1. Overview A 2. Protein Redesign B 2.1. Making Use of Native Proteins: Protein Redesign B 2.2. Protein Redesign Based on Functions C 2.2.1. Redesign of Zinc Finger Structural Sites C 2.2.2. Redesign of Zinc Hydrolytic Centers E 2.2.3. Redesign of Heme Centers J 2.2.4. Redesign of Nonheme Redox Centers M 2.2.5. Artificial Metalloenzymes for Regioand Enantioselective Catalysis AA 2.2.6. Redesigned Protein Assemblies as Nanoreactors AK 2.3. Summary AN 3. De Novo Design AN 3.1. A Minimalist Approach: Designing Proteins from Scratch AN 3.2. Interactions between De Novo Designed Peptides and Metal Ions AN 3.2.1. Heavy Metal Toxicity AO 3.2.2. De Novo Designed Metal Centers Based on β-Structures AT 3.2.3. Metal-Induced Protein Folding AV 3.3. De Novo Designed Functional Metalloproteins: The Grail Quest of Protein Design AX 3.3.1. De Novo Designed Hydrolytic Centers AX 3.3.2. De Novo Designed Electron Transfer Centers BB 3.3.3. Other Catalytic Centers BG 3.4. Summary BN 4. Perspective BO Author Information BO Corresponding Author BO Notes BO Biographies BO Abbreviations BR References BR

Protein design: toward functional metalloenzymes.

Using rational design, an engineered myoglobin-based catalyst capable of catalyzing the cyclopropanation of aryl-substituted olefins with catalytic proficiency (up to 46 800 turnovers) and excellent diastereo- and enantioselectivity (98–99.9 %) was developed. This transformation could be carried out in the presence of up to 20 g L−1 olefin substrate with no loss in diastereo- and/or enantioselectivity. Mutagenesis and mechanistic studies support a cyclopropanation mechanism mediated by an electrophilic, heme-bound carbene species and a model is provided to rationalize the stereopreference of the protein catalyst. This work shows that myoglobin constitutes a promising and robust scaffold for the development of biocatalysts with carbene-transfer reactivity.

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Highly diastereoselective and enantioselective olefin cyclopropanation using engineered myoglobin-based catalysts

Porphycene is an aromaticmacrocycle and a constitutional isomer of porphyrin. It and its derivatives display unique physical and optical properties, including strong absorptions in the red region of the UV-vis spectrum. These features have made porphycene and porphycene analogues appealing molecules for use in biomedical applications and in the design of new materials. This critical review provides a concise overview of the most important syntheses of porphycenes, as well as those of various functionalized derivatives and heteroatom containing analogues. (95 references.)

Porphycenes: synthesis and derivatives

The first example of a biocatalytic strategy for the synthesis of thioethers via an intermolecular carbene S–H insertion reaction is reported. Engineered variants of sperm whale myoglobin were found to efficiently catalyze this C–S bond forming transformation across a diverse set of aryl and alkyl mercaptan substrates and α-diazoester carbene donors, providing high conversions (60–99%) and high numbers of catalytic turnovers (1100–5400). Furthermore, the enantioselectivity of these biocatalysts could be tuned through mutation of amino acid residues within the distal pocket of the hemoprotein, leading to myoglobin variants capable of supporting asymmetric S–H insertions with up to 49% ee. Rearrangement experiments support a mechanism involving the formation of a sulfonium ylide generated upon attack of the thiol substrate to a heme-bound carbene intermediate.

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Intermolecular carbene S-H insertion catalysed by engineered myoglobin-based catalysts†.

Does CO poison Fe-based catalysts for ORR?

Sperm whale myoglobin, an oxygen storage hemoprotein, was successfully reconstituted with the iron porphycene having two propionates, 2,7-diethyl-3,6,12,17-tetramethyl-13,16-bis(carboxyethyl)porphycenatoiron. The physicochemical properties and ligand bindings of the reconstituted myoglobin were investigated. The ferric reconstituted myoglobin shows the remarkable stability against acid denaturation and only a low-spin characteristic in its EPR spectrum. The Fe(III)/Fe(II) redox potential (−190 mV vs NHE) determined by the spectroelectrochemical measurements was much lower than that of the wild-type. These results can be attributed to the strong coordination of His93 to the porphycene iron, which is induced by the nature of the porphycene ring symmetry. The O2 affinity of the ferrous reconstituted myoglobin is 2600-fold higher than that of the wild-type, mainly due to the decrease in the O2 dissociation rate, whereas the CO affinity is not so significantly enhanced. As a result, the O2 affinity of the reco...

Ligand binding properties of myoglobin reconstituted with iron porphycene: unusual O2 binding selectivity against CO binding.

Synthesis, structure, and chemical property of the first fluorine-containing porphycene.

The synthesis of the first fluorine-containing iron porphycenes, 2,7,12,17-tetraethyl-3,6,13,16-tetrakis(trifluoromethyl)porphycenatoiron(III) chloride [FePc(EtioCF3)]Cl and its μ-oxo dimer [FePc(E...

Synthesis, characterization, and autoreduction of a highly electron-deficient porphycenatoiron(III) with trifluoromethyl substituents.

Ligand binding properties of two kinds of reconstituted myoglobins with iron porphycene having propionates : Effect of β-pyrrolic position of two propionate side chains in porphycene framework

Takahiro Ikegami

Papers

Ligand binding properties of myoglobin reconstituted with iron porphycene: unusual O2 binding selectivity against CO binding.

Synthesis, structure, and chemical property of the first fluorine-containing porphycene.

Synthesis, characterization, and autoreduction of a highly electron-deficient porphycenatoiron(III) with trifluoromethyl substituents.

Ligand binding properties of two kinds of reconstituted myoglobins with iron porphycene having propionates : Effect of β-pyrrolic position of two propionate side chains in porphycene framework