Hierarchical Assembly of a Tetrameric Coiled‐Coil Into Cuboid Structures

ABSTRACT A tetrameric coiled‐coil peptide, TetNL , is used herein as a building block for hierarchical assembly into higher order structures. Assembly within phosphate buffer (pH 7.4) led to the rapid formation of micron‐sized fibers and cuboid structures, a process that could be shifted toward cuboid formation with agitation during the assembly process. Investigation of the packing of the cuboid assemblies by TEM demonstrated a regular banding pattern (4.6 nm) within the structures that was perpendicular to the length of the cuboids, a value that supports an end‐to end organization of the tetrameric coiled coils along the blocks. SWAXS analysis supports that the internal packing of the tetrameric coiled coil building blocks is a close‐packed hexagonal structure. These data represent an interesting comparison with a trimeric coiled coil peptide, TriNL , that forms hollow nanotubes with the same internal hexagonal packing. Modified TriNL has been used to generate numerous unique morphologies, and the data presented herein provide a distinct tetrameric building block that can also be exploited in this manner.