Tan Huaxin, Luo Wenjuan, Wei Lin, Chen Bo, Li Wenxuan, Xiao Lehui, Manzhos Sergei, Liu Zhonghua, Liang Songping
Dynamic Optical Microscopic Imaging Laboratory, Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University , Changsha, Hunan 410081, P. R. China.
College of Life Sciences, Hunan Normal University , Changsha, Hunan 410081, P. R. China.
J Phys Chem B. 2016 Mar 31;120(12):3081-8. doi: 10.1021/acs.jpcb.5b12618. Epub 2016 Mar 18.
Lycosin-I, a peptide toxin derived from spider venom, has been demonstrated to be a promising candidate for the inhibition of tumor cell growth in vitro and in vivo by interacting with and penetrating the cell membrane. Owing to the shortage of an efficient characterization strategy, however, there is still a lack of detailed knowledge about the distribution of the stoichiometric composition information on this peptide in solution and on lipid membrane prior to the cellular uptake process, which is fundamentally important for the understanding of the anticancer mechanism. In this work, with objective-type total internal reflection fluorescence microscopy (TIRF), the distribution of the stoichiometric composition of lycosin-I in different solutions as well as on the lipid membrane was explored extensively on the basis of a statistical single molecule fluorescence intensity analysis for the first time. It was found that lycosin-I is mainly present in a monomer state in diverse physiological solutions regardless of the concentration of the peptide and the incubation time. However, on the lipid membrane, the fraction of small size oligomers increased as a function of time. Fusion of movable peptide molecules to those peptide oligomers with restricted motion on the lipid membrane was also observed.
狼蛛毒素-I是一种源自蜘蛛毒液的肽毒素，已被证明是一种有前景的候选物，可通过与细胞膜相互作用并穿透细胞膜来抑制肿瘤细胞在体外和体内的生长。然而，由于缺乏有效的表征策略，在细胞摄取过程之前，对于该肽在溶液和脂质膜上的化学计量组成信息的分布仍缺乏详细了解，而这对于理解其抗癌机制至关重要。在这项工作中，首次基于统计单分子荧光强度分析，利用物镜型全内反射荧光显微镜（TIRF）广泛探究了狼蛛毒素-I在不同溶液以及脂质膜上的化学计量组成分布。研究发现，无论肽的浓度和孵育时间如何，狼蛛毒素-I在多种生理溶液中主要以单体状态存在。然而，在脂质膜上，小尺寸寡聚体的比例随时间增加。还观察到可移动的肽分子与脂质膜上运动受限的肽寡聚体发生融合。
