Supramolecular Assembly of His-Tagged Fluorescent Protein Guests within Coiled-Coil Peptide Crystal Hosts: Three-Dimensional Ordering and Protein Thermal Stability

The use of biomaterials for the inclusion andstabilization of biopolymers is an ongoing challenge. Herein, wedisclose three-dimensional (3D) coiled-coil peptide crystals withmetal ions that include and overgrow His-taggedfluorescentproteins within the crystal. The protein guests are found within twosymmetry-related growth sectors of the crystalline host that areassociated with faces of the growing crystal that display ligands formetal ions. Thefluorescent proteins are included within thishourglassregion of the crystals at a notably high level, displayorder within the crystal hosts, and demonstrate sufficiently tightpacking to enable energy transfer between a donor-acceptor pair.His-taggedfluorescent proteins display remarkable thermal stabilityto denaturation over extended periods of time (days) at high temperatures when within the crystals. Ultimately, this strategy mayprove useful for the prolonged storage of thermally sensitive biopolymer guests within a 3D crystalline matrix.

Automated summary

This study presents a method for including and overgrowing His-tagged fluorescent proteins within three-dimensional coiled-coil peptide crystals with metal ions. The fluorescent proteins are highly included within the crystal structure, displaying order and tight packing that enable energy transfer. This strategy may be useful for prolonged storage of thermally sensitive biopolymer guests within a 3D crystalline matrix.