Peptoid Residues Make Diverse, Hyperstable Collagen Triple-Helices.
Kessler, J.L., Kang, G., Qin, Z., Kang, H., Whitby, F.G., Cheatham, T.E., Hill, C.P., Li, Y., Yu, S.M.(2021) J Am Chem Soc 143: 10910-10919
- PubMed: 34255504
- DOI: https://doi.org/10.1021/jacs.1c00708
- Primary Citation of Related Structures:
7JX4, 7JX5 - PubMed Abstract:
As the only ribosomally encoded N-substituted amino acid, proline promotes distinct secondary protein structures. The high proline content in collagen, the most abundant protein in the human body, is crucial to forming its hallmark structure: the triple-helix. For over five decades, proline has been considered compulsory for synthetic designs aimed at recapitulating collagen's structure and properties. Here we describe that N-substituted glycines (N-glys), also known as peptoid residues, exhibit a general triple-helical propensity similar to or greater than proline, enabling synthesis of stable triple-helical collagen mimetic peptides (CMPs) with unprecedented side chain diversity. Supported by atomic-resolution crystal structures as well as circular dichroism and computational characterizations spanning over 30 N-gly-containing CMPs, we discovered that N-glys stabilize the triple-helix primarily by sterically preorganizing individual chains into the polyproline-II helix. We demonstrated that N-glys with exotic side chains including a "click"-able alkyne and a photosensitive side chain enable CMPs for functional applications including the spatiotemporal control of cell adhesion and migration. The structural principles uncovered in this study open up opportunities for a new generation of collagen-mimetic therapeutics and materials.
Organizational Affiliation:
Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah 84112, United States.