4 publications

4 publications

An Artificial Di-Iron Oxo-Orotein with Phenol Oxidase Activity

DeGrado, W.F.; Lombardi, A.

Nat. Chem. Biol. 2009, 5, 882-884, 10.1038/nchembio.257

Here we report the de novo design and NMR structure of a four-helical bundle di-iron protein with phenol oxidase activity. The introduction of the cofactor-binding and phenol-binding sites required the incorporation of residues that were detrimental to the free energy of folding of the protein. Sufficient stability was, however, obtained by optimizing the sequence of a loop distant from the active site.


Metal: Fe
Ligand type: Amino acid
Host protein: Due Ferri
Anchoring strategy: Dative
Optimization: Genetic
Reaction: Alcohol oxidation
Max TON: >50
ee: ---
PDB: 2KIK
Notes: kcat/KM ≈ 1380 M-1*min-1

Metal: Fe
Ligand type: Amino acid
Host protein: Due Ferri
Anchoring strategy: Dative
Optimization: Genetic
Reaction: Amine oxidation
Max TON: ---
ee: ---
PDB: 2KIK
Notes: kcat/KM ≈ 83 M-1*min-1

Computational Redesign of a Mononuclear Zinc Metalloenzyme for Organophosphate Hydrolysis

Baker, D.

Nat. Chem. Biol. 2012, 8, 294-300, 10.1038/NChemBio.777

The ability to redesign enzymes to catalyze noncognate chemical transformations would have wide-ranging applications. We developed a computational method for repurposing the reactivity of metalloenzyme active site functional groups to catalyze new reactions. Using this method, we engineered a zinc-containing mouse adenosine deaminase to catalyze the hydrolysis of a model organophosphate with a catalytic efficiency (kcat/Km) of ∼104 M−1 s−1 after directed evolution. In the high-resolution crystal structure of the enzyme, all but one of the designed residues adopt the designed conformation. The designed enzyme efficiently catalyzes the hydrolysis of the RP isomer of a coumarinyl analog of the nerve agent cyclosarin, and it shows marked substrate selectivity for coumarinyl leaving groups. Computational redesign of native enzyme active sites complements directed evolution methods and offers a general approach for exploring their untapped catalytic potential for new reactivities.


Metal: Zn
Ligand type: Amino acid
Anchoring strategy: Dative
Optimization: Genetic
Max TON: >140
ee: ---
PDB: 3T1G
Notes: kcat/KM ≈ 104 M-1*s-1

Spontaneous Activation of [FeFe]-Hydrogenases by an Inorganic [2Fe] Active Site Mimic

Happe, T.

Nat. Chem. Biol. 2013, 9, 607-609, 10.1038/Nchembio.1311

Hydrogenases catalyze the formation of hydrogen. The cofactor ('H-cluster') of [FeFe]-hydrogenases consists of a [4Fe-4S] cluster bridged to a unique [2Fe] subcluster whose biosynthesis in vivo requires hydrogenase-specific maturases. Here we show that a chemical mimic of the [2Fe] subcluster can reconstitute apo-hydrogenase to full activity, independent of helper proteins. The assembled H-cluster is virtually indistinguishable from the native cofactor. This procedure will be a powerful tool for developing new artificial H2-producing catalysts.


Metal: Fe
Ligand type: CN; CO; Dithiolate
Anchoring strategy: Dative
Optimization: Chemical
Reaction: H2 evolution
Max TON: ---
ee: ---
PDB: ---
Notes: ---

Structure and Dynamics of a Primordial Catalytic fold Generated by In Vitro Evolution

Seelig, B.

Nat. Chem. Biol. 2013, 9, 81-83, 10.1038/nchembio.1138

Engineering functional protein scaffolds capable of carrying out chemical catalysis is a major challenge in enzyme design. Starting from a noncatalytic protein scaffold, we recently generated a new RNA ligase by in vitro directed evolution. This artificial enzyme lost its original fold and adopted an entirely new structure with substantially enhanced conformational dynamics, demonstrating that a primordial fold with suitable flexibility is sufficient to carry out enzymatic function.


Metal: Zn
Ligand type: Amino acid
Anchoring strategy: Dative
Optimization: Genetic
Reaction: RNA ligation
Max TON: ---
ee: ---
PDB: 2LZE
Notes: ---