1
|
Wunderlich H, Alvaro RAC, Wenschuh H, Schnatbaum K. New method for peptide purification based on selective removal of truncation peptide impurities after SPPS with orthogonal capping. J Pept Sci 2023; 29:e3496. [PMID: 37060350 DOI: 10.1002/psc.3496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/06/2023] [Accepted: 04/12/2023] [Indexed: 04/16/2023]
Abstract
Peptide purification by high-performance liquid chromatography (HPLC) is associated with high solvent consumption, relatively large effort and lack of efficient parallelization. As an alternative, many catch-and-release (c&r) purification methods have been developed over the last decades to enable the efficient parallel purification of peptides originating from solid-phase peptide synthesis (SPPS). However, with one exception, none of the c&r systems has been widely established in industry and academia until today. Herein, we present an entirely new chromatography-free purification concept for peptides synthesized on a solid support, termed reactive capping purification (RCP). The RCP method relies on the capping of truncation peptides arising from incomplete coupling of amino acids during SPPS with a reactive tag. The reactive tag contains a masked functionality that, upon liberation during cleavage from the resin, enables straightforward purification of the peptide by incubation with a resin-bound reactive moiety. In this work, two different reactive tags based on masked thiols were developed. Capping with these reactive tags during SPPS led to effective modification of truncated sequences and subsequent removal of the latter by chemoselective reaction with a maleimide-functionalized solid support. By introducing a suitable protecting group strategy, the thiol-based RCP method described here could also be successfully applied to a thiol-containing peptide. Finally, the purification of a 15-meric peptide by the RCP method was demonstrated. The developed method has low solvent consumption, has the potential for efficient parallelization, uses readily available reagents, and is experimentally simple to perform.
Collapse
Affiliation(s)
- Hendrik Wunderlich
- Division of Peptide Biochemistry, TUM School of Life Sciences, Technische Universität München (TUM), Freising, Germany
| | | | | | | |
Collapse
|
2
|
Lu X, Wang S, Qin JH. Isolating Fe-O 2 Intermediates in Dioxygen Activation by Iron Porphyrin Complexes. Molecules 2022; 27:4690. [PMID: 35897870 PMCID: PMC9332324 DOI: 10.3390/molecules27154690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/12/2022] [Accepted: 07/18/2022] [Indexed: 11/30/2022] Open
Abstract
Dioxygen (O2) is an environmentally benign and abundant oxidant whose utilization is of great interest in the design of bioinspired synthetic catalytic oxidation systems to reduce energy consumption. However, it is unfortunate that utilization of O2 is a significant challenge because of the thermodynamic stability of O2 in its triplet ground state. Nevertheless, nature is able to overcome the spin state barrier using enzymes, which contain transition metals with unpaired d-electrons facilitating the activation of O2 by metal coordination. This inspires bioinorganic chemists to synthesize biomimetic small-molecule iron porphyrin complexes to carry out the O2 activation, wherein Fe-O2 species have been implicated as the key reactive intermediates. In recent years, a number of Fe-O2 intermediates have been synthesized by activating O2 at iron centers supported on porphyrin ligands. In this review, we focus on a few examples of these advances with emphasis in each case on the particular design of iron porphyrin complexes and particular reaction environments to stabilize and isolate metal-O2 intermediates in dioxygen activation, which will provide clues to elucidate structures of reactive intermediates and mechanistic insights in biological processes.
Collapse
Affiliation(s)
- Xiaoyan Lu
- College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, China; (S.W.); (J.-H.Q.)
| | | | | |
Collapse
|
3
|
Liu Y, Denisov IG, Grinkova YV, Sligar SG, Kincaid JR. P450 CYP17A1 Variant with a Disordered Proton Shuttle Assembly Retains Peroxo‐Mediated Lyase Efficiency. Chemistry 2020; 26:16846-16852. [DOI: 10.1002/chem.202003181] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Indexed: 11/07/2022]
Affiliation(s)
- Yilin Liu
- Department of Chemistry Marquette University 1414W Clybourn Street Milwaukee WI 53233 USA
| | - Ilia G. Denisov
- Departments of Biochemistry and Chemistry University of Illinois 116 Morrill Hall 505 S. Goodwin Avenue Urbana IL 61801 USA
| | - Yelena V. Grinkova
- Departments of Biochemistry and Chemistry University of Illinois 116 Morrill Hall 505 S. Goodwin Avenue Urbana IL 61801 USA
| | - Stephen G. Sligar
- Departments of Biochemistry and Chemistry University of Illinois 116 Morrill Hall 505 S. Goodwin Avenue Urbana IL 61801 USA
| | - James R. Kincaid
- Department of Chemistry Marquette University 1414W Clybourn Street Milwaukee WI 53233 USA
| |
Collapse
|
4
|
Mukherjee M, Dey A. A heterogeneous bio-inspired peroxide shunt for catalytic oxidation of organic molecules. Chem Commun (Camb) 2020; 56:11593-11596. [PMID: 32852503 DOI: 10.1039/d0cc03468a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heme enzymes are capable of catalytically oxidising organic substrates using peroxide via the formation of a high-valent intermediate. Iron porphyrins with three different axial ligands are created on self-assembled monolayer-modified gold electrodes, which can oxidize C-H bonds and epoxidize alkenes efficiently. The kinetic isotope effects suggest that the hydrogen atom transfer reaction by a highly reactive oxidant is likely to be the rate-determining step. Effect of different axial ligands and different secondary structures of the iron porphyrin confirms that the thiolate axial ligand with a hydrophobic distal pocket is the most efficient for this oxidation chemistry.
Collapse
Affiliation(s)
- Manjistha Mukherjee
- School of Chemical Science, Indian Association for the Cultivation of Science, Kolkata, India.
| | | |
Collapse
|
5
|
Usai R, Kaluka D, Mak PJ, Liu Y, Kincaid JR. Resonance Raman spectroscopic studies of peroxo and hydroperoxo intermediates in lauric acid (LA)-bound cytochrome P450 119. J Inorg Biochem 2020; 208:111084. [PMID: 32470906 DOI: 10.1016/j.jinorgbio.2020.111084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 03/07/2020] [Accepted: 03/29/2020] [Indexed: 11/30/2022]
Abstract
Cytochromes P450 bind and cleave dioxygen to generate a potent intermediate compound I, capable of hydroxylating inert hydrocarbon substrates. Cytochrome P450 119, a bacterial cytochrome P450 that serves as a good model system for the study of the intermediate states in the P450 catalytic cycle. CYP119 is found in high temperature and sulfur rich environments. Though the natural substrate and redox partner are still unknown, a potential application of such thermophilic P450s is utilizing them as biocatalysts in biotechnological industry; e.g., the synthesis of organic compounds otherwise requiring hostile environments like extremes of pH or temperature. In the present work the oxygenated complex of this enzyme bound to lauric acid, a surrogate substrate known to have a good binding affinity, was studied by a combination of cryoradiolysis and resonance Raman spectroscopy, to trap and characterize active site structures of the key fleeting enzymatic intermediates, including the peroxo and hydroperoxo species.
Collapse
Affiliation(s)
- Remigio Usai
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, United States
| | - Daniel Kaluka
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, United States
| | - Piotr J Mak
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, United States
| | - Yilin Liu
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, United States
| | - James R Kincaid
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, United States.
| |
Collapse
|
6
|
Amanullah S, Singha A, Dey A. Tailor made iron porphyrins for investigating axial ligand and distal environment contributions to electronic structure and reactivity. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.01.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
7
|
Adam SM, Wijeratne GB, Rogler PJ, Diaz DE, Quist DA, Liu JJ, Karlin KD. Synthetic Fe/Cu Complexes: Toward Understanding Heme-Copper Oxidase Structure and Function. Chem Rev 2018; 118:10840-11022. [PMID: 30372042 PMCID: PMC6360144 DOI: 10.1021/acs.chemrev.8b00074] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heme-copper oxidases (HCOs) are terminal enzymes on the mitochondrial or bacterial respiratory electron transport chain, which utilize a unique heterobinuclear active site to catalyze the 4H+/4e- reduction of dioxygen to water. This process involves a proton-coupled electron transfer (PCET) from a tyrosine (phenolic) residue and additional redox events coupled to transmembrane proton pumping and ATP synthesis. Given that HCOs are large, complex, membrane-bound enzymes, bioinspired synthetic model chemistry is a promising approach to better understand heme-Cu-mediated dioxygen reduction, including the details of proton and electron movements. This review encompasses important aspects of heme-O2 and copper-O2 (bio)chemistries as they relate to the design and interpretation of small molecule model systems and provides perspectives from fundamental coordination chemistry, which can be applied to the understanding of HCO activity. We focus on recent advancements from studies of heme-Cu models, evaluating experimental and computational results, which highlight important fundamental structure-function relationships. Finally, we provide an outlook for future potential contributions from synthetic inorganic chemistry and discuss their implications with relevance to biological O2-reduction.
Collapse
Affiliation(s)
- Suzanne M. Adam
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Gayan B. Wijeratne
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Patrick J. Rogler
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Daniel E. Diaz
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - David A. Quist
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Jeffrey J. Liu
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kenneth D. Karlin
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| |
Collapse
|
8
|
Mak PJ, Duggal R, Denisov IG, Gregory MC, Sligar SG, Kincaid JR. Human Cytochrome CYP17A1: The Structural Basis for Compromised Lyase Activity with 17-Hydroxyprogesterone. J Am Chem Soc 2018; 140:7324-7331. [PMID: 29758981 DOI: 10.1021/jacs.8b03901] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The multifunctional enzyme, cytochrome P450 (CYP17A1), plays a crucial role in the production of androgens, catalyzing two key reactions on pregnenolone (PREG) and progesterone (PROG), the first being a 17-hydroxylation to generate 17-OH PREG and 17-OH PROG, with roughly equal efficiencies. The second is a C-C bond scission or "lyase" reaction in which the C17-C20 bond is cleaved, leading to the eventual production of powerful androgens, whose involvement in the proliferation of prostate cancer has generated intense interest in developing inhibitors of CYP17A1. For humans, the significance of the C-C bond cleavage of 17-OH PROG is lessened, because it is about 50 times less efficient than for 17-OH PREG in terms of kcat/Km. Recognizing the need to clarify relevant reaction mechanisms involved with such transformations, we first report studies of solvent isotope effects, results of which are consistent with a Compound I mediated PROG hydroxylase activity, yet exclude this intermediate as a participant in the formation of androstenedione (AD) via the lyase reaction. This finding is also supported by a combination of cryoreduction and resonance Raman spectroscopy that traps and structurally characterizes the key hemiketal reaction intermediates. Adding to a previous study of PREG and 17-OH PREG metabolism, the current work provides definitive evidence for a more facile protonation of the initially formed ferric peroxo-intermediate for 17-OH PROG-bound CYP17A1, compared to the complex with 17-OH PREG. Importantly, Raman characterization also reveals an H-bonding interaction with the terminal oxygen of the peroxo fragment, rather than with the proximal oxygen, as is present for 17-OH PREG. These factors would favor a diminished lyase activity of the sample with 17-OH PROG relative to the complex with 17-OH PREG, thereby providing a convincing structural explanation for the dramatic differences in activity for these lyase substrates in humans.
Collapse
Affiliation(s)
- Piotr J Mak
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53233 , United States
| | - Ruchia Duggal
- Department of Biochemistry , University of Illinois at Urbana-Champaign , 505 S. Goodwin , Urbana , Illinois 61801 , United States
| | - Ilia G Denisov
- Department of Biochemistry , University of Illinois at Urbana-Champaign , 505 S. Goodwin , Urbana , Illinois 61801 , United States
| | - Michael C Gregory
- Department of Biochemistry , University of Illinois at Urbana-Champaign , 505 S. Goodwin , Urbana , Illinois 61801 , United States
| | - Stephen G Sligar
- Department of Biochemistry , University of Illinois at Urbana-Champaign , 505 S. Goodwin , Urbana , Illinois 61801 , United States.,Department of Chemistry , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - James R Kincaid
- Department of Chemistry , Marquette University , Milwaukee , Wisconsin 53233 , United States
| |
Collapse
|
9
|
Fang M, Wilson SR, Suslick KS. A siloxyl bis-pocket thiolate-tailed Fe(III) porphyrin complex. J PORPHYR PHTHALOCYA 2018. [DOI: 10.1142/s1088424617500912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We report the synthesis and characterization of a bis-pocket iron(III) porphyrin complex that has a covalently attached siloxy thiolate group as the axial ligand. As a new cytochrome P450 model compound, this siloxyl bis-pocket thiolate-tailed iron(III) porphyrin is easily synthesized and is surprisingly stable under air due to the extreme steric protection of the siloxy pockets on both faces of the porphyrin. A single-crystal XRD structure has been determined; the Fe–S bond distance is 2.237 (7) Å with Fe–N bond distances of 2.100 (8) and the Fe is 0.5 Å out of the mean porphyrin plane. The Fe–S bond distance in the siloxy thiolate-tailed iron(III) porphyrin is very similar to that in cytochrome P450 and this structure represents a very rare crystallographically-characterized five-coordinate high spin alkylthiolate-tailed ferric porphyrin. EPR spectrum of this compound showed g values and an E/D ratio very similar to those of cytochrome P450 (CYP450) enzyme, demonstrating the importance of using a very basic thiolate group as the axial ligand in P450 model studies. UV-vis studies of its reduced form with carbon monoxide shows a hyper spectrum, which is characteristic of carbonyl complexes of Fe(II)porphyrin thiolates.
Collapse
Affiliation(s)
- Ming Fang
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Scott R. Wilson
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Kenneth S. Suslick
- School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| |
Collapse
|
10
|
Mak PJ, Denisov IG. Spectroscopic studies of the cytochrome P450 reaction mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2018; 1866:178-204. [PMID: 28668640 PMCID: PMC5709052 DOI: 10.1016/j.bbapap.2017.06.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/22/2017] [Indexed: 10/19/2022]
Abstract
The cytochrome P450 monooxygenases (P450s) are thiolate heme proteins that can, often under physiological conditions, catalyze many distinct oxidative transformations on a wide variety of molecules, including relatively simple alkanes or fatty acids, as well as more complex compounds such as steroids and exogenous pollutants. They perform such impressive chemistry utilizing a sophisticated catalytic cycle that involves a series of consecutive chemical transformations of heme prosthetic group. Each of these steps provides a unique spectral signature that reflects changes in oxidation or spin states, deformation of the porphyrin ring or alteration of dioxygen moieties. For a long time, the focus of cytochrome P450 research was to understand the underlying reaction mechanism of each enzymatic step, with the biggest challenge being identification and characterization of the powerful oxidizing intermediates. Spectroscopic methods, such as electronic absorption (UV-Vis), electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), electron nuclear double resonance (ENDOR), Mössbauer, X-ray absorption (XAS), and resonance Raman (rR), have been useful tools in providing multifaceted and detailed mechanistic insights into the biophysics and biochemistry of these fascinating enzymes. The combination of spectroscopic techniques with novel approaches, such as cryoreduction and Nanodisc technology, allowed for generation, trapping and characterizing long sought transient intermediates, a task that has been difficult to achieve using other methods. Results obtained from the UV-Vis, rR and EPR spectroscopies are the main focus of this review, while the remaining spectroscopic techniques are briefly summarized. This article is part of a Special Issue entitled: Cytochrome P450 biodiversity and biotechnology, edited by Erika Plettner, Gianfranco Gilardi, Luet Wong, Vlada Urlacher, Jared Goldstone.
Collapse
Affiliation(s)
- Piotr J Mak
- Department of Chemistry, Saint Louis University, St. Louis, MO, United States.
| | - Ilia G Denisov
- Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, IL, United States.
| |
Collapse
|
11
|
Meininger DJ, Chee-Garza M, Arman HD, Tonzetich ZJ. Gallium(III) Tetraphenylporphyrinates Containing Hydrosulfide and Thiolate Ligands: Structural Models for Sulfur-Bound Iron(III) Hemes. Inorg Chem 2016; 55:2421-6. [DOI: 10.1021/acs.inorgchem.5b02822] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Daniel J. Meininger
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio Texas 78249, United States
| | - Max Chee-Garza
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio Texas 78249, United States
| | - Hadi D. Arman
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio Texas 78249, United States
| | - Zachary J. Tonzetich
- Department of Chemistry, University of Texas at San Antonio (UTSA), San Antonio Texas 78249, United States
| |
Collapse
|
12
|
Mittra K, Sengupta K, Singha A, Bandyopadhyay S, Chatterjee S, Rana A, Samanta S, Dey A. Second sphere control of spin state: Differential tuning of axial ligand bonds in ferric porphyrin complexes by hydrogen bonding. J Inorg Biochem 2016; 155:82-91. [DOI: 10.1016/j.jinorgbio.2015.11.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 10/02/2015] [Accepted: 11/10/2015] [Indexed: 11/16/2022]
|
13
|
Oszajca M, Franke A, Brindell M, Stochel G, van Eldik R. Redox cycling in the activation of peroxides by iron porphyrin and manganese complexes. ‘Catching’ catalytic active intermediates. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2015.01.013] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
14
|
Lau N, Ziller JW, Borovik AS. Sulfonamido tripods: tuning redox potentials via ligand modifications. Polyhedron 2015; 85:777-782. [PMID: 25419035 DOI: 10.1016/j.poly.2014.09.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A series of FeII-OH2 complexes were synthesized with ligands based on the tetradentate sulfonamido tripod N,N',N"-[2,2',2"-nitrilotris(ethane-2,1-diyl)]-tris-({R-Ph}-sulfonamido). These complexes differ by the substituent on the aryl rings and were fully characterized, including their molecular structures via X-ray diffraction methods. All the complexes were five-coordinate with trigonal bipyramidal geometry. A linear correlation was observed between the electronic effects of each ligand, given by the Hammett constants of the para-substituents, and the potential of the FeII/FeIII redox couple, which were determined using cyclic voltammetry. It was found that the range of redox potentials for the complexes spanned approximately 160 mV.
Collapse
Affiliation(s)
- Nathanael Lau
- Department of Chemistry, University of California - Irvine, 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| | - Joseph W Ziller
- Department of Chemistry, University of California - Irvine, 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| | - A S Borovik
- Department of Chemistry, University of California - Irvine, 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| |
Collapse
|
15
|
Savela R, Wärnå J, Murzin DY, Leino R. Iron catalyzed halogenation of benzylic aldehydes and ketones. Catal Sci Technol 2015. [DOI: 10.1039/c5cy00067j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple iron-catalyzed method for halogenation of aromatic carbonyl compounds in one step has been developed, combined with mechanistic investigation.
Collapse
Affiliation(s)
- Risto Savela
- Johan Gadolin Process Chemistry Centre
- Laboratory of Organic Chemistry
- Åbo Akademi University
- 20500 Åbo
- Finland
| | - Johan Wärnå
- Johan Gadolin Process Chemistry Centre
- Industrial Chemistry and Reaction Engineering
- Åbo Akademi University
- 20500 Åbo
- Finland
| | - Dmitry Yu. Murzin
- Johan Gadolin Process Chemistry Centre
- Industrial Chemistry and Reaction Engineering
- Åbo Akademi University
- 20500 Åbo
- Finland
| | - Reko Leino
- Johan Gadolin Process Chemistry Centre
- Laboratory of Organic Chemistry
- Åbo Akademi University
- 20500 Åbo
- Finland
| |
Collapse
|
16
|
Das PK, Mittra K, Dey A. Spectroscopic characterization of a phenolate bound FeII–O2adduct: gauging the relative “push” effect of a phenolate axial ligand. Chem Commun (Camb) 2014; 50:5218-20. [DOI: 10.1039/c3cc47528j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
17
|
Samanta S, Das PK, Chatterjee S, Sengupta K, Mondal B, Dey A. O2 Reduction Reaction by Biologically Relevant Anionic Ligand Bound Iron Porphyrin Complexes. Inorg Chem 2013; 52:12963-71. [DOI: 10.1021/ic4020652] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Subhra Samanta
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Pradip Kumar Das
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Sudipta Chatterjee
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Kushal Sengupta
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Biswajit Mondal
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| | - Abhishek Dey
- Department
of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata, India 700032
| |
Collapse
|
18
|
Latifi R, Sainna MA, Rybak-Akimova EV, de Visser SP. Does Hydrogen-Bonding Donation to Manganese(IV)-Oxo and Iron(IV)-Oxo Oxidants Affect the Oxygen-Atom Transfer Ability? A Computational Study. Chemistry 2013; 19:4058-68. [DOI: 10.1002/chem.201202811] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 11/16/2012] [Indexed: 12/21/2022]
|
19
|
García-Sánchez MA, Rojas-González F, Menchaca-Campos EC, Tello-Solís SR, Quiroz-Segoviano RIY, Diaz-Alejo LA, Salas-Bañales E, Campero A. Crossed and linked histories of tetrapyrrolic macrocycles and their use for engineering pores within sol-gel matrices. Molecules 2013; 18:588-653. [PMID: 23292327 PMCID: PMC6270341 DOI: 10.3390/molecules18010588] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 12/20/2012] [Accepted: 12/25/2012] [Indexed: 11/17/2022] Open
Abstract
The crossed and linked histories of tetrapyrrolic macrocycles, interwoven with new research discoveries, suggest that Nature has found in these structures a way to ensure the continuity of life. For diverse applications porphyrins or phthalocyanines must be trapped inside solid networks, but due to their nature, these compounds cannot be introduced by thermal diffusion; the sol-gel method makes possible this insertion through a soft chemical process. The methodologies for trapping or bonding macrocycles inside pristine or organo-modified silica or inside ZrO₂ xerogels were developed by using phthalocyanines and porphyrins as molecular probes. The sizes of the pores formed depend on the structure, the cation nature, and the identities and positions of peripheral substituents of the macrocycle. The interactions of the macrocyclic molecule and surface Si-OH groups inhibit the efficient displaying of the macrocycle properties and to avoid this undesirable event, strategies such as situating the macrocycle far from the pore walls or to exchange the Si-OH species by alkyl or aryl groups have been proposed. Spectroscopic properties are better preserved when long unions are established between the macrocycle and the pore walls, or when oligomeric macrocyclic species are trapped inside each pore. When macrocycles are trapped inside organo-modified silica, their properties result similar to those displayed in solution and their intensities depend on the length of the alkyl chain attached to the matrix. These results support the prospect of tuning up the pore size, surface area, and polarity inside the pore cavities in order to prepare efficient catalytic, optical, sensoring, and medical systems. The most important feature is that research would confirm again that tetrapyrrolic macrocycles can help in the development of the authentic pore engineering in materials science.
Collapse
Affiliation(s)
- Miguel A García-Sánchez
- Departamento de Quimica, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Vicentina, D. F. 09340, Mexico.
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Nakazawa J, Hagiwara J, Shimazaki Y, Tani F, Naruta Y. Synthesis, Characterization, and Small Hydrocarbon Encapsulation of Dicavitand-Porphyrins. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2012. [DOI: 10.1246/bcsj.20120107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jun Nakazawa
- Department of Material and Life Chemistry, Faculty of Engineering, Kanagawa University
| | - Jun Hagiwara
- Institute for Materials Chemistry and Engineering, Kyushu University
| | | | - Fumito Tani
- Institute for Materials Chemistry and Engineering, Kyushu University
| | - Yoshinori Naruta
- Institute for Materials Chemistry and Engineering, Kyushu University
| |
Collapse
|
21
|
Takahashi A, Yamaki D, Ikemura K, Kurahashi T, Ogura T, Hada M, Fujii H. Effect of the Axial Ligand on the Reactivity of the Oxoiron(IV) Porphyrin π-Cation Radical Complex: Higher Stabilization of the Product State Relative to the Reactant State. Inorg Chem 2012; 51:7296-305. [DOI: 10.1021/ic3006597] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Akihiro Takahashi
- Institute for Molecular
Science
and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787,
Japan
- Department of Functional
Molecular
Science, The Graduate University for Advanced Studies (SOKENDAI), Myodaiji, Okazaki 444-8787, Japan
| | - Daisuke Yamaki
- Department of Chemistry, Graduate
School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397,
Japan
| | - Kenichiro Ikemura
- Department of Life
Science and
Picobiology Institute, Graduate
School of Life Science, University of Hyogo, Koto, Kamigori, Ako, Hyogo 678-1297, Japan
| | - Takuya Kurahashi
- Institute for Molecular
Science
and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787,
Japan
- Department of Functional
Molecular
Science, The Graduate University for Advanced Studies (SOKENDAI), Myodaiji, Okazaki 444-8787, Japan
| | - Takashi Ogura
- Department of Life
Science and
Picobiology Institute, Graduate
School of Life Science, University of Hyogo, Koto, Kamigori, Ako, Hyogo 678-1297, Japan
| | - Masahiko Hada
- Department of Chemistry, Graduate
School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397,
Japan
| | - Hiroshi Fujii
- Institute for Molecular
Science
and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787,
Japan
- Department of Functional
Molecular
Science, The Graduate University for Advanced Studies (SOKENDAI), Myodaiji, Okazaki 444-8787, Japan
| |
Collapse
|
22
|
Qi MH, Liu GF. Synthesis, electrochemical, photovoltaic, and photo-physical properties on the lanthanide(III) complexes of acetylacetonate and meso-tetraalkyltetrabenzoporphyrin with electric-field induction. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424604000520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lanthanide(III) complexes with acetylacetonate and meso-tetraalkyltetrabenzoporphyrin (TATBP) having the general formula Ln ( TATBP )acac (where Ln = Tb , Dy , Ho , Er , Tm , Yb ; A = C 12 H 25; Hacac = acetylacetone) are reported. These compexes have been studied by elemental analyses, ultraviolet visible spectra, infrared spectra, molar conductance, 1 H NMR spectra, cyclic voltammetry, surface photovoltage spectroscopy (SPS), and luminescence spectroscopy. The infrared spectral bands of the ligand and complexes were assigned. In dimethylformamide (DMF), 0.1 M tetrabutylammonium perchlorate (TBAP), the synthesized TATBP exhibit two one-electron reversible redox reactions, and Ln(TATBP)acac shows three redox reactions respectively, within the accessible potential window of the solvent. The absorption bands of the complexes appear in the range 431-433 (Soret band), 578-580 (Q band) and 627-631 (Q band) nm. The photovoltaic properties and charge transfer process of these compounds were investigated by surface photovoltage spectroscopy (SPS) and electric-field-induced surface photovoltage spectroscopy (EFISPS) techniques, which reveal that the ligand TATBP and the complexes Er(TATBP)acac are p-type semiconductors. The spectral bands of TATBP correspond to π → π* transitions. Quantum yields of the S 1 → S 0 fluorescence are in the region 0.25-0.27 and the fluorescence lifetimes are in the region 0.014-0.022 ms at room temperature. The phosphorescence bands of the complex at 77 K appears 714 nm.
Collapse
Affiliation(s)
- Ming-Hui Qi
- Department of Chemistry, Jilin University, Changchun, 130023, P. R. China
| | - Guo-Fa Liu
- Department of Chemistry, Jilin University, Changchun, 130023, P. R. China
| |
Collapse
|
23
|
Shook RL, Peterson SM, Greaves J, Moore C, Rheingold AL, Borovik A. Catalytic reduction of dioxygen to water with a monomeric manganese complex at room temperature. J Am Chem Soc 2011; 133:5810-7. [PMID: 21425844 PMCID: PMC3381988 DOI: 10.1021/ja106564a] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
There have been numerous efforts to incorporate dioxygen into chemical processes because of its economic and environmental benefits. The conversion of dioxygen to water is one such example, having importance in both biology and fuel cell technology. Metals or metal complexes are usually necessary to promote this type of reaction and several systems have been reported. However, mechanistic insights into this conversion are still lacking, especially the detection of intermediates. Reported herein is the first example of a monomeric manganese(II) complex that can catalytically convert dioxygen to water. The complex contains a tripodal ligand with two urea groups and one carboxyamidopyridyl unit; this ligand creates an intramolecular hydrogen-bonding network within the secondary coordination sphere that aids in the observed chemistry. The manganese(II) complex is five-coordinate with an N(4)O primary coordination sphere; the oxygen donor comes from the deprotonated carboxyamido moiety. Two key intermediates were detected and characterized: a peroxo-manganese(III) species and a hybrid oxo/hydroxo-manganese(III) species (1). The formulation of 1 was based on spectroscopic and analytical data, including an X-ray diffraction analysis. Reactivity studies showed dioxygen was catalytically converted to water in the presence of reductants, such as diphenylhydrazine and hydrazine. Water was confirmed as a product in greater than 90% yield. A mechanism was proposed that is consistent with the spectroscopy and product distribution, in which the carboxyamido group switches between a coordinated ligand and a basic site to scavenge protons produced during the catalytic cycle. These results highlight the importance of incorporating intramolecular functional groups within the secondary coordination sphere of metal-containing catalysts.
Collapse
Affiliation(s)
- Ryan L. Shook
- Department of Chemistry, University of California-Irvine, 1102 Natural Science II, Irvine, CA 92697-2025
| | - Sonja M. Peterson
- Department of Chemistry, University of California-Irvine, 1102 Natural Science II, Irvine, CA 92697-2025
| | - John Greaves
- Department of Chemistry, University of California-Irvine, 1102 Natural Science II, Irvine, CA 92697-2025
| | - Curtis Moore
- Department of Chemistry and Biochemistry, University of California-San Diego, San Diego, 92093-0332
| | - Arnold L. Rheingold
- Department of Chemistry and Biochemistry, University of California-San Diego, San Diego, 92093-0332
| | - A.S. Borovik
- Department of Chemistry, University of California-Irvine, 1102 Natural Science II, Irvine, CA 92697-2025
| |
Collapse
|
24
|
|
25
|
de Visser SP, Latifi R, Tahsini L, Nam W. The Axial Ligand Effect on Aliphatic and Aromatic Hydroxylation by Non-heme Iron(IV)-oxo Biomimetic Complexes. Chem Asian J 2010; 6:493-504. [DOI: 10.1002/asia.201000586] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Indexed: 11/05/2022]
|
26
|
Yadav JS, Antony A, George J, Subba Reddy BV. Recent Developments in Indium Metal and Its Salts in Organic Synthesis. European J Org Chem 2010. [DOI: 10.1002/ejoc.200900895] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- J. S. Yadav
- Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500007, India, Fax: +91‐40‐7160512
| | - Aneesh Antony
- Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500007, India, Fax: +91‐40‐7160512
| | - Jimil George
- Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500007, India, Fax: +91‐40‐7160512
| | - Basi V. Subba Reddy
- Division of Organic Chemistry, Indian Institute of Chemical Technology, Hyderabad 500007, India, Fax: +91‐40‐7160512
| |
Collapse
|
27
|
Denisov IG, Mak PJ, Makris TM, Sligar SG, Kincaid JR. Resonance Raman characterization of the peroxo and hydroperoxo intermediates in cytochrome P450. J Phys Chem A 2009; 112:13172-9. [PMID: 18630867 DOI: 10.1021/jp8017875] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Resonance Raman (RR) studies of intermediates generated by cryoreduction of the oxyferrous complex of the D251N mutant of cytochrome P450(cam) (CYP101) are reported. Owing to the fact that proton delivery to the active site is hindered in this mutant, the unprotonated peroxo-ferric intermediate is observed as the primary species after radiolytic reduction of the oxy-complex in frozen solutions at 77 K. In as much as previous EPR and ENDOR studies have shown that annealing of this species to approximately 180 K results in protonation of the distal oxygen atom to form the hydroperoxo intermediate, this system has been exploited to permit direct RR interrogation of the changes in the Fe-O and O-O bonds caused by the reduction and subsequent protonation. Our results show that the nu(O-O) mode decreases from a superoxo-like frequency near approximately 1130 cm(-1) to 792 cm(-1) upon reduction. The latter frequency, as well as its lack of sensitivity to H/D exchange, is consistent with heme-bound peroxide formulation. This species also exhibits a nu(Fe-O) mode, the 553 cm(-1) frequency of which is higher than that observed for the nonreduced oxy P450 precursor (537 cm(-1)), implying a strengthened Fe-O linkage upon reduction. Upon subsequent protonation, the resulting Fe-O-OH fragment exhibits a lowered nu(O-O) mode at 774 cm(-1), whereas the nu(Fe-O) increases to 564 cm(-1). Both modes exhibit a downshift upon H/D exchange, as expected for a hydroperoxo-ferric formulation. These experimental RR data are compared with those previously acquired for the wild-type protein, and the shifts observed upon reduction and subsequent protonation are discussed with reference to theoretical predictions.
Collapse
Affiliation(s)
- Ilia G Denisov
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801, USA
| | | | | | | | | |
Collapse
|
28
|
Reddy JJ, Ohta T, Naruta Y. Synthesis and characterization of a new prostaglandin H synthase model. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.02.145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
29
|
Mukherjee J, Lucas RL, Zart MK, Powell DR, Day VW, Borovik AS. Synthesis, structure, and physical properties for a series of monomeric iron(III) hydroxo complexes with varying hydrogen-bond networks. Inorg Chem 2008; 47:5780-6. [PMID: 18498155 PMCID: PMC3876470 DOI: 10.1021/ic800048e] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mononuclear iron(III) complexes with terminal hydroxo ligands are proposed to be important species in several metalloproteins, but they have been difficult to isolate in synthetic systems. Using a series of amidate/ureido tripodal ligands, we have prepared and characterized monomeric Fe (III)OH complexes with similar trigonal-bipyramidal primary coordination spheres. Three anionic nitrogen donors define the trigonal plane, and the hydroxo oxygen atom is trans to an apical amine nitrogen atom. The complexes have varied secondary coordination spheres that are defined by intramolecular hydrogen bonds between the Fe (III)OH unit and the urea NH groups. Structural trends were observed between the number of hydrogen bonds and the Fe-O hydroxo bond distances: the more intramolecular hydrogen bonds there were, the longer the Fe-O bond became. Spectroscopic trends were also found, including an increase in the energy of the O-H vibrations with a decrease in the number of hydrogen bonds. However, the Fe (III/II) reduction potentials were constant throughout the series ( approximately 2.0 V vs [Cp 2Fe] (0/+1)), which is ascribed to a balancing of the primary and secondary coordination-sphere effects.
Collapse
|
30
|
|
31
|
Nakazawa J, Hagiwara J, Mizuki M, Shimazaki Y, Tani F, Naruta Y. Size-selective and reversible encapsulation of single small hydrocarbon molecules by a cavitand-porphyrin species. Angew Chem Int Ed Engl 2006; 44:3744-6. [PMID: 15880696 DOI: 10.1002/anie.200500732] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jun Nakazawa
- Institute for Materials Chemistry and Engineering, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan
| | | | | | | | | | | |
Collapse
|
32
|
Franke A, Hessenauer-Ilicheva N, Meyer D, Stochel G, Woggon WD, van Eldik R. Thermodynamic and Kinetic Studies on the Binding of Nitric Oxide to a New Enzyme Mimic of Cytochrome P450. J Am Chem Soc 2006; 128:13611-24. [PMID: 17031976 DOI: 10.1021/ja060650o] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new model for the P450 enzyme carrying a SO(3)(-) ligand coordinated to iron(III) (complex 2) reversibly binds NO to yield the nitrosyl adduct. The rate constant for NO binding to 2 in toluene is of the same order of magnitude as that found for the nitrosylation of the native, substrate-bound form of P450(cam) (E.S-P450(cam)). Large and negative activation entropy and activation volume values for the binding of NO to complex 2 support a mechanism that is dominated by bond formation with concomitant iron spin change from S = (5)/(2) to S = 0, as proposed for the reaction between NO and E.S-P450(cam). In contrast, the dissociation of NO from 2(NO) was found to be several orders of magnitude faster than the corresponding reaction for the E.S-P450(cam)/NO system. In a coordinating solvent such as methanol, the alcohol coordinates to iron(III) of 2 at the distal position, generating a six-coordinate, high-spin species 5. The reaction of NO with 5 in methanol was found to be much slower in comparison to the nitrosylation reaction of 2 in toluene. This behavior can be explained in terms of a mechanism in which methanol must be displaced during Fe-NO bond formation. The thermodynamic and kinetic data for NO binding to the new model complexes of P450 (2 and 5) are discussed in reference to earlier results obtained for closely related nitrosylation reactions of cytochrome P450(cam) (in the presence and in the absence of the substrate) and a thiolate-ligated iron(III) model complex.
Collapse
Affiliation(s)
- Alicja Franke
- Institute for Inorganic Chemistry, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany
| | | | | | | | | | | |
Collapse
|
33
|
Nakazawa J, Mizuki M, Hagiwara J, Shimazaki Y, Tani F, Naruta Y. Syntheses, Crystal Structures, and Single Small Molecule Encapsulation Properties of Cavitand-Porphyrins. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2006. [DOI: 10.1246/bcsj.79.1431] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
34
|
Metteau L, Parsons S, Mareque-Rivas JC. Hydrogen Bonding Cavities Regulating Redox Behavior and Binding of Metal-Bound Ligands. Inorg Chem 2006; 45:6601-3. [PMID: 16903713 DOI: 10.1021/ic0612193] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Binding of 3,5-di-tert-butyl-1,2-benzochatechol (H2DTBC) at Zn(II) complexes of a tetradentate, tripodal ligand L is significantly enhanced (36-4.6 x 10(4) fold), and its reduction potential shifted (90-270 mV) to more positive values by introducing one to three amino hydrogen bond donors. The structure of one of the [(L)Zn(DTBC)] complexes is reported and shows intramolecular N-H...O hydrogen bonding between the ligand-based amino group and the Zn(II)-bound chatecholate, which provides an explanation for the observed behavior.
Collapse
Affiliation(s)
- Laurent Metteau
- School of Chemistry, The University of Edinburgh, Edinburgh EH9 3JJ, U.K
| | | | | |
Collapse
|
35
|
Mareque Rivas JC, Hinchley SL, Metteau L, Parsons S. The strength of hydrogen bonding to metal-bound ligands can contribute to changes in the redox behaviour of metal centres. Dalton Trans 2006:2316-22. [PMID: 16688319 DOI: 10.1039/b516234c] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of nine tripodal tetradentate ligands based on tris(pyridyl-2-methyl)amine TPA with hydrogen bond donors R in one, two and three of the pyridine 6-positions (R = NH2 amino, L(Am-1,2,3); NHCH2(t)Bu neopentylamino, L(Np-1,2,3); NHCO(t)Bu pivaloylamido, L(Piv-1,2,3)) and TPA are used to investigate the effect of different hydrogen bonding microenvironments on electrochemical properties of their LCuCl complexes. The hydrogen bond donors are rigidly preorganised and suitably oriented for intramolecular N-H...Cl-Cu hydrogen bonds. Cyclic voltammetry studies show that the reduction potential of the Cu(II)/Cu(I) couple as a function of the ligand follows the order TPA < L(Am-n) < or approximately L(Np-n) < L(Piv-n), and that the magnitude of the effect increases with the number of hydrogen bonding groups. These trends could be explained in terms of the steric and electronic effects exerted by these groups stabilising the Cu(I) oxidation state. In fact, the X-ray structure of the air-stable [(L(Piv-3))Cu(I)Cl] complex is reported and shows elongated Cu-N and Cu-Cl bonds, presumably due to the combination of steric and electron withdrawing effects exerted by the three pivaloylamido groups. We reasoned that the strength of hydrogen bonding in the Cu(I) and Cu(II) oxidation states could differ and therefore contribute also to the aforementioned redox changes; this hypothesis is tested using IR and NMR spectroscopy. IR studies of the [(L(Piv-1,2,3))Cu(I)Cl] and [(L(Piv-1,2,3))Cu(II)Cl]+ complexes in acetonitrile show that the intramolecular N-H...Cl-Cu hydrogen bonding weakens in the order L(Piv-1) > L(Piv-2) > L(Piv-3), and that it is stronger in the Cu(I) complexes. The 1H NMR spectra of the [(L(Piv1,2,3))Cu(I)Cl] complexes are in complete agreement with the IR data, and reveal that the stability of the Cu(I) complexes to oxidation in air increases in the order L(Piv-1) < L(Piv-2) << L(Piv-3). The hydrogen bonds in the Cu(I) complexes are stronger because of the higher electron density on the Cl ligand, when compared to the Cu(II) complexes. This is consistent with ab initio MP2 calculations performed on the complexes [(L(Piv-3))Cu(I)Cl] and [(L(Piv-3))Cu(II)Cl]+. Thus, the electron density of a metal-bound ligand acting as hydrogen bond acceptor is revealed as the major factor in determining the strength of the hydrogen bonds formed. From the IR data the energies of the N-H...Cl-Cu hydrogen bonds is estimated, as is the contribution of changes in hydrogen bond strength with the oxidation state of the copper centre and number of interactions to stabilising the Cu(I) state. Some of the implications of this result in dioxygen activation chemistry are discussed.
Collapse
Affiliation(s)
- Juan C Mareque Rivas
- School of Chemistry, University of Edinburgh, Joseph Black Building, King's Buildings, West Mains Road, Edinburgh, UK EH9 3JJ.
| | | | | | | |
Collapse
|
36
|
Nakazawa J, Hagiwara J, Mizuki M, Shimazaki Y, Tani F, Naruta Y. Size-Selective and Reversible Encapsulation of Single Small Hydrocarbon Molecules by a Cavitand-Porphyrin Species. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200500732] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
37
|
Synthesis, characterization, and catalytic oxygenation activity of dinuclear iron(III) complex supported by binaphthol-containing chiral ligand. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.molcata.2004.08.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
38
|
Ohkawa H, Arai S, Takeoka S, Shibue T, Nishide H. A Duplex of Tetra(2-pyridyl)porphyrin and Tetrahydroxylcalix[4]arene. CHEM LETT 2003. [DOI: 10.1246/cl.2003.1052] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
39
|
Shul’pin GB. Metal-catalyzed hydrocarbon oxygenations in solutions: the dramatic role of additives: a review. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1381-1169(02)00196-6] [Citation(s) in RCA: 416] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
40
|
Nakayama S, Tani F, Matsu-ura M, Naruta Y. Cobalt “Single-coronet” Porphyrin Bearing Hydroxyl Groups in Its O2Binding Site as a New Model for Myoglobin and Hemoglobin: Observation of Unusually Low Frequency of ν(O-O) in Resonance Raman Spectrum. CHEM LETT 2002. [DOI: 10.1246/cl.2002.496] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
41
|
Matsu-Ura M, Tani F, Naruta Y. Formation and characterization of carbon monoxide adducts of iron "twin coronet" porphyrins. Extremely low CO affinity and a strong negative polar effect on bound CO. J Am Chem Soc 2002; 124:1941-50. [PMID: 11866607 DOI: 10.1021/ja011963g] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The carbon monoxide (CO) adducts of iron "twin coronet" porphyrins (TCPs) are characterized by UV-vis, resonance Raman (RR), IR, and 13C NMR spectroscopies. A superstructured porphyrin, designated as TCP, was used as a common framework for the four different types of iron complexes. TCP bears two binaphthalene bridges on each side and creates two hydrophobic pockets surrounded by the bulky aromatic rings. In the CO-binding cavities, the hydroxyl groups are oriented toward the center above the heme. The iron complexes investigated are as follows: TCP (which is without a covalently linked axial ligand), TCP-PY (which has a linked pyridine ligand), and TCP-TB and TCP-TG (both of which have a linked thiolate ligand). These complexes were synthesized as ferric forms and identified by the various spectroscopic methods. The UV-vis spectra of TCP-CO and TCP-PY-CO exhibit lambda(max) at 432, 546 and 428, 541 nm, respectively. On the other hand, the CO adducts of TCP-TB and TCP-TG show typical hyperporphyrin spectra for a thiolate-ligated iron(II) porphyrin-CO complex. In the RR spectra, the nu(Fe-CO) bands were observed at 506, 489 cm(-1) (TCP), 465 cm(-1) (TCP-PY), 458, 437 cm(-1) (TCP-TG) and 429 cm(-1) (TCP-TB). Compared with the reported nu(Fe-CO) frequencies of hemoproteins and their model systems, these observed values are unusually low. Further, abnormally high nu(C-O) bands are observed at 1990 cm(-1) (TCP-CO) and 2008 cm(-1) (TCP-PY-CO) in IR spectra. The lower nu(Fe-CO) and the higher nu(C-O) frequencies can be ascribed to the strong negative polar effect caused by the vicinal hydroxyl groups in the cavity. This prediction is further supported by the observation of significant 13C shieldings exhibited by TCP-CO (delta = 202.6 ppm) and TCP-PY-CO (delta = 202.3 ppm), in comparison to hemoproteins and other heme models. The CO affinity of TCP-PY (P1/2CO = 0.017 Torr at 25 C) is unusually lower than other heme models. The unique behavior of these CO adducts is discussed in context of the TCP structures.
Collapse
Affiliation(s)
- Mikiya Matsu-Ura
- Institute for Fundamental Research of Organic Chemistry, Kyushu University, Higashi-ku, Fukuoka 812-8581, Japan
| | | | | |
Collapse
|
42
|
|
43
|
Naruta Y, Goto MO, Tawara T, Tani F. Highly Terminal-Selective Epoxidation of Linolenic Acid with an Amphiphilic Iron Porphyrin Catalyst Casted in Bilayer Membranes. CHEM LETT 2002. [DOI: 10.1246/cl.2002.162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
44
|
|
45
|
Ost TW, Munro AW, Mowat CG, Taylor PR, Pesseguiero A, Fulco AJ, Cho AK, Cheesman MA, Walkinshaw MD, Chapman SK. Structural and spectroscopic analysis of the F393H mutant of flavocytochrome P450 BM3. Biochemistry 2001; 40:13430-8. [PMID: 11695889 DOI: 10.1021/bi010717e] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the preceding paper in this issue [Ost, T. W. B., Miles, C. S., Munro, A. W., Murdoch, J., Reid, G. A., and Chapman, S. K. (2001) Biochemistry 40, 13421-13429], we have established that the primary role of the phylogenetically conserved phenylalanine in flavocytochrome P450 BM3 (F393) is to control the thermodynamic properties of the heme iron, so as to optimize electron-transfer both to the iron (from the flavin redox partner) and onto molecular oxygen. In this paper, we report a detailed study of the F393H mutant enzyme, designed to probe the structural, spectroscopic, and metabolic profile of the enzyme in an attempt to identify the factors responsible for causing the changes. The heme domain structure of the F393H mutant has been solved to 2.0 A resolution and demonstrates that the histidine replaces the phenylalanine in almost exactly the same conformation. A solvent water molecule is hydrogen bonded to the histidine, but there appears to be little other gross alteration in the environment of the heme. The F393H mutant displays an identical ferric EPR spectrum to wild-type, implying that the degree of splitting of the iron d orbitals is unaffected by the substitution, however, the overall energy of the d-orbitals have changed relative to each other. Magnetic CD studies show that the near-IR transition, diagnostic of heme ligation state, is red-shifted by 40 nm in F393H relative to wild-type P450 BM3, probably reflecting alteration in the strength of the iron-cysteinate bond. Studies of the catalytic turnover of fatty acid (myristate) confirms NADPH oxidation is tightly coupled to fatty acid oxidation in F393H, with a product profile very similar to wild-type. The results indicate that gross conformational changes do not account for the perturbations in the electronic features of the P450 BM3 heme system and that the structural environment on the proximal side of the P450 heme must be conformationally conserved in order to optimize catalytic function.
Collapse
Affiliation(s)
- T W Ost
- Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK.
| | | | | | | | | | | | | | | | | | | |
Collapse
|