title: Hybrid hydrogels cross-linked by genetically engineered coiled-coil block proteins.
abstract: Hybrid hydrogels of hydrophilic synthetic polymers cross-linked by protein modules undergo externally triggered volume transitions as a result of protein conformational changes. To investigate the influence of coiled-coil protein structure and stability on hydrogel volume transition, a series of block proteins containing interspersed naturally derived recombinant coiled-coils was synthesized. Proteins were characterized using circular dichroism, size exclusion chromatography, gel electrophoresis, and analytical ultracentrifugation. The block proteins formed self-associating oligomers and displayed thermal unfolding profiles indicative of a hierarchic higher-order structure. Hybrid hydrogels were assembled from an N-(2-hydroxypropyl)-methacrylamide (HPMA) copolymer and His-tagged block proteins through metal complexation. A temperature-induced decrease in hydrogel swelling was observed, and the onset temperature of the volume transition corresponded to the onset temperature of protein unfolding. We conclude that stimuli-responsive properties of hybrid hydrogels can be tailored by engineering the structure and properties of protein cross-links.
authors.affiliation: Departments of Bioengineering and Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Kopecek
authors.forename: R J
authors.initials: RJ
authors.lastname: Stewart
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001704:Biopolymers / Q000737:chemistry*; D003432:Cross-Linking Reagents; D004274:DNA, Recombinant / Q000235:genetics; D004355:Drug Stability; D020100:Hydrogels / Q000737:chemistry*; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011489:Protein Denaturation; D015202:Protein Engineering; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D013816:Thermodynamics
chemical_list: D001704:Biopolymers; D003432:Cross-Linking Reagents; D004274:DNA, Recombinant; D020100:Hydrogels; D046911:Macromolecular Substances; D011994:Recombinant Proteins