Inhibition of Ice Recrystallization by Nanotube-Forming Cyclic Peptides
| Autor: | Romà Surís-Valls, Tim P. Hogervorst, Sandra M. C. Schoenmakers, Marco M. R. M. Hendrix, Lech Milroy, Ilja K. Voets |
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| Přispěvatelé: | Self-Organizing Soft Matter, Institute for Complex Molecular Systems, Macro-Organic Chemistry, Chemical Biology, ICMS Core |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Nanotubes
Polymers and Plastics Circular Dichroism Ice Bioengineering Growth Peptides Cyclic Biomaterials Microscopy Electron Transmission Budworm antifreeze protein Spectroscopy Fourier Transform Infrared Materials Chemistry Protein secondary structure Reagent Binding proteins Adsorption Nucleation protein Stability |
| Zdroj: | Biomacromolecules, 23(2), 520-529. American Chemical Society Biomacromolecules, 23(2), 520. American Chemical Society : Division of Carbohydrate Chemistry |
| ISSN: | 1525-7797 |
| Popis: | While most native ice-binding proteins are rigid, artificial (macro)molecular ice-binders are usually flexible. Realizing a regular array with precisely positioned ice-binding motifs on synthetic proteins, (macro)molecular ice-binders are thus challenging. Here, we exploit the predictable assembly of cyclic peptides into nanotubes as a starting point to prepare large, rigid ice-binders bearing an ice-binding site that is found in hyperactive ice-binding proteins in insects. First, we designed, synthesized, and purified cyclic octapeptide Lys2CP8 bearing a TaT motif to promote ice binding and investigated their solution assembly and activity using circular dichroism (CD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, light scattering (LS), cryogenic transmission electron microscopy (cryo-TEM), and ice recrystallization inhibition (IRI) assays. The cyclic peptide Lys2CP8 was synthesized in good yield using Fmoc chemistry and purified by reversed-phase HPLC. Upon dissolution in aqueous solutions, Lys2CP8 was observed to assemble in a pH- and concentration-dependent manner into objects with nanoscopic dimensions. LS revealed the presence of small and large aggregates at pH 3 and 11, held together through a network of intermolecular antiparallel β-sheets as determined by FTIR and CD spectroscopy. Cryo-TEM revealed the presence of one-dimensional objects at pH 3 and 11. These are mostly well-dispersed at pH 3 but appear to bundle at pH 11. Interestingly, the pH-dependent self-assembly behavior translates into a marked pH dependence of IRI activity. Lys2CP8 is IRI-active at pH 3 while inactive at pH 11 hypothetically because the ice-binding sites are inaccessible at pH 11 due to bundling. |
| Databáze: | OpenAIRE |
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