Elucidation of the crystal structure ofCoriolopsis caperatalaccase: restoration of the structure and activity of the native enzyme from the T2-depleted form by copper ions

2015 ◽  
Vol 71 (4) ◽  
pp. 854-861 ◽  
Author(s):  
Olga A. Glazunova ◽  
Konstantin M. Polyakov ◽  
Tatyana V. Fedorova ◽  
Pavel V. Dorovatovskii ◽  
Olga V. Koroleva
Keyword(s):  
Copper Ions ◽  
Large Family ◽  
Native Enzyme ◽  
Multicopper Oxidases ◽  
Wide Range ◽  
Inorganic Substrates ◽  
Structure And Activity ◽  
Copper Centre ◽  
High Redox Potential

Laccases are members of a large family of multicopper oxidases that catalyze the oxidation of a wide range of organic and inorganic substrates accompanied by the reduction of dioxygen to water. A new laccase was isolated from the basidiomyceteCoriolopsis caperatastrain 0677 and its amino-acid sequence was determined. According to its physicochemical properties and spectroscopic features, the laccase fromC. caperatais a high redox-potential blue laccase. Attempts to crystallize the native enzyme were unsuccessful. The copper type 2-depleted (T2D) laccase was prepared and crystallized. The structure of T2D laccase fromC. caperatawas solved at 1.6 Å resolution, and attempts to reconstruct the T2 copper centre were performed using Cu+and Cu2+ions. The structure of T2D+Cu+laccase was solved at 1.89 Å resolution. It was shown that the T2D+Cu+laccase structure contained four copper ions in the active site. Reconstruction could not be achieved when the T2D laccase crystals were treated with CuSO4.

scholarly journals Incorporation of copper ions into crystals of T2 copper-depleted laccase fromBotrytis aclada

2015 ◽  
Vol 71 (12) ◽  
pp. 1465-1469 ◽  
Author(s):  
E. M. Osipov ◽  
K. M. Polyakov ◽  
T. V. Tikhonova ◽  
R. Kittl ◽  
P.V. Dorovatovskii ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Comparative Analysis ◽  
Molecular Oxygen ◽  
Active Site ◽  
Copper Ions ◽  
Enzyme Molecule ◽  
Multicopper Oxidases ◽  
Native Form ◽  
Oxidation Of Phenols

Laccases belong to the class of multicopper oxidases catalyzing the oxidation of phenols accompanied by the reduction of molecular oxygen to water without the formation of hydrogen peroxide. The activity of laccases depends on the number of Cu atoms per enzyme molecule. The structure of type 2 copper-depleted laccase fromBotrytis acladahas been solved previously. With the aim of obtaining the structure of the native form of the enzyme, crystals of the depleted laccase were soaked in Cu+- and Cu2+-containing solutions. Copper ions were found to be incorporated into the active site only when Cu+was used. A comparative analysis of the native and depleted forms of the enzymes was performed.

Structural study of the X-ray-induced enzymatic reduction of molecular oxygen to water bySteccherinum murashkinskyilaccase: insights into the reaction mechanism

2017 ◽  
Vol 73 (5) ◽  
pp. 388-401 ◽  
Author(s):  
K. M. Polyakov ◽  
S. Gavryushov ◽  
S. Ivanova ◽  
T. V. Fedorova ◽  
O. A. Glazunova ◽  
...  
Keyword(s):  
Molecular Oxygen ◽  
Catalytic Reduction ◽  
Copper Ions ◽  
Absorbed Dose ◽  
Large Family ◽  
Data Sets ◽  
X Ray ◽  
Substrate Complex ◽  
Enzymatic Reduction ◽  
Wide Range

The laccase fromSteccherinum murashkinskyiis a member of the large family of multicopper oxidases that catalyze the oxidation of a wide range of organic and inorganic substrates, accompanied by the reduction of dioxygen to water. The reducing properties of X-ray radiation and the high quality of the laccase crystals allow the study of the catalytic reduction of dioxygen to water directly in a crystal. A series of diffraction data sets with increasing absorbed radiation dose were collected from a single crystal ofSteccherinum murashkinskyilaccase at 1.35 Å resolution. Changes in the active-site structure associated with the reduction of molecular oxygen to water on increasing the absorbed dose of ionizing radiation were detected. The structures in the series are mixtures of different states of the enzyme–substrate complex. Nevertheless, it was possible to interpret these structures as complexes of various oxygen ligands with copper ions in different oxidation states. The results allowed the mechanism of oxygen reduction catalyzed by laccases to be refined.

Biochemical properties of CumA multicopper oxidase from plant pathogen, Pseudomonas syringae

2021 ◽  
Author(s):  
Konan Ishida ◽  
Yuya Tsukamoto ◽  
Masaki Horitani ◽  
Tomohisa Ogawa ◽  
Yoshikazu Tanaka
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Cell ◽  
Plant Pathogens ◽  
Plant Cell Wall ◽  
Copper Ions ◽  
Multicopper Oxidase ◽  
Type I ◽  
Multicopper Oxidases ◽  
Oxidation Activity ◽  
Wide Range

Abstract Multicopper oxidases have a wide range of substrate specificity to be involved in various physiological reactions. Pseudomonas syringae, a plant pathogenic bacterium, has a multicopper oxidase, CumA. Multicopper oxidases have ability to degrade plant cell wall component, lignin. Once P. syringae enter apoplast and colonize, they start to disrupt plant immunity. Therefore, deeper understanding of multicopper oxidases from plant pathogens, help to invent measures to prevent invasion into plant cell, which bring agricultural benefits. Several biochemical studies have reported lower activity of CumA compared with other multicopper oxidase called CotA. However, the mechanisms underlying the difference in activity have not yet been revealed. In order to acquire insight into them, we conducted a biophysical characterization of PsCumA. Our results show that PsCumA has weak type I copper EPR signal, which is essential for oxidation activity. We propose that difference in the coordination of copper ions may decrease reaction frequency.

Structure and Activity of Pentacyclic Triterpenes Codrugs. A Review

2021 ◽  
Vol 21 ◽  
Author(s):  
Justyna Żwawiak ◽  
Anna Pawełczyk ◽  
Dorota Olender ◽  
Lucjusz Zaprutko
Keyword(s):  
Biological Activities ◽  
Anticancer Activities ◽  
Drug Molecule ◽  
Pentacyclic Triterpene ◽  
Formation Pathway ◽  
Chemical Systems ◽  
Drug Molecules ◽  
Wide Range ◽  
Anti Hiv ◽  
Structure And Activity

: Triterpenes are a wide and important group of compounds that have several promising pharmacological properties, such as hepatoprotective, anti-inflammatory, anti-HIV, antioxidant, or anticancer activities. Such potent substances can be successfully incorporated in more complex chemical systems e.g. codrugs or pro-drugs that have better pharmacological profile. The codrug is connected with a drug formation pathway to chemically cohere at least two drug molecules to improve positive therapeutic efficiency or decrease side effects. The codrug can be cleaved in the organism to generate effective compounds previously used as substrates. This article presents an overview of codrugs that consist of pentacyclic triterpene moiety that is chosen as a basic codrug moiety due to their wide range of vital activities and another drug molecule fragment. It was found that triterpenoid codrugs are characterized by a wide range of biological activities. However, most of them have anticancer potency.

scholarly journals Effect of Posttranslational Modifications on the Structure and Activity of FTO Demethylase

2021 ◽  
Vol 22 (9) ◽  
pp. 4512
Author(s):  
Michał Marcinkowski ◽  
Tomaš Pilžys ◽  
Damian Garbicz ◽  
Jan Piwowarski ◽  
Damian Mielecki ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Size Exclusion Chromatography ◽  
Posttranslational Modifications ◽  
Size Exclusion ◽  
Saxs Data ◽  
Wide Range ◽  
Exclusion Chromatography ◽  
Demethylase Activity ◽  
Structure And Activity

The FTO protein is involved in a wide range of physiological processes, including adipogenesis and osteogenesis. This two-domain protein belongs to the AlkB family of 2-oxoglutarate (2-OG)- and Fe(II)-dependent dioxygenases, displaying N6-methyladenosine (N6-meA) demethylase activity. The aim of the study was to characterize the relationships between the structure and activity of FTO. The effect of cofactors (Fe2+/Mn2+ and 2-OG), Ca2+ that do not bind at the catalytic site, and protein concentration on FTO properties expressed in either E. coli (ECFTO) or baculovirus (BESFTO) system were determined using biophysical methods (DSF, MST, SAXS) and biochemical techniques (size-exclusion chromatography, enzymatic assay). We found that BESFTO carries three phosphoserines (S184, S256, S260), while there were no such modifications in ECFTO. The S256D mutation mimicking the S256 phosphorylation moderately decreased FTO catalytic activity. In the presence of Ca2+, a slight stabilization of the FTO structure was observed, accompanied by a decrease in catalytic activity. Size exclusion chromatography and MST data confirmed the ability of FTO from both expression systems to form homodimers. The MST-determined dissociation constant of the FTO homodimer was consistent with their in vivo formation in human cells. Finally, a low-resolution structure of the FTO homodimer was built based on SAXS data.

AGN1 vs AGN2 dichotomy as seen from the point of view of ionized outflows

2019 ◽  
Vol 15 (S356) ◽  
pp. 96-96
Author(s):  
Eleonora Sani
Keyword(s):  
Accretion Rate ◽  
Point Of View ◽  
Emission Lines ◽  
Black Hole Mass ◽  
X Ray ◽  
Bolometric Luminosity ◽  
Wide Range ◽  
Strong Contrast

AbstractI present a detailed study of ionized outflows in a large sample of 650 hard X-ray detected AGN. Taking advantage of the legacy value of the BAT AGN Spectroscopic Survey (BASS, DR1), we are able to reveal the faintest wings of the [OIII] emission lines associated with outflows. The sample allows us to derive the incidence of outflows covering a wide range of AGN bolometric luminosity and test how the outflow parameters are related with various AGN power tracers, such as black hole mass, Eddington ratio, luminosity. I’ll show how ionized outflows are more frequently found in type 1.9 and type 1 AGN (50% and 40%) with respect to the low fraction in type 2 AGN (20%). Within such a framework, I’ll demonstrate how type 2 AGN outflows are almost evenly balanced between blue- and red-shifted winds. This, in strong contrast with type 1 and type 1.9 AGN outflows which are almost exclusively blue-shifted. Finally, I’ll prove how the outflow occurrence is driven by the accretion rate, whereas the dependence of outflow properties with respect to the other AGN power tracers happens to be quite mild.

scholarly journals Genome analysis of Pseudomonas sp. OF001 and Rubrivivax sp. A210 suggests multicopper oxidases catalyze manganese oxidation required for cylindrospermopsin transformation

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Erika Berenice Martínez-Ruiz ◽  
Myriel Cooper ◽  
Jimena Barrero-Canosa ◽  
Mindia A. S. Haryono ◽  
Irina Bessarab ◽  
...  
Keyword(s):  
Calvin Cycle ◽  
Multicopper Oxidase ◽  
Genomic Islands ◽  
Biotechnological Applications ◽  
High Similarity ◽  
Multicopper Oxidases ◽  
Metabolic Potential ◽  
Natural Habitats ◽  
Manganese Oxidation ◽  
Wide Range

Abstract Background Cylindrospermopsin is a highly persistent cyanobacterial secondary metabolite toxic to humans and other living organisms. Strain OF001 and A210 are manganese-oxidizing bacteria (MOB) able to transform cylindrospermopsin during the oxidation of Mn2+. So far, the enzymes involved in manganese oxidation in strain OF001 and A210 are unknown. Therefore, we analyze the genomes of two cylindrospermopsin-transforming MOB, Pseudomonas sp. OF001 and Rubrivivax sp. A210, to identify enzymes that could catalyze the oxidation of Mn2+. We also investigated specific metabolic features related to pollutant degradation and explored the metabolic potential of these two MOB with respect to the role they may play in biotechnological applications and/or in the environment. Results Strain OF001 encodes two multicopper oxidases and one haem peroxidase potentially involved in Mn2+ oxidation, with a high similarity to manganese-oxidizing enzymes described for Pseudomonas putida GB-1 (80, 83 and 42% respectively). Strain A210 encodes one multicopper oxidase potentially involved in Mn2+ oxidation, with a high similarity (59%) to the manganese-oxidizing multicopper oxidase in Leptothrix discophora SS-1. Strain OF001 and A210 have genes that might confer them the ability to remove aromatic compounds via the catechol meta- and ortho-cleavage pathway, respectively. Based on the genomic content, both strains may grow over a wide range of O2 concentrations, including microaerophilic conditions, fix nitrogen, and reduce nitrate and sulfate in an assimilatory fashion. Moreover, the strain A210 encodes genes which may convey the ability to reduce nitrate in a dissimilatory manner, and fix carbon via the Calvin cycle. Both MOB encode CRISPR-Cas systems, several predicted genomic islands, and phage proteins, which likely contribute to their genome plasticity. Conclusions The genomes of Pseudomonas sp. OF001 and Rubrivivax sp. A210 encode sequences with high similarity to already described MCOs which may catalyze manganese oxidation required for cylindrospermopsin transformation. Furthermore, the analysis of the general metabolism of two MOB strains may contribute to a better understanding of the niches of cylindrospermopsin-removing MOB in natural habitats and their implementation in biotechnological applications to treat water.

scholarly journals Chemotactic cytokines, obesity and type 2 diabetes:in vivoandin vitroevidence for a possible causal correlation?

2009 ◽  
Vol 68 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Henrike Sell ◽  
Jürgen Eckel
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Low Grade ◽  
Obese Patients ◽  
Tissue Mass ◽  
Tissue Biology ◽  
Wide Range ◽  
Adipose Tissue Mass

A strong causal link between increased adipose tissue mass and insulin resistance in tissues such as liver and skeletal muscle exists in obesity-related disorders such as type 2 diabetes. Increased adipose tissue mass in obese patients and patients with diabetes is associated with altered secretion of adipokines, which also includes chemotactic proteins. Adipose tissue releases a wide range of chemotactic proteins including many chemokines and chemerin, which are interesting targets for adipose tissue biology and for biomedical research in obesity and obesity-related diseases. This class of adipokines may be directly linked to a chronic state of low-grade inflammation and macrophage infiltration in adipose tissue, a concept intensively studied in adipose tissue biology in recent years. The inflammatory state of adipose tissue in obese patients may be the most important factor linking increased adipose tissue mass to insulin resistance. Furthermore, chemoattractant adipokines may play an important role in this situation, as many of these proteins possess biological activity beyond the recruitment of immune cells including effects on adipogenesis and glucose homeostasis in insulin-sensitive tissues. The present review provides a summary of experimental evidence of the role of adipose tissue-derived chemotactic cytokines and their function in insulin resistancein vivoandin vitro.

Chitinase 3-like-1 protects airway function despite promoting type 2 inflammation during fungal-associated allergic airway inflammation

2021 ◽  
Author(s):  
Joseph J. Mackel ◽  
Jaleesa M. Garth ◽  
MaryJane Jones ◽  
Diandra A. Ellis ◽  
Jonathan P. Blackburn ◽  
...  
Keyword(s):  
Airway Inflammation ◽  
Periodic Acid ◽  
Acute Infection ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Allergic Airway Inflammation ◽  
Lung Edema ◽  
Periodic Acid Schiff ◽  
Wide Range ◽  
Type 2 Inflammation

Exposure to fungi can result in a wide range of comorbidities depending on the immune status of the host. Chronic exposure and reactivity to fungi such as Aspergillus fumigatus can result in conditions such as severe asthma with fungal sensitization (SAFS) or allergic bronchopulmonary aspergillosis (ABPA). However, the pathophysiology of SAFS and ABPA are not well understood. Here, we report that the chitinase-like protein YKL-40 is elevated in lung lavage fluid from human asthmatics that are sensitized to fungi. Initial studies demonstrated that mice deficient in the murine ortholog of YKL-40, breast regression protein-39 (BRP-39, chitinase-3-like 1, Chi3l1), were not more susceptible to acute infection with A. fumigatus. However, in an experimental model of fungal-associated allergic airway inflammation (fungal asthma), Chi3l1-/- mice had significantly increased airway hyperresponsiveness (AHR). Surprisingly, increased AHR in Chi3l1-/- mice occurred in the presence of significantly lower type 2 responses (decreased eosinophil numbers and decreased IL-4, IL-5, IL-33, CCL17 and CCL22 levels), although type 1 and type 17 responses were not different. Increased AHR was not associated with differences in Periodic-acid-Schiff staining of lung tissue, differences in the expression of Muc5ac and Clca3, nor differences in lung edema. Bone marrow chimera studies revealed that the presence of BRP-39 in either the hematopoietic or non-hematopoietic compartment was sufficient for controlling AHR during fungal asthma. Collectively, these results indicate that BRP-39 protects against AHR during fungal asthma despite contributing to type 2 inflammation, thus highlighting an unexpected protective role for BRP-39 in allergic fungal asthma.

Model Child Care Health Policies

2013 ◽  
Author(s):  
Keyword(s):  
Child Care ◽  
Early Education ◽  
Health And Safety ◽  
Large Family ◽  
Health Policies ◽  
After School ◽  
Wide Range ◽  
Before And After ◽  
Care Health ◽  
Child Care Facilities

Significantly revised and updated, the new Model Child Care Health Policies, 5th Edition is a must-have tool to foster adoption and implemenation of best practices for health and safety in group care settings for young children. These settings include early care and education as well as before and after school child care programs. These model policies are intended to ease the burden of writing site-specific health and safety policies from scratch. They cover a wide range of aspects of operation of early education and child care programs. Child care programs of any type can use Model Child Care Health Policies by selecting relevant issues for their operation and modifying the wording to make selected policies appropriate to the specific settings. These settings include early education and child care centers, small and large family child care homes, part day-programs for ill children, facilities that serve children with special needs, school-age child care facilities, and drop-in facilities. The model policies can be adapted for public, private, Head Start, and tuition-funded facilities. All of the most commonly covered health and safety topics the National Association of Child Care Resource and Referral Agencies found in state regulations are included in this guide.

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