Zhang Zihan, Blum Jacquelyn E, Guo Rui, Kloxin Christopher J, Saven Jeffery G, Pochan Darrin J
Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States.
Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
ACS Macro Lett. 2024 Nov 19;13(11):1591-1597. doi: 10.1021/acsmacrolett.4c00591. Epub 2024 Nov 7.
Parallel, homotetrameric coiled coils were computationally designed using 29 amino acid peptides. These parallel coiled coils, called "bundlemers", have symmetry, with all N-termini displayed from one end of the nanoparticle and all C-termini from the opposite end. This anisotropic display of the peptide termini allowed for the functionalization of two sets of nanoparticles with either maleimide or thiol functionality at the N-terminal region of the constituent peptides. The thiol-Michael conjugation reaction between the N-terminal end of complementary bundlemer nanoparticles formed monodisperse, rigid bundlemer dimer, called "dibundlemer", rods. The constituent, individual bundlemer nanoparticles were characterized with small-angle X-ray scattering (SAXS), Förster resonance energy transfer (FRET), and circular dichroism (CD) spectroscopy to confirm the parallel assembly of the coiled coils, consistent with the computational design. The dibundlemer rods were characterized with SAXS to reveal the uniform dibundlemer nature of the rods. Optical birefringence is observed in concentrated samples of the rods, with polarized optical microscopy (POM) revealing a nematic liquid crystalline behavior.
使用29个氨基酸的肽段通过计算设计出平行的同四聚体卷曲螺旋。这些平行的卷曲螺旋被称为“束聚物”，具有对称性，所有N端从纳米颗粒的一端伸出，所有C端从另一端伸出。肽末端的这种各向异性展示使得两组纳米颗粒能够在组成肽的N端区域用马来酰亚胺或硫醇官能团进行功能化。互补束聚物纳米颗粒N端之间的硫醇-迈克尔共轭反应形成了单分散的刚性束聚物二聚体，称为“双束聚物”棒状物。通过小角X射线散射（SAXS）、Förster共振能量转移（FRET）和圆二色性（CD）光谱对组成的单个束聚物纳米颗粒进行表征，以确认卷曲螺旋的平行组装，这与计算设计一致。通过SAXS对双束聚物棒状物进行表征，以揭示棒状物均匀的双束聚物性质。在棒状物的浓缩样品中观察到光学双折射，偏光显微镜（POM）显示出向列型液晶行为。
