Self-assembly and soluble aggregate behavior of computationally designed coiled-coil peptide bundles
Jeffrey A. Fagan, Darrin Pochan, Michael Haider, Huixi Zhang, Nairiti Sinha, Jeffrey Saven, Kristi Kiick
Coiled-coil peptides have proven useful in a range of materials applications ranging from the formation of well-defined fibrils to responsive hydrogels. The ability to design from first principles their oligomerization and subsequent higher order assembly offers their expanded use in producing new materials. Toward these ends, homo-tetrameric, antiparallel, coiled-coil, peptide bundles were designed computationally, synthesized via solid-phase methods, and their solution behavior characterized. Two different bundle-forming peptides were designed. On coiled coil formation, both bundles contained the same hydrophobic core. However, different exterior residues on the two different designs produced one bundle with an acidic isoelectric point and one with a basic isoelectric point. Both coiled-coil bundles are extremely stable with respect to temperature and were designed to remain soluble solution even at high concentrations. The coiled-coil tetramer was confirmed to be the dominant species in solution by sedimentation studies as well as small-angle neutron scattering; the form factor of individual bundles is well represented by a cylinder model. At higher concentrations, interparticle structure factor scattering is observed. Like many protein systems, the concentrated, synthetic bundles form soluble aggregates with interbundle distances that can be determined via a structure factor fit to scattering data. The data support the successful design of the soluble coiled-coil bundles and demonstrate that they are highly robust and stable in solution with soluble aggregate behavior similar to common protein solution behavior.
, Pochan, D.
, Haider, M.
, Zhang, H.
, Sinha, N.
, Saven, J.
and Kiick, K.
Self-assembly and soluble aggregate behavior of computationally designed coiled-coil peptide bundles, Soft Matter, [online], https://doi.org/10.1039/C8SM00435H
(Accessed December 10, 2023)