Nanotube width difference in assemblies consisting of E22L vs E22V

A residue substitution from Leu (E22L) to Val (E22V), essentially a single methyl's difference, in the amyloid beta-42 16-22 truncation of KLVFFAE resulted in nanotubes of drastically different widths. While E22L nanotubes registered at 38 nm, E22V nanotubes registered at 278 nm. Peptides were assembled at 1.3 mM in 40% acetonitrile and 0.1 % trifluoroacetic acid.在KLVFFAE的淀粉样β-42（amyloid beta-42）16-22截短片段中，亮氨酸（Leu，E22L）向缬氨酸（Val，E22V）的单残基取代仅存在一个甲基的差异，却使得所形成的纳米管宽度出现极大差异。其中E22L突变体对应的纳米管直径为38 nm，而E22V突变体对应的纳米管直径可达278 nm。实验中，肽类在1.3 mM浓度、含40%乙腈与0.1%三氟乙酸的混合溶剂中完成自组装。