title: Accessing Three-Dimensional Crystals with Incorporated Guests through Metal-Directed Coiled-Coil Peptide Assembly.
abstract: Obtaining three-dimensional (3D) protein and peptide crystals on demand requires a precisely orchestrated hierarchical assembly of biopolymer building blocks. In this work, we disclose a metal-ion-mediated strategy to assemble trimeric coiled-coil peptides in a head-to-tail fashion into linear strands with interstrand interactions. This design led to hexagonal 3D peptide crystal formation within 30 min in the presence of divalent metal ions. The crystal morphology could be controlled by varying the metal ion/peptide ratio, resulting in hexagonal discs to rods. Diffraction studies elucidated the head-to-tail arrangement of the coiled-coil linear strands and their hexagonal, antiparallel packing within the crystal. Unsatisfied ligands at the hexagonal ends of the crystals were harnessed as a powerful means to direct His-tagged fluorophores to distinct locations within the crystals. Overall, the designed hierarchical assembly provides a facile means to obtain 3D peptide crystals and incorporate His-tag-based cargoes and may have potential use in drug delivery and sensor design.
authors: Department of Chemistry, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States.
authors: Manish
authors: M
authors: Nepal
authors: Department of Chemistry, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States.
authors: Michael J
authors: MJ
authors: Sheedlo
authors: Department of Chemistry, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States.
authors: Chittaranjan
authors: C
authors: Das
authors: Department of Chemistry, Purdue University , 560 Oval Drive, West Lafayette, Indiana 47907, United States.
authors: Jean
authors: J
authors: Chmielewski
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary
chemical_list: D008670:Metals; D010455:Peptides