Copper-Promoted Functionalization of Organic Molecules: from Biologically Relevant Cu/O₂ Model Systems to Organometallic Transformations

Chemical Reviews, Journal Year: 2019, Volume and Issue: 119(4), P. 2954 - 3031

Published: Jan. 30, 2019

Copper is one of the most abundant and less toxic transition metals. Nature takes advantage bioavailability rich redox chemistry Cu to carry out oxygenase oxidase organic transformations using O2 (or H2O2) as oxidant. Inspired by reactivity these Cu-dependent metalloenzymes, chemists have developed synthetic protocols functionalize molecules under enviormentally benign conditions. also promotes other usually catalyzed 4d 5d metals (Pd, Pt, Rh, etc.) such nitrene insertions or C–C C–heteroatom coupling reactions. In this review, we summarized relevant research in which copper catalyzes functionalization molecules, including biological catalysis, bioinspired model systems, organometallic reactivity. The reaction mechanisms processes take place are discussed detail.

Language: Английский

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Activation of dioxygen by copper metalloproteins and insights from model complexes

JBIC Journal of Biological Inorganic Chemistry, Journal Year: 2016, Volume and Issue: 22(2-3), P. 253 - 288

Published: Dec. 5, 2016

Language: Английский

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Near‐Infrared Fluorescent Probe with New Recognition Moiety for Specific Detection of Tyrosinase Activity: Design, Synthesis, and Application in Living Cells and Zebrafish

Angewandte Chemie International Edition, Journal Year: 2016, Volume and Issue: 55(47), P. 14728 - 14732

Published: Oct. 24, 2016

Abstract Fluorescence imaging of tyrosinase (a cancer biomarker) in living organisms is great importance for biological studies. However, selective detection remains a challenge because current fluorescent probes that contain the 4‐hydroxyphenyl moiety show similar fluorescence responses to both and some reactive oxygen species (ROS), thereby suffering from ROS interference. Herein, new tyrosinase‐recognition 3‐hydroxybenzyloxy moiety, which exhibits distinct ROS, proposed. Using recognition we develop near‐infrared probe activity, effectively eliminates interference ROS. The high specificity was demonstrated by detecting endogenous activity live cells zebrafish further validated an enzyme‐linked immunosorbent assay. expected be useful accurate complex biosystems.

Language: Английский

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Homogeneous Oxygenase Catalysis

Chemical Reviews, Journal Year: 2018, Volume and Issue: 118(10), P. 4912 - 4945

Published: April 9, 2018

Oxygenases-catalyzed reductive activation of molecular oxygen and incorporation O atoms into an organic molecule is undoubtedly one the most attractive research areas. Typically, these oxygenation reactions proceed with high selectivity reactivity, which seldom found in its "biomimetic" chemocatalytic counterparts. Furthermore, enzymatic can avoid undesired overoxidation, frequently observed (industrial) chemical transformation. Therefore, it not surprising that tremendous attention has been paid to oxygenation. Their application synthesis steadily growing over years. The goal present Review provide a handy reference for chemists interested using homogeneous oxygenase catalysis those discovering new types biomimetic oxidations oxygenations dioxygen. In this Review, we will review recent advances reveal great achievements potentials field.

Language: Английский

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The unravelling of the complex pattern of tyrosinase inhibition

Scientific Reports, Journal Year: 2016, Volume and Issue: 6(1)

Published: Oct. 11, 2016

Abstract Tyrosinases are responsible for melanin formation in all life domains. Tyrosinase inhibitors used the prevention of severe skin diseases, skin-whitening creams and to avoid fruit browning, however continued use many such is considered unsafe. In this study we provide conclusive evidence inhibition mechanism two well studied tyrosinase inhibitors, KA (kojic acid) HQ (hydroquinone), which extensively hyperpigmentation treatment. reported literature with contradicting mechanisms, while described as both a inhibitor substrate. By visualization active site TyrBm crystals, together molecular modeling, binding constant analysis kinetic experiments, have elucidated their mechanisms inhibition, was ambiguous inhibitors. We confirm that acts mixed inhibitor, can act substrate an inhibitor.

Language: Английский

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Immunological properties of oxygen-transport proteins: hemoglobin, hemocyanin and hemerythrin

Cellular and Molecular Life Sciences, Journal Year: 2016, Volume and Issue: 74(2), P. 293 - 317

Published: Aug. 12, 2016

It is now well documented that peptides with enhanced or alternative functionality (termed cryptides) can be liberated from larger, and sometimes inactive, proteins. A primary example of this phenomenon the oxygen-transport protein hemoglobin. Aside respiration, hemoglobin hemoglobin-derived have been associated immune modulation, hematopoiesis, signal transduction microbicidal activities in metazoans. Likewise, functional equivalents to invertebrates, namely hemocyanin hemerythrin, act as potent effectors under certain physiological conditions. The purpose review evaluate true extent dynamics innate immunity, impress upon reader multi-functionality these ancient proteins on basis their structures. In context, erythrocyte–pathogen antibiosis competences various erythroid cells are compared across diverse taxa.

Language: Английский

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Re‐evaluation of insect melanogenesis research: Views from the dark side

Pigment Cell & Melanoma Research, Journal Year: 2017, Volume and Issue: 30(4), P. 386 - 401

Published: April 5, 2017

Melanins (eumelanin and pheomelanin) are synthesized in insects for several purposes including cuticle sclerotization color patterning, clot formation, organogenesis, innate immunity. Traditional views of insect immunity detail the storage pro-phenoloxidases inside specialized blood cells (hemocytes) their release upon recognition foreign bodies. Activated phenoloxidases convert monophenols into reactive quinones a two-step enzymatic reaction, until recently, mechanism tyrosine hydroxylation remained mystery. Herein, we present our interpretations these enzyme-substrate complexes. The resultant melanins deposited onto surface microbes to immobilize, agglutinate, suffocate them. Phenoloxidase activity melanin production not limited (hemolymph) or cuticle, as recent evidence points more diverse, sophisticated interactions gut with resident symbionts. This review offers insight somewhat neglected areas melanogenesis research, particularly immunity, its role beneficial such pollinators, functional versatility phenoloxidases, limitations common experimental approaches that may impede progress inadvertently.

Language: Английский

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Boosting LPMO-driven lignocellulose degradation by polyphenol oxidase-activated lignin building blocks

Biotechnology for Biofuels, Journal Year: 2017, Volume and Issue: 10(1)

Published: May 10, 2017

Many fungi boost the deconstruction of lignocellulosic plant biomass via oxidation using lytic polysaccharide monooxygenases (LPMOs). The application LPMOs is expected to contribute ecologically friendly conversion into fuels and chemicals. Moreover, applications LPMO-modified cellulose-based products may be envisaged within food or material industry.Here, we show an up 75-fold improvement in LPMO-driven cellulose degradation polyphenol oxidase-activated lignin building blocks. This concerted enzymatic process involves initial monophenols diphenols by oxidase MtPPO7 from Myceliophthora thermophila C1 subsequent MtLPMO9B. Interestingly, shows preference towards lignin-derived methoxylated monophenols. Sequence analysis genomes 336 Ascomycota 208 Basidiomycota reveals a high correlation between AA9 LPMO genes.The activity phenolic compounds distinguishes well-known PPOs, such as tyrosinases, ensures that excellent redox partner LPMOs. genes indicative for importance coupled action different biomass. These results will better understanding both lignocellulose potentially improve exploration eco-friendly routes utilization circular economy.

Language: Английский

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On the Metal Cofactor in the Tyrosinase Family

International Journal of Molecular Sciences, Journal Year: 2018, Volume and Issue: 19(2), P. 633 - 633

Published: Feb. 23, 2018

The production of pigment in mammalian melanocytes requires the contribution at least three melanogenic enzymes, tyrosinase and two other accessory enzymes called tyrosinase-related proteins (Trp1 Trp2), which regulate type amount melanin. last are paralogues to tyrosinase, they appeared late evolution by triplication gene. Tyrosinase is a copper-enzyme, Trp2 zinc-enzyme. Trp1 has been more elusive, direct identification its metal cofactor never achieved. However, due enzymatic activity similarities with it assumed as copper-enzyme. Recently, recombinant human have expressed enough amounts achieve for first time their crystallization. Unexpectedly, found that contains couple Zn(II) active site. This review discusses data about Trps. It points out differences studied models, proposes some possible accounting apparent discrepancies currently appearing. Moreover, proposals flexibility family uptake copper or zinc discussed.

Language: Английский

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Copper–Oxygen Dynamics in the Tyrosinase Mechanism

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 59(32), P. 13385 - 13390

Published: May 1, 2020

Abstract The dinuclear copper enzyme, tyrosinase, activates O 2 to form a (μ‐η :η ‐p eroxido)dicopper(II) species, which hydroxylates phenols catechols. However, the exact mechanism of phenolase reaction in catalytic site tyrosinase is still under debate. We herein report near atomic resolution X‐ray crystal structures active tyrosinases with substrate l ‐tyrosine. At their sites, CuA moved toward ‐tyrosine (CuA1 → CuA2), whose phenol oxygen directly coordinates CuA2, involving movement CuB (CuB1 CuB2). and spectroscopic analyses dioxygen‐bound demonstrated that peroxide ligand rotated, spontaneously weakening its O−O bond. Thus, migration induced by substrate‐binding accompanied rearrangement bound species so as provide one atoms access substrate's ϵ carbon atom.

Language: Английский

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