Lima de Oliveira Aline, Maffud Cilli Eduardo, Ros Uris, Crusca Edson, Lanio María Eliana, Alvarez Carlos, Schreier Shirley, Aguiar Pertinhez Thelma, Spisni Alberto
Institute of Chemistry, University of Brasilia, Brasilia, DF, Brazil.
Department of Biochemistry and Chemical Technology, Institute of Chemistry, São Paulo State University, Araraquara, Brazil.
Biopolymers. 2018 Jan 23. doi: 10.1002/bip.23097.
Sticholysin II (StII) is a pore-forming actinoporin from the sea anemone Stichodactyla helianthus. A mechanistic model of its action has been proposed: proteins bind to cell membrane, insert their N-termini into the lipid core and assemble into homo-tetramer pores responsible for host-cell death. Because very likely the first 10 residues of StII N-terminus are critical for membrane penetration, to dissect the molecular details of that functionality, we studied two synthetic peptides: StII and StII . They show diverse haemolytic and candidacidal activity that correlate with distinct orientations in SDS micelles. NMR shows that StII partly inserts into the micelle, while StII lays on the micelle surface. These results justify the diverse concentration dependence of their candidacidal activity supposing a different mechanism of action and providing new hints on StII lytic activity at molecular level. Biotechnological application of these peptides, focused on the development of therapeutic immunocomplexes, may be envisaged.
刺参溶细胞素II（StII）是一种来自海葵日光海葵的成孔孔蛋白。已提出其作用的机制模型：蛋白质与细胞膜结合，将其N端插入脂质核心并组装成导致宿主细胞死亡的同型四聚体孔。由于StII N端的前10个残基很可能对膜穿透至关重要，为了剖析该功能的分子细节，我们研究了两种合成肽：StII和StII 。它们表现出不同的溶血和杀念珠菌活性，这与在SDS胶束中的不同取向相关。核磁共振显示StII部分插入胶束中，而StII位于胶束表面。这些结果证明了它们杀念珠菌活性的不同浓度依赖性，假设其作用机制不同，并在分子水平上为StII的裂解活性提供了新线索。可以设想这些肽在生物技术方面的应用，重点是治疗性免疫复合物的开发。
