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Molecules (Basel, Switzerland) Sep 2022This article gives an overview of the research activity of the LAC2 team at LCC developed at Castres in the field of sustainable chemistry with an emphasis on the... (Review)
Review
This article gives an overview of the research activity of the LAC2 team at LCC developed at Castres in the field of sustainable chemistry with an emphasis on the collaboration with a research team from the University of Zagreb, Faculty of Science, Croatia. The work is situated within the context of sustainable chemistry for the development of catalytic processes. Those processes imply molecular complexes containing oxido-molybdenum, -vanadium, -tungsten or simple polyoxometalates (POMs) as catalysts for organic solvent-free epoxidation. The studies considered first the influence of the nature of complexes (and related ligands) on the reactivity (assessing mechanisms through DFT calculations) with model substrates. From those model processes, the work has been enlarged to the valorization of biomass resources. A part concerns the activity on vanadium chemistry and the final part concerns the use of POMs as catalysts, from molecular to grafted catalysts, (ep)oxidizing substrates from fossil and biomass resources.
Topics: Catalysis; Molybdenum; Oxidation-Reduction; Tungsten; Vanadium
PubMed: 36144747
DOI: 10.3390/molecules27186011 -
Journal of Inorganic Biochemistry Oct 2022Resonance Raman spectroscopy (rR) is a powerful spectroscopic probe that is widely used for studying the geometric and electronic structure of metalloproteins. In this... (Review)
Review
Resonance Raman spectroscopy (rR) is a powerful spectroscopic probe that is widely used for studying the geometric and electronic structure of metalloproteins. In this focused review, we detail how resonance Raman spectroscopy has contributed to a greater understanding of electronic structure, geometric structure, and the reaction mechanisms of pyranopterin molybdenum enzymes. The review focuses on the enzymes sulfite oxidase (SO), dimethyl sulfoxide reductase (DMSOR), xanthine oxidase (XO), and carbon monoxide dehydrogenase. Specifically, we highlight how Mo-O, Mo-S, Mo-S, and dithiolene CC vibrational modes, isotope and heavy atom perturbations, resonance enhancement, and associated Raman studies of small molecule analogs have provided detailed insight into the nature of these metalloenzyme active sites.
Topics: Coenzymes; Metalloproteins; Models, Molecular; Molybdenum; Pterins; Spectrum Analysis, Raman
PubMed: 35932756
DOI: 10.1016/j.jinorgbio.2022.111907 -
Molecules (Basel, Switzerland) Jun 2022Molybdenum cofactor (Moco) biosynthesis requires iron, copper, and ATP. The Moco-containing enzyme sulfite oxidase catalyzes terminal oxidation in oxidative cysteine... (Review)
Review
Molybdenum cofactor (Moco) biosynthesis requires iron, copper, and ATP. The Moco-containing enzyme sulfite oxidase catalyzes terminal oxidation in oxidative cysteine catabolism, and another Moco-containing enzyme, xanthine dehydrogenase, functions in purine catabolism. Thus, molybdenum enzymes participate in metabolic pathways that are essential for cellular detoxication and energy dynamics. Studies of the Moco biosynthetic enzymes MoaE (in the Ada2a-containing (ATAC) histone acetyltransferase complex) and MOCS2 have revealed that Moco biosynthesis and molybdenum enzymes align to regulate signaling and metabolism via control of transcription and translation. Disruption of these functions is involved in the onset of dementia and neurodegenerative disease. This review provides an overview of the roles of MoaE and MOCS2 in normal cellular processes and neurodegenerative disease, as well as directions for future research.
Topics: Coenzymes; Humans; Metalloproteins; Molybdenum; Molybdenum Cofactors; Neurodegenerative Diseases; Sulfite Oxidase; Sulfurtransferases; Xanthine Dehydrogenase
PubMed: 35744859
DOI: 10.3390/molecules27123733 -
Biochimica Et Biophysica Acta 2013Molybdenum cofactor (Moco) biosynthesis is an ancient, ubiquitous, and highly conserved pathway leading to the biochemical activation of molybdenum. Moco is the... (Review)
Review
Molybdenum cofactor (Moco) biosynthesis is an ancient, ubiquitous, and highly conserved pathway leading to the biochemical activation of molybdenum. Moco is the essential component of a group of redox enzymes, which are diverse in terms of their phylogenetic distribution and their architectures, both at the overall level and in their catalytic geometry. A wide variety of transformations are catalyzed by these enzymes at carbon, sulfur and nitrogen atoms, which include the transfer of an oxo group or two electrons to or from the substrate. More than 50 molybdoenzymes were identified in bacteria to date. In molybdoenzymes Mo is coordinated to a dithiolene group on the 6-alkyl side chain of a pterin called molybdopterin (MPT). The biosynthesis of Moco can be divided into four general steps in bacteria: 1) formation of the cyclic pyranopterin monophosphate, 2) formation of MPT, 3) insertion of molybdenum into molybdopterin to form Moco, and 4) additional modification of Moco with the attachment of GMP or CMP to the phosphate group of MPT, forming the dinucleotide variant of Moco. This review will focus on molybdoenzymes, the biosynthesis of Moco, and its incorporation into specific target proteins focusing on Escherichia coli. This article is part of a Special Issue entitled: Metals in Bioenergetics and Biomimetics Systems.
Topics: Coenzymes; Enzymes; Escherichia coli; Metalloproteins; Molybdenum; Molybdenum Cofactors; Pteridines
PubMed: 23201473
DOI: 10.1016/j.bbabio.2012.11.007 -
Molecules (Basel, Switzerland) Dec 2023Only a single enzyme system-nitrogenase-carries out the conversion of atmospheric N into bioavailable ammonium, an essential prerequisite for all organismic life. The... (Review)
Review
Only a single enzyme system-nitrogenase-carries out the conversion of atmospheric N into bioavailable ammonium, an essential prerequisite for all organismic life. The reduction of this inert substrate at ambient conditions poses unique catalytic challenges that strain our mechanistic understanding even after decades of intense research. Structural biology has added its part to this greater tapestry, and in this review, I provide a personal (and highly biased) summary of the parts of the story to which I had the privilege to contribute. It focuses on the crystallographic analysis of the three isoforms of nitrogenases at high resolution and the binding of ligands and inhibitors to the active-site cofactors of the enzyme. In conjunction with the wealth of available biochemical, biophysical, and spectroscopic data on the protein, this has led us to a mechanistic hypothesis based on an elementary mechanism of repetitive hydride formation and insertion.
Topics: Nitrogenase; Nitrogen Fixation; Catalysis; Molybdenum; Nitrogen
PubMed: 38138449
DOI: 10.3390/molecules28247959 -
Metal Ions in Life Sciences Mar 2020The last 20 years have seen a dramatic increase in our mechanistic understanding of the reactions catalyzed by pyranopterin Mo and W enzymes. These enzymes possess a...
The last 20 years have seen a dramatic increase in our mechanistic understanding of the reactions catalyzed by pyranopterin Mo and W enzymes. These enzymes possess a unique cofactor (Moco) that contains a novel ligand in bioinorganic chemistry, the pyranopterin ene-1,2-dithiolate. A synopsis of Moco biosynthesis and structure is presented, along with our current understanding of the role Moco plays in enzymatic catalysis. Oxygen atom transfer (OAT) reactivity is discussed in terms of breaking strong metal-oxo bonds and the mechanism of OAT catalyzed by enzymes of the sulfite oxidase (SO) family that possess dioxo Mo(VI) active sites. OAT reactivity is also discussed in members of the dimethyl sulfoxide (DMSO) reductase family, which possess des-oxo Mo(IV) sites. Finally, we reveal what is known about hydride transfer reactivity in xanthine oxidase (XO) family enzymes and the formate dehydrogenases. The formal hydride transfer reactivity catalyzed by xanthine oxidase family enzymes is complex and cleaves substrate C-H bonds using a mechanism that is distinct from monooxygenases. The chapter primarily highlights developments in the field that have occurred since ~2000, which have contributed to our collective structural and mechanistic understanding of the three canonical pyranopterin Mo enzymes families: XO, SO, and DMSO reductase.
Topics: Biocatalysis; Molybdenum; Sulfite Oxidase; Tungsten
PubMed: 32851830
DOI: 10.1515/9783110589757-015 -
Molecules (Basel, Switzerland) Feb 2023A personal perspective is provided regarding the work in several laboratories, including the author's, that has established the reaction mechanism of xanthine oxidase... (Review)
Review
A personal perspective is provided regarding the work in several laboratories, including the author's, that has established the reaction mechanism of xanthine oxidase and related enzymes.
Topics: Xanthine Oxidase; Electron Spin Resonance Spectroscopy; Molybdenum; Xanthine Dehydrogenase
PubMed: 36838909
DOI: 10.3390/molecules28041921 -
Molecules (Basel, Switzerland) Aug 2022The transition element molybdenum (Mo) is an essential micronutrient for plants, animals, and microorganisms, where it forms part of the active center of Mo enzymes. To... (Review)
Review
The transition element molybdenum (Mo) is an essential micronutrient for plants, animals, and microorganisms, where it forms part of the active center of Mo enzymes. To gain biological activity in the cell, Mo has to be complexed by a pterin scaffold to form the molybdenum cofactor (Moco). Mo enzymes and Moco are found in all kingdoms of life, where they perform vital transformations in the metabolism of nitrogen, sulfur, and carbon compounds. In this review, I recall the history of Moco in a personal view, starting with the genetics of Moco in the 1960s and 1970s, followed by Moco biochemistry and the description of its chemical structure in the 1980s. When I review the elucidation of Moco biosynthesis in the 1990s and the early 2000s, I do it mainly for eukaryotes, as I worked with plants, human cells, and filamentous fungi. Finally, I briefly touch upon human Moco deficiency and whether there is life without Moco.
Topics: Animals; Coenzymes; Eukaryota; Humans; Metalloproteins; Molybdenum; Molybdenum Cofactors; Plants; Pterins
PubMed: 35956883
DOI: 10.3390/molecules27154934 -
Molecules (Basel, Switzerland) Jul 2023Mo/W-containing formate dehydrogenases (FDH) catalyzes the reversible oxidation of formate to carbon dioxide at their molybdenum or tungsten active sites. The... (Review)
Review
Mo/W-containing formate dehydrogenases (FDH) catalyzes the reversible oxidation of formate to carbon dioxide at their molybdenum or tungsten active sites. The metal-containing FDHs are members of the dimethylsulfoxide reductase family of mononuclear molybdenum cofactor (Moco)- or tungsten cofactor (Wco)-containing enzymes. In these enzymes, the active site in the oxidized state comprises a Mo or W atom present in the bis-Moco, which is coordinated by the two dithiolene groups from the two MGD moieties, a protein-derived SeCys or Cys, and a sixth ligand that is now accepted as being a sulfido group. SeCys-containing enzymes have a generally higher turnover number than Cys-containing enzymes. The analogous chemical properties of W and Mo, the similar active sites of W- and Mo-containing enzymes, and the fact that W can replace Mo in some enzymes have led to the conclusion that Mo- and W-containing FDHs have the same reaction mechanism. Details of the catalytic mechanism of metal-containing formate dehydrogenases are still not completely understood and have been discussed here.
Topics: Formate Dehydrogenases; Oxidation-Reduction; Metalloproteins; Molybdenum; Catalytic Domain; Pteridines; Coenzymes
PubMed: 37513211
DOI: 10.3390/molecules28145338 -
Molecules (Basel, Switzerland) Nov 2023The pyranopterin dithiolene ligand is remarkable in terms of its geometric and electronic structure and is uniquely found in mononuclear molybdenum and tungsten enzymes.... (Review)
Review
The pyranopterin dithiolene ligand is remarkable in terms of its geometric and electronic structure and is uniquely found in mononuclear molybdenum and tungsten enzymes. The pyranopterin dithiolene is found coordinated to the metal ion, deeply buried within the protein, and non-covalently attached to the protein via an extensive hydrogen bonding network that is enzyme-specific. However, the function of pyranopterin dithiolene in enzymatic catalysis has been difficult to determine. This focused account aims to provide an overview of what has been learned from the study of pyranopterin dithiolene model complexes of molybdenum and how these results relate to the enzyme systems. This work begins with a summary of what is known about the pyranopterin dithiolene ligand in the enzymes. We then introduce the development of inorganic small molecule complexes that model aspects of a coordinated pyranopterin dithiolene and discuss the results of detailed physical studies of the models by electronic absorption, resonance Raman, X-ray absorption and NMR spectroscopies, cyclic voltammetry, X-ray crystallography, and chemical reactivity.
Topics: Models, Molecular; Molybdenum; Ligands; Metalloproteins; Catalysis; Coenzymes
PubMed: 38005178
DOI: 10.3390/molecules28227456