11 publications

11 publications

A Metal Ion Regulated Artificial Metalloenzyme

Roelfes, G.

Dalton Trans. 2017, 46, 4325-4330, 10.1039/C7DT00533D

An artificial metalloenzyme containing both a regulatory and a catalytic domain is selectively activated in presence of Fe2+ ions.


Metal: Fe
Ligand type: Bypyridine
Host protein: LmrR
Anchoring strategy: Covalent
Optimization: Genetic
Max TON: 14
ee: 75
PDB: ---
Notes: ---

Metal: Zn
Ligand type: Bypyridine
Host protein: LmrR
Anchoring strategy: Covalent
Optimization: Genetic
Max TON: 6
ee: 80
PDB: ---
Notes: ---

Artificial Metalloenzymes Derived from Bovine β-Lactoglobulin for the Asymmetric Transfer Hydrogenation of an Aryl Ketone – Synthesis, Characterization and Catalytic Activity

Salmain, M.

Dalton Trans. 2014, 43, 5482-5489, 10.1039/c3dt53253d

Protein hybrids resulting from the supramolecular anchoring to bovine β-lactoglobulin of fatty acid-derived Rh(iii) diimine complexes catalysed the asymmetric transfer hydrogenation of trifluoroacetophenone with up to 32% ee.


Metal: Rh
Ligand type: Cp*; Poly-pyridine
Host protein: ß-lactoglobulin
Anchoring strategy: Supramolecular
Optimization: Chemical
Reaction: Hydrogenation
Max TON: 14
ee: 32
PDB: ---
Notes: ---

Bovine Serum Albumin-Cobalt(II) Schiff Base Complex Hybrid: An Efficient Artificial Metalloenzyme for Enantioselective Sulfoxidation using Hydrogen Peroxide

Bian, H.-D.; Liang, H.

Dalton Trans. 2016, 45, 8061-8072, 10.1039/C5DT04507J

An artificial metalloenzyme (BSA–CoL) based on the incorporation of a cobalt(ii) Schiff base complex {CoL, H2L = 2,2′-[(1,2-ethanediyl)bis(nitrilopropylidyne)]bisphenol} with bovine serum albumin (BSA) has been synthesized and characterized.


Metal: Co
Ligand type: Amine; Phenolate
Anchoring strategy: Supramolecular
Optimization: Chemical
Reaction: Sulfoxidation
Max TON: 98
ee: 87
PDB: ---
Notes: ---

Chalcogenide Substitution in the [2Fe] Cluster of [FeFe]-Hydrogenases Conserves High Enzymatic Activity

Apfel, U.-P.; Happe, T.

Dalton Trans. 2017, 46, 16947-16958, 10.1039/C7DT03785F

Combination of biological and chemical methods allow for creation of [FeFe]-hydrogenases with an artificial synthetic cofactor.


Metal: Fe
Ligand type: CN; CO; Diselenolate
Anchoring strategy: Dative
Optimization: Chemical
Reaction: H2 evolution
Max TON: ---
ee: ---
PDB: 5OEF
Notes: ---

Ferritin Encapsulation of Artificial Metalloenzymes: Engineering a Tertiary Coordination Sphere for an Artificial Transfer Hydrogenase

Ward, T.R.

Dalton Trans. 2018, 47, 10837-10841, 10.1039/C8DT02224K

Ferritin, a naturally occuring iron-storage protein, plays an important role in nanoengineering and biomedical applications. Upon iron removal, apoferritin was shown to allow the encapsulation of an artificial transfer hydrogenase (ATHase) based on the streptavidin-biotin technology. The third coordination sphere, provided by ferritin, significantly influences the catalytic activity of an ATHase for the reduction of cyclic imines.


Metal: Ir
Ligand type: Amino-sulfonamide; Cp*
Host protein: Streptavidin (Sav)
Anchoring strategy: Supramolecular
Optimization: Chemical & genetic
Max TON: 3874
ee: 75
PDB: ---
Notes: ---

Neocarzinostatin-Based Hybrid Biocatalysts for Oxidation Reactions

Mahy, J.-P.; Ricoux, R.

Dalton Trans. 2014, 43, 8344-8354, 10.1039/c4dt00151f

An anionic iron(III)-porphyrin–testosterone conjugate 1-Fe has been synthesized and fully characterized. It has been further associated with a neocarzinostatin variant, NCS-3.24, to generate a new artificial metalloenzyme following the so-called ‘Trojan Horse’ strategy. This new 1-Fe-NCS-3.24 biocatalyst showed an interesting catalytic activity as it was found able to catalyze the chemoselective and slightly enantioselective (ee = 13%) sulfoxidation of thioanisole by H2O2. Molecular modelling studies show that a synergy between the binding of the steroid moiety and that of the porphyrin macrocycle into the protein binding site can explain the experimental results, indicating a better affinity of 1-Fe for the NCS-3.24 variant than testosterone and testosterone-hemisuccinate themselves. They also show that the Fe-porphyrin complex is sandwiched between the two subdomains of the protein providing with good complementarities. However, the artificial cofactor entirely fills the cavity and its metal ion remains widely exposed to the solvent which explains the moderate enantioselectivity observed. Some possible improvements in the “Trojan Horse” strategy for obtaining better catalysts of selective oxidations are presented.


Metal: Fe
Ligand type: Porphyrin
Anchoring strategy: Supramolecular
Optimization: ---
Reaction: Sulfoxidation
Max TON: 6
ee: 13
PDB: ---
Notes: ---

Oxidation Catalysis via Visible-Light Water Activation of a [Ru(bpy)3]2+ Chromophore BSA–Metallocorrole Couple

Gross, Z.; Mahy, J.-P.

Dalton Trans. 2016, 45, 706-710, 10.1039/c5dt04158a

Light induced enantioselective oxidation of an organic molecule with water as the oxygen atom source is demonstrated in a system where chirality is induced by a protein, oxygen atom transfer by a manganese corrole, and photocatalysis by ruthenium complexes.


Metal: Mn
Ligand type: Corrole
Anchoring strategy: Supramolecular
Optimization: ---
Reaction: Sulfoxidation
Max TON: 21
ee: 16
PDB: ---
Notes: Water as oxygen source

Semi-Synthesis of an Artificial Scandium(III) Enzyme with a β-Helical Bio-Nanotube

Ueno, T.

Dalton Trans. 2012, 41, 11424, 10.1039/C2DT31030A

We have succeeded in preparing semi-synthesized proteins bound to Sc3+ ion which can promote an epoxide ring-opening reaction. The Sc3+ binding site was created on the surface of [(gp5βf)3]2 (N. Yokoi et al., Small, 2010, 6, 1873) by introducing a cysteine residue for conjugation of a bpy moiety using a thiol–maleimide coupling reaction. Three cysteine mutants [(gp5βf_X)3]2 (X = G18C, L47C, N51C) were prepared to introduce a bpy in different positions because it had been reported that Sc3+ ion can serve as a Lewis-acid catalyst for an epoxide ring-opening reaction upon binding of epoxide to bpy and two –ROH groups. G18C_bpy with Sc3+ can accelerate the rate of catalysis of the epoxide ring-opening reaction and has the highest rate of conversion among the three mutants. The value is more than 20 times higher than that of the mixtures of [(gp5βf)3]2/2,2′-bipyridine and L-threonine/2,2′-bipyridine. The elevated activity was obtained by the cooperative effect of stabilizing the Sc3+ coordination and accumulation of substrates on the protein surface. Thus, we expect that the semi-synthetic approach can provide insights into new rational design of artificial metalloenzymes.


Metal: Sc
Ligand type: Bipyridine
Host protein: [(gp5βf)3]2
Anchoring strategy: Cystein-maleimide
Optimization: Genetic
Max TON: ---
ee: ---
PDB: ---
Notes: ---

Supramolecular Interactions Between Functional Metal Complexes and Proteins

Review

Duhme-Klair, A.K.

Dalton Trans. 2009, 10141, 10.1039/b915776j

This perspective illustrates the principles and applications of molecular recognition directed binding of transition metal complexes to proteins. After a brief introduction into non-covalent interactions and the importance of complementarity, the focus of the first part is on biological systems that rely on non-covalent forces for metal complex binding, such as proteins involved in bacterial iron uptake and the oxygen-storage protein myoglobin. The second part of the perspective will illustrate how the replacement of native with non-native metal-centres can give rise to artificial metalloenzymes with novel catalytic properties. Subsequently, examples of spectroscopic probes that exploit the characteristic photophysical properties of metal-complexes for the non-covalent labelling, visualisation and investigation of proteins will be described. Finally, the use of kinetically inert metal complexes as scaffolds in drug design will be discussed and it will be highlighted how the binding of metal ions or organometallic fragments to existing drugs or drug candidates can improve their activity or even alter their mode of action.


Notes: ---

Synthesis of Hybrid Transition-Metalloproteins via Thiol-Selective Covalent Anchoring of Rh-Phosphine and Ru-Phenanthroline Complexes

Kamer, P.C.J.; Laan, W.

Dalton Trans. 2010, 39, 8477, 10.1039/c0dt00239a

The preparation of hybrid transition metalloproteins by thiol-selective incorporation of organometallic rhodium- and ruthenium complexes is described. Phosphine ligands and two rhodium-diphosphine complexes bearing a carboxylic acid group were coupled to the cysteine of PYP R52G, yielding a metalloenzyme active in the rhodium catalyzed hydrogenation of dimethyl itaconate. The successful coupling was shown by 31P NMR spectroscopy and ESI mass spectroscopy. In addition wild-type PYP (PYP WT), PYP R52G and ALBP were successfully modified with a (η6-arene) ruthenium(II) phenanthroline complex via a maleimide linker.


Metal: Rh
Ligand type: COD; Phosphine
Anchoring strategy: Covalent
Optimization: ---
Reaction: Hydrogenation
Max TON: ---
ee: ---
PDB: 2PHY
Notes: ---

(η6-Arene) Ruthenium(II) Complexes and Metallo-Papain Hybrid as Lewis Acid Catalysts of Diels–Alder Reaction in Water

Salmain, M.

Dalton Trans. 2010, 39, 5605, 10.1039/c001630f

Covalent embedding of a (η6-arene) ruthenium(II) complex into the protein papain gives rise to a metalloenzyme displaying a catalytic efficiency for a Lewis acid-mediated catalysed Diels–Alder reaction enhanced by two orders of magnitude in water.


Metal: Ru
Ligand type: Benzene; Phenanthroline
Host protein: Papain (PAP)
Anchoring strategy: Covalent
Optimization: Chemical
Max TON: 440
ee: ---
PDB: ---
Notes: TOF = 220 h-1