@article {65771, title = {Development of a Rubredoxin-Type Center Embedded in a de Dovo-Designed Three-Helix Bundle}, journal = {Biochemistry}, volume = {57}, year = {2018}, month = {03/2018}, pages = {2308 {\textendash} 2316}, abstract = {

Protein design is a powerful tool for interrogating the basic requirements for the function of a metal site in a way that allows for the selective incorporation of elements that are important for function. Rubredoxins are small electron transfer proteins with a reduction potential centered near 0 mV (vs normal hydrogen electrode). All previous attempts to design a rubredoxin site have focused on incorporating the canonical CXXC motifs in addition to reproducing the peptide fold or using flexible loop regions to define the morphology of the site. We have produced a rubredoxin site in an utterly different fold, a three-helix bundle. The spectra of this construct mimic the ultraviolet{\textendash}visible, M{\"o}ssbauer, electron paramagnetic resonance, and magnetic circular dichroism spectra of native rubredoxin. Furthermore, the measured reduction potential suggests that this rubredoxin analogue could function similarly. Thus, we have shown that an α-helical scaffold sustains a rubredoxin site that can cycle with the desired potential between the Fe(II) and Fe(III) states and reproduces the spectroscopic characteristics of this electron transport protein without requiring the classic rubredoxin protein fold.

}, doi = {10.1021/acs.biochem.8b00091}, url = {https://pubs-acs-org.accesdistant.sorbonne-universite.fr/doi/pdf/10.1021/acs.biochem.8b00091}, author = {Tebo, Alison G and Pinter, Tyler B J and Garc{\'\i}a-Serres, Ricardo and Speelman, Amy L and Tard, C{\'e}dric and S{\'e}n{\`e}que, Olivier and Blondin, Genevi{\`e}ve and Latour, Jean-Marc and Penner-Hahn, James and Lehnert, Nicolai and Pecoraro, Vincent L} } @article {65766, title = {Modifying the Steric Properties in the Second Coordination Sphere of Designed Peptides Leads to Enhancement of Nitrite Reductase Activity}, journal = {Angewandte Chemie International Edition}, volume = {57}, year = {2018}, month = {01/2018}, pages = {3954 {\textendash} 3957}, abstract = {

Protein design is a useful strategy to interrogate the protein structure-function relationship. We demonstrate using a highly modular 3-stranded coiled coil (TRI-peptide system) that a functional type 2 copper center exhibiting copper nitrite reductase (NiR) activity exhibits the highest homogeneous catalytic efficiency under aqueous conditions for the reduction of nitrite to NO and H2O. Modification of the amino acids in the second coordination sphere of the copper center increases the nitrite reductase activity up to 75-fold compared to previously reported systems. We find also that steric bulk can be used to enforce a three-coordinate CuI in a site, which tends toward two-coordination with decreased steric bulk. This study demonstrates the importance of the second coordination sphere environment both for controlling metal-center ligation and enhancing the catalytic efficiency of metalloenzymes and their analogues.

}, doi = {10.1002/anie.201712757}, url = {https://onlinelibrary.wiley.com/doi/full/10.1002/anie.201712757}, author = {Koebke, Karl J and Yu, Fangting and Salerno, Elvin and Stappen, Casey Van and Tebo, Alison G and Penner-Hahn, James E and Pecoraro, Vincent L} } @article {65773, title = {Intramolecular Photogeneration of a Tyrosine Radical in a Designed Protein}, journal = {ChemPhotoChem}, volume = {1}, year = {2017}, month = {02/2017}, pages = {89 {\textendash} 92}, abstract = {

Long-distance biological electron transfer occurs through a hopping mechanism and often involves tyrosine as a high potential intermediate, for example in the early charge separation steps during photosynthesis. Protein design allows for the development of minimal systems to study the underlying principles of complex systems. Herein, we report the development of the first ruthenium-linked designed protein for the photogeneration of a tyrosine radical by intramolecular electron transfer.

}, doi = {10.1002/cptc.201600044}, url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cptc.201600044}, author = {Tebo, Alison G and Quaranta, Annamaria and Herrero, Christian and Pecoraro, Vincent L and Aukauloo, Ally} } @article {65782, title = {Artificial metalloenzymes derived from three-helix bundles.}, journal = {Current Opinion in Chemical Biology}, volume = {25C}, year = {2015}, month = {01/2015}, pages = {65 {\textendash} 70}, abstract = {

Three-helix bundles and coiled-coil motifs are well-established de novo designed scaffolds that have been investigated for their metal-binding and catalytic properties. Satisfaction of the primary coordination sphere for a given metal is sufficient to introduce catalytic activity and a given structure may catalyze different reactions dependent on the identity of the incorporated metal. Here we describe recent contributions in the de novo design of metalloenzymes based on three-helix bundles and coiled-coil motifs, focusing on non-heme systems for hydrolytic and redox chemistry.

}, doi = {10.1016/j.cbpa.2014.12.034}, author = {Tebo, Alison G and Pecoraro, Vincent L} } @article {65781, title = {Variable primary coordination environments of Cd(II) binding to three helix bundles provide a pathway for rapid metal exchange.}, journal = {Metallomics}, volume = {7}, year = {2015}, month = {10/2015}, pages = {1555 {\textendash} 1561}, abstract = {

Members of the ArsR/SmtB family of transcriptional repressors, such as CadC, regulate the intracellular levels of heavy metals like Cd(II), Hg(II), and Pb(II). These metal sensing proteins bind their target metals with high specificity and affinity, however, a lack of structural information about these proteins makes defining the coordination sphere of the target metal difficult. Lingering questions as to the identity of Cd(II) coordination in CadC are addressed via protein design techniques. Two designed peptides with tetrathiolate metal binding sites were prepared and characterized, revealing fast exchange between CdS3O and CdS4 coordination spheres. Correlation of (111m)Cd PAC spectroscopy and (113)Cd NMR spectroscopy suggests that Cd(II) coordinated to CadC is in fast exchange between CdS3O and CdS4 forms, which may provide a mechanism for rapid sensing of heavy metal contaminants by this regulatory protein.

}, doi = {10.1039/c5mt00228a}, author = {Tebo, Alison G and Hemmingsen, Lars and Pecoraro, Vincent L} } @article {65783, title = {Protein design: toward functional metalloenzymes.}, journal = {Chemical reviews}, volume = {114}, year = {2014}, month = {03/2014}, pages = {3495 {\textendash} 3578}, doi = {10.1021/cr400458x}, author = {Yu, Fangting and Cangelosi, Virginia M and Zastrow, Melissa L and Tegoni, Matteo and Plegaria, Jefferson S and Tebo, Alison G and Mocny, Catherine S and Ruckthong, Leela and Qayyum, Hira and Pecoraro, Vincent L} }