Molecular complementarity and structural heterogeneity within co-assembled peptide β-sheet nanofibers
| Autor: | Kong M. Wong, Anil K. Mehta, Anant K. Paravastu, Carol K. Hall, Yiming Wang, Grant E Larkin, Gregory A. Hudalla, Dillon T. Seroski |
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| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
0303 health sciences Nanofibers Beta sheet Peptide 010402 general chemistry Antiparallel (biochemistry) 01 natural sciences 0104 chemical sciences Amino acid 03 medical and health sciences Molecular dynamics Crystallography Protein structure chemistry Nanofiber Spectroscopy Fourier Transform Infrared Protein Conformation beta-Strand General Materials Science Fourier transform infrared spectroscopy Peptides 030304 developmental biology |
| Zdroj: | Nanoscale. 12:4506-4518 |
| ISSN: | 2040-3372 2040-3364 |
| Popis: | Self-assembling peptides have garnered an increasing amount of interest as a functional biomaterial for medical and biotechnological applications. Recently, β-sheet peptide designs utilizing complementary pairs of peptides composed of charged amino acids positioned to impart co-assembly behavior have expanded the portfolio of peptide aggregate structures. Structural characterization of these charge-complementary peptide co-assemblies has been limited. Thus, it is not known how the complementary peptides organize on the molecular level. Through a combination of solid-state NMR measurements and discontinuous molecular dynamics simulations, we investigate the molecular organization of King-Webb peptide nanofibers. KW+ and KW- peptides co-assemble into near stoichiometric two-component β-sheet structures as observed by computational simulations and 13C-13C dipolar couplings. A majority of β-strands are aligned with antiparallel nearest neighbors within the β-sheet as previously suggested by Fourier transform infrared spectroscopy measurements. Surprisingly, however, a significant proportion of β-strand neighbors are parallel. While charge-complementary peptides were previously assumed to organize in an ideal (AB)n pattern, dipolar recoupling measurements on isotopically diluted nanofiber samples reveal a non-negligible amount of self-associated (AA and BB) pairs. Furthermore, computational simulations predict these different structures can coexist within the same nanofiber. Our results highlight structural disorder at the molecular level in a charge-complementary peptide system with implications on co-assembling peptide designs. |
| Databáze: | OpenAIRE |
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