Abstract
Although macrochirality of peptides’ supramolecular structures has been found to play important roles in biological activities, how macrochirality is determined by the molecular chirality of the constituted amino acids is still unclear. Here, two chiral peptides, Ac-LKLHLHLQLKLLLVLFLFLALK-NH2 (KK-11) and Ac-DKDHDHDQDKDL DVDFDFDADK-NH2 (KKd-11), which were composed entirely of either L- or D-amino acids, were designed for studying the chiral characteristics of the supramolecular microstructures. It was found that monocomponent KK-11 or KKd-11 self-assembled into right- or left-handed helical nanofibrils, respectively. However, when they co-assembled with concentration ratios varied from 1:9 to 9:1, achiral nanowire-like structures were formed. Both circular dichroism and Fourier transform infrared spectra indicated that the secondary structures changed when the peptides co-assembled. MD simulations indicated that KK-11 or KKd-11 exhibited a strong propensity to self-assemble into right-handed or left-handed nanofibrils, respectively. However, when KK-11 and KKd-11 were both presented in a solution, they had a higher probability to co-assemble instead of self-sort. MD simulations indicated that, in their mixtures, they formed nanowires without handedness feature, a good agreement with experimental observation. Our results shed light on the molecular mechanisms of the macrochirality of peptide supramolecular microstructures.
Highlights
Chirality is a universal phenomenon in biological systems (Hegstrom and Kondepudi, 1990; Goldanskii and Kuzmin, 1991; Bada, 1995; Liu et al, 2015)
KK-11 or KKd-11 Self-Assembled Into Helical Nanofibrils
In our systems, the macrochirality of the assembled nanofibrils was determined by the chirality of the amino acids (L- or D-type) that composed the peptide (KK-11 or KKd-11)
Summary
Chirality is a universal phenomenon in biological systems (Hegstrom and Kondepudi, 1990; Goldanskii and Kuzmin, 1991; Bada, 1995; Liu et al, 2015). Many isomeric peptides with the same amino acid composition have shown different selfassembly behaviors, which resulted in different supramolecular morphologies (Dzwolak et al, 2007; Rubin et al, 2008; Adhikari et al, 2011; Wang et al, 2017). It was found that the homochiral tripeptides (LFLFLV and DFDFDV) exhibited poor self-assembling properties; the heterochiral peptides (DFLFLV and LFDFDV) were able to self-assemble into chiral nanofibrils (Marchesan et al, 2014). Investigation on hierarchical selfassembling peptides comprising of chiral amino acids would shed light on the formation mechanism of macrochirality
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
