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Shichijo K, Kametani Y, Shiota Y, Yoshizawa K, Fujitsuka M, Shimakoshi H. Effect of Macrocycles on the Photochemical and Electrochemical Properties of Cobalt-Dehydrocorrin Complex: Formation and Investigation of Co(I) Species. Inorg Chem 2023; 62:11785-11795. [PMID: 37307067 DOI: 10.1021/acs.inorgchem.3c00882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Co(II)-pyrocobester (P-Co(II)), a dehydrocorrin complex, was semisynthesized from vitamin B12 (cyanocobalamin), and its photochemical and electrochemical properties were investigated and compared to those of the cobester (C-Co(II)), the cobalt-corrin complex. The UV-vis absorptions of P-Co(II) in CH2Cl2, ascribed to the π-π* transition, were red-shifted compared to those of C-Co(II) due to the π-expansion of the macrocycle in the pyrocobester. The reversible redox couple of P-Co(II) was observed at E1/2 = -0.30 V vs Ag/AgCl in CH3CN, which was assigned to the Co(II)/Co(I) redox couple by UV-vis, ESR, and molecular orbital analysis. This redox couple was positively shifted by 0.28 V compared to that of C-Co(II). This is caused by the high electronegativity of the dehydrocorrin macrocycle, which was estimated by DFT calculations for the free-base ligands. The reactivity of the Co(I)-pyrocobester (P-Co(I)) was evaluated by the reaction with methyl iodide in CV and UV-vis to form a photosensitive Co(III)-CH3 complex (P-Co(III)-CH3). The properties of the excited state of P-Co(I), *Co(I), were also investigated by femtosecond transient absorption (TA) spectroscopy. The lifetime of *Co(I) was estimated to be 29 ps from the kinetic trace at 587 nm. The lifetime of *Co(I) became shorter in the presence of Ar-X, such as iodobenzonitrile (1a), bromobenzonitrile (1b), and chlorobenzonitrile (1c), and the rate constants of electron transfer (ET) between the *Co(I) and Ar-X were determined to be 2.9 × 1011 M-1 s-1, 4.9 × 1010 M-1 s-1, and 1.0 × 1010 M-1 s-1 for 1a, 1b, and 1c, respectively.
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Affiliation(s)
- Keita Shichijo
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Yohei Kametani
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Yoshihito Shiota
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
| | - Mamoru Fujitsuka
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Osaka 567-0047, Japan
| | - Hisashi Shimakoshi
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Nishi-ku, Motooka, 744, Fukuoka 819-0395, Japan
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Liu Y, Lai KL, Vong K. Transition Metal Scaffolds Used To Bring New‐to‐Nature Reactions into Biological Systems. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Yifei Liu
- Department of Chemistry The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon Hong Kong China
| | - Ka Lun Lai
- Department of Chemistry The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon Hong Kong China
| | - Kenward Vong
- Department of Chemistry The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon Hong Kong China
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Pott M, Tinzl M, Hayashi T, Ota Y, Dunkelmann D, Mittl PRE, Hilvert D. Noncanonical Heme Ligands Steer Carbene Transfer Reactivity in an Artificial Metalloenzyme*. Angew Chem Int Ed Engl 2021; 60:15063-15068. [PMID: 33880851 DOI: 10.1002/anie.202103437] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Indexed: 11/06/2022]
Abstract
Changing the primary metal coordination sphere is a powerful strategy for tuning metalloprotein properties. Here we used amber stop codon suppression with engineered pyrrolysyl-tRNA synthetases, including two newly evolved enzymes, to replace the proximal histidine in myoglobin with Nδ -methylhistidine, 5-thiazoylalanine, 4-thiazoylalanine and 3-(3-thienyl)alanine. In addition to tuning the heme redox potential over a >200 mV range, these noncanonical ligands modulate the protein's carbene transfer activity with ethyl diazoacetate. Variants with increased reduction potential proved superior for cyclopropanation and N-H insertion, whereas variants with reduced Eo values gave higher S-H insertion activity. Given the functional importance of histidine in many enzymes, these genetically encoded analogues could be valuable tools for probing mechanism and enabling new chemistries.
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Affiliation(s)
- Moritz Pott
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Matthias Tinzl
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Takahiro Hayashi
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Yusuke Ota
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Daniel Dunkelmann
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
| | - Peer R E Mittl
- Department of Biochemistry, University of Zürich, 8057, Zürich, Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry, ETH Zürich, 8093, Zürich, Switzerland
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Pott M, Tinzl M, Hayashi T, Ota Y, Dunkelmann D, Mittl PRE, Hilvert D. Noncanonical Heme Ligands Steer Carbene Transfer Reactivity in an Artificial Metalloenzyme**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Moritz Pott
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | - Matthias Tinzl
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | - Takahiro Hayashi
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | - Yusuke Ota
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
| | | | - Peer R. E. Mittl
- Department of Biochemistry University of Zürich 8057 Zürich Switzerland
| | - Donald Hilvert
- Laboratory of Organic Chemistry ETH Zürich 8093 Zürich Switzerland
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Ariyasu S, Stanfield JK, Aiba Y, Shoji O. Expanding the applicability of cytochrome P450s and other haemoproteins. Curr Opin Chem Biol 2020; 59:155-163. [PMID: 32781431 DOI: 10.1016/j.cbpa.2020.06.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/15/2020] [Accepted: 06/22/2020] [Indexed: 12/20/2022]
Abstract
Cytochrome P450BM3 has long been regarded as a promising candidate for use as a biocatalyst, owing to its excellent efficiency for the hydroxylation of unactivated C-H bonds. However, because of its high substrate specificity, its possible applications have been severely limited. Consequently, various approaches have been proposed to overcome the enzyme's natural limitations, thereby expanding its substrate scope to encompass non-native substrates, evoking chemoselectivity, regioselectivity and stereoselectivity and enabling previously inaccessible chemical conversions. Herein, these approaches will be classified into three categories: (1) mutagenesis including directed evolution, (2) haem substitution with artificial cofactors and (3) use of substrate mimics, 'decoy molecules'. Herein, we highlight the representative work that has been conducted in above three categories for discussion of the future outlook of P450BM3 in green chemistry.
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Affiliation(s)
- Shinya Ariyasu
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Joshua Kyle Stanfield
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Yuichiro Aiba
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Osami Shoji
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan; JST-CREST, Japan.
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