@article{21749,
  abstract     = {The collagen triple helix assembles hierarchically into bundled oligomers, solvated networks, and fibers. Synthetic peptide assemblies, driven by supramolecular interactions, can form single triple helices through intrahelical amino acid pairs; however, the principles guiding interhelical associations into higher-order structures remain unclear. Here, we incorporate cation−π and electrostatic charge pairs to probe interhelical interactions and elucidate the mechanisms driving triple helix assembly into fibrils, nanotubes, and nanosheets. Introducing cation−π pairs into a fibrillating collagen mimetic resulted in D-periodic fibrils with pH-sensitive gelation. By alternating the presentation of electrostatic and cation−π pairs, the assembly of another D-periodic fibril featuring inner and outer triple-helical layers was resolved by cryo electron microscopy to a resolution of 8 Å. At physiological pH, antiparallel association of these triple helices leads to the formation of nanotubes. The packing behavior of triple helices correlates with the interhelical interactions, where parallel associations favor fibril formation and antiparallel interactions drive nanotube and nanosheet assembly. These self-assembling triple-helical peptides demonstrate how packing of higher-order structures can be tailored with supramolecular interactions and establish the relationship of different hierarchical collagen-mimetic assemblies as pH-dependent.},
  author       = {Cole, Carson C. and Kreutzberger, Mark A.B. and Klein, Kevin and Cahue, Kiana A. and Pogostin, Brett H. and Farsheed, Adam C. and Swain, Joseph W.R. and Bui, Thi H. and Dey, Arghadip and Makhoul, Jonathan T. and Dubackic, Marija and Pal, Antara and Olsson, Ulf and Šarić, Anđela and Egelman, Edward H. and Hartgerink, Jeffrey D.},
  issn         = {1526-4602},
  journal      = {Biomacromolecules},
  number       = {4},
  pages        = {2956--2965},
  publisher    = {American Chemical Society},
  title        = {{Supramolecular assembly of collagen-mimetic eptide D-periodic fibrils and nanoassemblies}},
  doi          = {10.1021/acs.biomac.6c00345},
  volume       = {27},
  year         = {2026},
}

@article{17239,
  abstract     = {Collagen is the most abundant protein in tissue scaffolds in live organisms. Collagen can self-assemble in vitro, which has led to a number of biotechnological and biomedical applications. To understand the dominant factors that participate in the formation of collagen nanostructures, here we study in real time and with nanoscale resolution the disassembly and reassembly of collagens. We implement a high-speed force microscope, which provides in situ high spatiotemporal resolution images of collagen nanostructures under changing pH conditions. The disassembly and reassembly are dominated by the electrostatic interactions among amino-acid residues of different molecules. Acidic conditions favor disassembly by neutralizing negatively charged residues. The process sets a net repulsive force between collagen molecules. A neutral pH favors the presence of negative and positively charged residues along the collagen molecules, which promotes their electrostatic attraction. Molecular dynamics simulations reproduce the experimental behavior and validate the electrostatic-based model of the disassembly and reassembly processes.},
  author       = {Garcia-Sacristan, Clara and Gisbert, Victor G. and Klein, Kevin and Šarić, Anđela and Garcia, Ricardo},
  issn         = {1936-086X},
  journal      = {ACS Nano},
  number       = {28},
  pages        = {18485--18492},
  publisher    = {American Chemical Society},
  title        = {{In operando imaging electrostatic-driven disassembly and reassembly of collagen nanostructures}},
  doi          = {10.1021/acsnano.4c03839},
  volume       = {18},
  year         = {2024},
}