Bender, Gretchen MLehmann, AndreasZou, HonglingCheng, HongFry, H ChristopherEngel, DonTherien, Michael JBlasie, J KentSaven, Jeffery G.Roder, HeinrichDeGrado, William F2023-05-222023-05-222007-09-052016-06-22https://repository.upenn.edu/handle/20.500.14332/6107We describe the computational design of a single-chain four-helix bundle that noncovalently self-assembles with fully synthetic non-natural porphyrin cofactors. With this strategy, both the electronic structure of the cofactor as well as its protein environment may be varied to explore and modulate the functional and photophysical properties of the assembly. Solution characterization (NMR, UV-vis) of the protein showed that it bound with high specificity to the desired cofactors, suggesting that a uniquely structured protein and well-defined site had indeed been created. This provides a genetically expressed single-chain protein scaffold that will allow highly facile, flexible, and asymmetric variations to enable selective incorporation of different cofactors, surface-immobilization, and introduction of spectroscopic probes.This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see doi: http://dx.doi.org/10.1021%2Fja071199j">10.1021/ja071199jAmino Acid SequenceChromatography, GelCircular DichroismMetalloproteinsModels, MolecularMolecular Sequence DataNuclear Magnetic Resonance, BiomolecularPorphyrinsProtein Structure, SecondarySpectrophotometry, UltravioletThermodynamicsUltracentrifugationAmino Acid SequenceChromatographyGelCircular DichroismMetalloproteinsModelsMolecularMolecular Sequence DataNuclear Magnetic ResonanceBiomolecularPorphyrinsProtein StructureSecondarySpectrophotometryUltravioletThermodynamicsUltracentrifugationBiochemistryOrganic ChemistryArticle