophobicity/amphipathicity relationship (Eisenberg, D. (1984) Annu. Reu. Biochem. 53, 595-623). The 14-residue synthetic peptides used were dh-5, comprising the functional domain of histatin 5, and dhvar1 and dhvar4, both designed to maximize amphipathic characteristics. The results obtained show that the amphipathic analogs exhibited a high fungicidal activity, a high propensity to form an alpha -helix, dissipated the cytoplasmic transmembrane potential, and uncoupled the respiration of isolated mitochondria, similar to the pore-forming peptide PGLa ((P) under bar eptide with N-terminal Glycine and C-terminal Leucine-amide). In contrast, histatin 5 and dh-5 showed fewer or none of these features. The difference in these functional characteristics between histatin 5 and dh5 on the one hand and dhvar1, dhvar4, and PGLa on the other hand correlated well with their predicted affinity for membranes based on hydrophobicity/amphipathicity analysis. These data indicate that the salivary protein histatin 5 exerts its antifungal function through a mechanism other than pore formation.