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Journal of the American Chemical Society Jul 2016Cupredoxins are electron-transfer proteins that have active sites containing a mononuclear Cu center with an unusual trigonal monopyramidal structure (Type 1 Cu). A...
Cupredoxins are electron-transfer proteins that have active sites containing a mononuclear Cu center with an unusual trigonal monopyramidal structure (Type 1 Cu). A single Cu-Scys bond is present within the trigonal plane that is responsible for its unique physical properties. We demonstrate that a cysteine-containing variant of streptavidin (Sav) can serve as a protein host to model the structure and properties of Type 1 Cu sites. A series of artificial Cu proteins are described that rely on Sav and a series of biotinylated synthetic Cu complexes. Optical and EPR measurements highlight the presence of a Cu-Scys bond, and XRD analysis provides structural evidence. We further provide evidence that changes in the linker between the biotin and Cu complex within the synthetic constructs allows for small changes in the placement of Cu centers within Sav that have dramatic effects on the structural and physical properties of the resulting artificial metalloproteins. These findings highlight the utility of the biotin-Sav technology as an approach for simulating active sites of metalloproteins.
Topics: Azurin; Biotinylation; Catalytic Domain; Copper; Cysteine; Ligands; Streptavidin
PubMed: 27385206
DOI: 10.1021/jacs.6b05428 -
International Journal of Molecular... May 2017Metallothionein-3 (MT-3), a member of the mammalian metallothionein (MT) family, is mainly expressed in the central nervous system (CNS). MT-3 possesses a unique... (Review)
Review
Metallothionein-3 (MT-3), a member of the mammalian metallothionein (MT) family, is mainly expressed in the central nervous system (CNS). MT-3 possesses a unique neuronal growth inhibitory activity, and the levels of this intra- and extracellularly occurring metalloprotein are markedly diminished in the brain of patients affected by a number of metal-linked neurodegenerative disorders, including Alzheimer's disease (AD). In these pathologies, the redox cycling of copper, accompanied by the production of reactive oxygen species (ROS), plays a key role in the neuronal toxicity. Although MT-3 shares the metal-thiolate clusters with the well-characterized MT-1 and MT-2, it shows distinct biological, structural and chemical properties. Owing to its anti-oxidant properties and modulator function not only for Zn, but also for Cu in the extra- and intracellular space, MT-3, but not MT-1/MT-2, protects neuronal cells from the toxicity of various Cu(II)-bound amyloids. In recent years, the roles of zinc dynamics and MT-3 function in neurodegeneration are slowly emerging. This short review focuses on the recent developments regarding the chemistry and biology of MT-3.
Topics: Animals; Copper; Humans; Metallothionein; Metallothionein 3; Models, Molecular; Nerve Tissue Proteins; Neurodegenerative Diseases; Neurons; Protein Conformation; Reactive Oxygen Species; Zinc
PubMed: 28538697
DOI: 10.3390/ijms18061117 -
Molecules (Basel, Switzerland) Aug 2022For most organisms molybdenum is essential for life as it is found in the active site of various vitally important molybdenum dependent enzymes (Mo-enzymes). Here,... (Review)
Review
For most organisms molybdenum is essential for life as it is found in the active site of various vitally important molybdenum dependent enzymes (Mo-enzymes). Here, molybdenum is bound to a pterin derivative called molybdopterin (MPT), thus forming the molybdenum cofactor (Moco). Synthesis of Moco involves the consecutive action of numerous enzymatic reaction steps, whereby molybdenum insertases (Mo-insertases) catalyze the final maturation step, i.e., the metal insertion reaction yielding Moco. This final maturation step is subdivided into two partial reactions, each catalyzed by a distinctive Mo-insertase domain. Initially, MPT is adenylylated by the Mo-insertase G-domain, yielding MPT-AMP which is used as substrate by the E-domain. This domain catalyzes the insertion of molybdate into the MPT dithiolene moiety, leading to the formation of Moco-AMP. Finally, the Moco-AMP phosphoanhydride bond is cleaved by the E-domain to liberate Moco from its synthesizing enzyme. Thus formed, Moco is physiologically active and may be incorporated into the different Mo-enzymes or bind to carrier proteins instead.
Topics: Adenosine Monophosphate; Catalytic Domain; Coenzymes; Metalloproteins; Molybdenum; Molybdenum Cofactors; Pterins
PubMed: 36080140
DOI: 10.3390/molecules27175372 -
Nature Communications Oct 2023Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence...
Cytosolic metalloenzymes acquire metals from buffered intracellular pools. How exported metalloenzymes are appropriately metalated is less clear. We provide evidence that TerC family proteins function in metalation of enzymes during export through the general secretion (Sec-dependent) pathway. Bacillus subtilis strains lacking MeeF(YceF) and MeeY(YkoY) have a reduced capacity for protein export and a greatly reduced level of manganese (Mn) in the secreted proteome. MeeF and MeeY copurify with proteins of the general secretory pathway, and in their absence the FtsH membrane protease is essential for viability. MeeF and MeeY are also required for efficient function of the Mn-dependent lipoteichoic acid synthase (LtaS), a membrane-localized enzyme with an extracytoplasmic active site. Thus, MeeF and MeeY, representative of the widely conserved TerC family of membrane transporters, function in the co-translocational metalation of Mn-dependent membrane and extracellular enzymes.
Topics: Bacterial Proteins; Protein Transport; Bacillus subtilis; Secretory Pathway; Metalloproteins
PubMed: 37794032
DOI: 10.1038/s41467-023-41896-1 -
International Journal of Molecular... Aug 2020Hydrogenases are complex metalloenzymes, showing tremendous potential as H-converting redox catalysts for application in light-driven H production, enzymatic fuel cells... (Review)
Review
Hydrogenases are complex metalloenzymes, showing tremendous potential as H-converting redox catalysts for application in light-driven H production, enzymatic fuel cells and H-driven cofactor regeneration. They catalyze the reversible oxidation of hydrogen into protons and electrons. The apo-enzymes are not active unless they are modified by a complicated post-translational maturation process that is responsible for the assembly and incorporation of the complex metal center. The catalytic center is usually easily inactivated by oxidation, and the separation and purification of the active protein is challenging. The understanding of the catalytic mechanisms progresses slowly, since the purification of the enzymes from their native hosts is often difficult, and in some case impossible. Over the past decades, only a limited number of studies report the homologous or heterologous production of high yields of hydrogenase. In this review, we emphasize recent discoveries that have greatly improved our understanding of microbial hydrogenases. We compare various heterologous hydrogenase production systems as well as in vitro hydrogenase maturation systems and discuss their perspectives for enhanced biohydrogen production. Additionally, activities of hydrogenases isolated from either recombinant organisms or in vivo/in vitro maturation approaches were systematically compared, and future perspectives for this research area are discussed.
Topics: Bacterial Proteins; Hydrogenase; Industrial Microbiology; Iron-Sulfur Proteins; Protein Engineering
PubMed: 32824336
DOI: 10.3390/ijms21165890 -
Biomolecules Mar 2020The widespread use of uranium for civilian purposes causes a worldwide concern of its threat to human health due to the long-lived radioactivity of uranium and the high... (Review)
Review
The widespread use of uranium for civilian purposes causes a worldwide concern of its threat to human health due to the long-lived radioactivity of uranium and the high toxicity of uranyl ion (UO). Although uranyl-protein/DNA interactions have been known for decades, fewer advances are made in understanding their structural-functional impacts. Instead of focusing only on the structural information, this article aims to review the recent advances in understanding the binding of uranyl to proteins in either potential, native, or artificial metal-binding sites, and the structural-functional impacts of uranyl-protein interactions, such as inducing conformational changes and disrupting protein-protein/DNA/ligand interactions. Photo-induced protein/DNA cleavages, as well as other impacts, are also highlighted. These advances shed light on the structure-function relationship of proteins, especially for metalloproteins, as impacted by uranyl-protein interactions. It is desired to seek approaches for biological remediation of uranyl ions, and ultimately make a full use of the double-edged sword of uranium.
Topics: Carrier Proteins; Metalloproteins; Models, Molecular; Structure-Activity Relationship; Uranium Compounds
PubMed: 32187982
DOI: 10.3390/biom10030457 -
Redox Biology Apr 2023Reactive sulfur species (RSS) entail a diverse family of sulfur derivatives that have emerged as important effector molecules in HS-mediated biological events. RSS... (Review)
Review
Reactive sulfur species (RSS) entail a diverse family of sulfur derivatives that have emerged as important effector molecules in HS-mediated biological events. RSS (including HS) can exert their biological roles via widespread interactions with metalloproteins. Metalloproteins are essential components along the metabolic route of oxygen in the body, from the transport and storage of O, through cellular respiration, to the maintenance of redox homeostasis by elimination of reactive oxygen species (ROS). Moreover, heme peroxidases contribute to immune defense by killing pathogens using oxygen-derived HO as a precursor for stronger oxidants. Coordination and redox reactions with metal centers are primary means of RSS to alter fundamental cellular functions. In addition to RSS-mediated metalloprotein functions, the reduction of high-valent metal centers by RSS results in radical formation and opens the way for subsequent per- and polysulfide formation, which may have implications in cellular protection against oxidative stress and in redox signaling. Furthermore, recent findings pointed out the potential role of RSS as substrates for mitochondrial energy production and their cytoprotective capacity, with the involvement of metalloproteins. The current review summarizes the interactions of RSS with protein metal centers and their biological implications with special emphasis on mechanistic aspects, sulfide-mediated signaling, and pathophysiological consequences. A deeper understanding of the biological actions of reactive sulfur species on a molecular level is primordial in HS-related drug development and the advancement of redox medicine.
Topics: Hydrogen Sulfide; Metalloproteins; Hydrogen Peroxide; Reactive Oxygen Species; Oxygen; Sulfur
PubMed: 36738685
DOI: 10.1016/j.redox.2023.102617 -
Current Opinion in Chemical Biology Apr 2015Three-helix bundles and coiled-coil motifs are well-established de novo designed scaffolds that have been investigated for their metal-binding and catalytic properties.... (Review)
Review
Three-helix bundles and coiled-coil motifs are well-established de novo designed scaffolds that have been investigated for their metal-binding and catalytic properties. Satisfaction of the primary coordination sphere for a given metal is sufficient to introduce catalytic activity and a given structure may catalyze different reactions dependent on the identity of the incorporated metal. Here we describe recent contributions in the de novo design of metalloenzymes based on three-helix bundles and coiled-coil motifs, focusing on non-heme systems for hydrolytic and redox chemistry.
Topics: Copper; Drug Design; Enzymes; Metalloproteins; Protein Structure, Secondary; Zinc
PubMed: 25579452
DOI: 10.1016/j.cbpa.2014.12.034 -
Angewandte Chemie (International Ed. in... May 2020The relationship between protein structure and function is one of the greatest puzzles within biochemistry. De novo metalloprotein design is a way to wipe the board... (Review)
Review
The relationship between protein structure and function is one of the greatest puzzles within biochemistry. De novo metalloprotein design is a way to wipe the board clean and determine what is required to build in function from the ground up in an unrelated structure. This Review focuses on protein design efforts to create de novo metalloproteins within alpha-helical scaffolds. Examples of successful designs include those with carbonic anhydrase or nitrite reductase activity by incorporating a ZnHis or CuHis site, or that recapitulate the spectroscopic properties of unique electron-transfer sites in cupredoxins (CuHis Cys) or rubredoxins (FeCys ). This work showcases the versatility of alpha helices as scaffolds for metalloprotein design and the progress that is possible through careful rational design. Our studies cover the invariance of carbonic anhydrase activity with different site positions and scaffolds, refinement of our cupredoxin models, and enhancement of nitrite reductase activity up to 1000-fold.
Topics: Drug Design; Electron Transport; Metalloproteins; Protein Conformation, alpha-Helical
PubMed: 31441170
DOI: 10.1002/anie.201907502 -
International Journal of Molecular... Jul 2021Copper, manganese, and iron are vital elements required for the appropriate development and the general preservation of good health. Additionally, these essential metals... (Review)
Review
Copper, manganese, and iron are vital elements required for the appropriate development and the general preservation of good health. Additionally, these essential metals play key roles in ensuring proper brain development and function. They also play vital roles in the central nervous system as significant cofactors for several enzymes, including the antioxidant enzyme superoxide dismutase (SOD) and other enzymes that take part in the creation and breakdown of neurotransmitters in the brain. An imbalance in the levels of these metals weakens the structural, regulatory, and catalytic roles of different enzymes, proteins, receptors, and transporters and is known to provoke the development of various neurological conditions through different mechanisms, such as via induction of oxidative stress, increased α-synuclein aggregation and fibril formation, and stimulation of microglial cells, thus resulting in inflammation and reduced production of metalloproteins. In the present review, the authors focus on neurological disorders with psychiatric signs associated with copper, iron, and manganese excess and the diagnosis and potential treatment of such disorders. In our review, we described diseases related to these metals, such as aceruloplasminaemia, neuroferritinopathy, pantothenate kinase-associated neurodegeneration (PKAN) and other very rare classical NBIA forms, manganism, attention-deficit/hyperactivity disorder (ADHD), ephedrone encephalopathy, HMNDYT1-SLC30A10 deficiency (HMNDYT1), HMNDYT2-SLC39A14 deficiency, CDG2N-SLC39A8 deficiency, hepatic encephalopathy, prion disease and "prion-like disease", amyotrophic lateral sclerosis, Huntington's disease, Friedreich's ataxia, and depression.
Topics: Ceruloplasmin; Copper; Humans; Iron; Iron Metabolism Disorders; Manganese; Manganese Poisoning; Metabolic Diseases; Metalloproteins; Neuroaxonal Dystrophies; Neurodegenerative Diseases; Oxidative Stress
PubMed: 34360586
DOI: 10.3390/ijms22157820