Molecular structure and supramolecular assembly of a TGF-β1 mimetic oligopeptide

• Published in: Journal of molecular structure Vol. 1219; p. 128691
• Main Authors: Lourenço, Thiago C., Mello, Lucas R., Silva, Bruna B.S., Silva, Emerson R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05-11-2020
• Subjects: Atomic force microscopy; Nanoparticles; Peptide self-assembly; Secondary structure; Small-angle scattering; Transform growth factor; Nanoparticles; Atomic force microscopy; Transform growth factor; Peptide self-assembly; Small-angle scattering; Secondary structure
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2020.128691

The structural behavior and supramolecular assembly of pm26TGF-β1, a peptide fragment that mimics the binding domain of the transform growth factor-β1 (TGF-β1), has been investigated from molecular level up to the nano/micrometer scale. We have found that this short peptide forms stable aggregates above a critical concentration and, importantly, self-assembly is accompanied by transitions from random to α-helix and β-sheet conformations. These findings represent a relevant contribution from the present study because they experimentally demonstrate that this peptide acquires same secondary structure features found on active sites of the parent TGF-β1. We also demonstrate suitability of pm26TGF-β1 to fabricate ordered nanostructures on solid substrates through simple drop cast methods. This approach has been successfully used to produce discrete particles with regular oblate morphologies and sizes ranging from ∼100 nm up to ∼1 μm. Our findings demonstrating that conformation of pm26TGF-β1 self-assemblies reproduce secondary structures found on binding sites of the parent cytokine, alongside its suitability for fabricating ordered nanostructures on solid substrates, provide structural insights that encourage the exploration of these mimetic peptides in the production of nanostructured materials for applications related to cell regulation and immune response.
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•Structure of a TGF-β1 mimic peptide is experimentally studied.•Random-to-α-helix and β-sheet transitions are observed upon oligomerization.•Secondary structure in self-assemblies reproduces organization of TGF-β1 active sites.•Nanoparticles with spheroid shape are built onto solid substrate by simple drop casting.