scholarly journals Laccase Properties, Physiological Functions, and Evolution

2020 ◽  
Vol 21 (3) ◽  
pp. 966 ◽  
Author(s):  
Grzegorz Janusz ◽  
Anna Pawlik ◽  
Urszula Świderska-Burek ◽  
Jolanta Polak ◽  
Justyna Sulej ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Catalytic Properties ◽  
Structural Characteristics ◽  
Living Systems ◽  
Biological Functions ◽  
Multicopper Oxidases ◽  
Protective Function ◽  
Physiological Functions ◽  
Substrate Specificities ◽  
Taxonomic Groups

Discovered in 1883, laccase is one of the first enzymes ever described. Now, after almost 140 years of research, it seems that this copper-containing protein with a number of unique catalytic properties is widely distributed across all kingdoms of life. Laccase belongs to the superfamily of multicopper oxidases (MCOs)—a group of enzymes comprising many proteins with different substrate specificities and diverse biological functions. The presence of cupredoxin-like domains allows all MCOs to reduce oxygen to water without producing harmful byproducts. This review describes structural characteristics and plausible evolution of laccase in different taxonomic groups. The remarkable catalytic abilities and broad substrate specificity of laccases are described in relation to other copper-containing MCOs. Through an exhaustive analysis of laccase roles in different taxa, we find that this enzyme evolved to serve an important, common, and protective function in living systems.

scholarly journals Isoelectric focusing of glutathione S-transferases from rat liver and kidney

1978 ◽  
Vol 175 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Barbara F. Hales ◽  
Valerie Jaeger ◽  
Allen H. Neims
Keyword(s):  
Substrate Specificity ◽  
Isoelectric Focusing ◽  
Transferase Activity ◽  
Sprague Dawley ◽  
Substrate Specificities ◽  
Liver Cytosol ◽  
Sprague Dawley Rats ◽  
Isoelectric Points ◽  
Liver And Kidney ◽  
Glutathione S Transferases

The glutathione S-transferases that were purified to homogeneity from liver cytosol have overlapping but distinct substrate specificities and different isoelectric points. This report explores the possibility of using preparative electrofocusing to compare the composition of the transferases in liver and kidney cytosol. Hepatic cytosol from adult male Sprague–Dawley rats was resolved by isoelectric focusing on Sephadex columns into five peaks of transferase activity, each with characteristic substrate specificity. The first four peaks of transferase activity (in order of decreasing basicity) are identified as transferases AA, B, A and C respectively, on the basis of substrate specificity, but the fifth peak (pI6.6) does not correspond to a previously described transferase. Isoelectric focusing of renal cytosol resolves only three major peaks of transferase activity, each with narrow substrate specificity. In the kidney, peak 1 (pI9.0) has most of the activity toward 1-chloro-2,4-dinitrobenzene, peak 2 (pI8.5) toward p-nitrobenzyl chloride, and peak 3 (pI7.0) toward trans-4-phenylbut-3-en-2-one. Renal transferase peak 1 (pI9.0) appears to correspond to transferase B on the basis of pI, substrate specificity and antigenicity. Kidney transferase peaks 2 (pI8.5) and 3 (pI7.0) do not correspond to previously described glutathione S-transferases, although kidney transferase peak 3 is similar to the transferase peak 5 from focused hepatic cytosol. Transferases A and C were not found in kidney cytosol, and transferase AA was detected in only one out of six replicates. Thus it is important to recognize the contribution of individual transferases to total transferase activity in that each transferase may be regulated independently.

scholarly journals Genome-Wide Identification and Expression Analyses of CONSTANS-Like Family Genes in Cucumber (Cucumis sativus L.)

2021 ◽  
Author(s):  
Zhen Tian ◽  
Xiaodong Qin ◽  
Hui Wang ◽  
Ji Li ◽  
Jinfeng Chen
Keyword(s):  
Floral Induction ◽  
Structural Characteristics ◽  
Expression Patterns ◽  
Evolutionary Relationship ◽  
Biological Functions ◽  
Promoter Regions ◽  
Cucumis Sativus L ◽  
Cis Acting ◽  
Genome Wide ◽  
Induction Process

AbstractThe CONSTANS-like (COL) gene family is one of the plant-specific transcription factor families that play important roles in plant growth and development. However, the knowledge of COLs related in cucumber is limited, and their biological functions, especially in the photoperiod-dependent flowering process, are still unclear. In this study, twelve CsaCOL genes were identified in the cucumber genome. Phylogenetic and conserved motif analyses provided insights into the evolutionary relationship between the CsaCOLs. Further, the comparative genome analysis revealed that COL genes are conserved in different plant species, especially collinearity gene pairs related to CsaCOL5. Ten kinds of cis-acting elements were vividly detected in CsaCOLs promoter regions, including five light-responsive elements, which echo the diurnal rhythm expression patterns of seven CsaCOL genes under SD and LD photoperiod regimes. Combined with the expression data of developmental stage, three CsaCOL genes are involved in the flowering network and play pivotal roles for the floral induction process. Our results provide useful information for further elucidating the structural characteristics, expression patterns, and biological functions of COL family genes in many plants

scholarly journals Escherichia coli RNase D. Catalytic properties and substrate specificity.

1981 ◽  
Vol 256 (11) ◽  
pp. 5633-5637 ◽  
Author(s):  
H. Cudny ◽  
R. Zaniewski ◽  
M.P. Deutscher
Keyword(s):  
Escherichia Coli ◽  
Substrate Specificity ◽  
Catalytic Properties

scholarly journals Transport of glutathione-conjugates in human erythrocytes.

2000 ◽  
Vol 47 (3) ◽  
pp. 751-762 ◽  
Author(s):  
R Sharma ◽  
S Awasthi ◽  
P Zimniak ◽  
Y C Awasthi
Keyword(s):  
Multidrug Resistance ◽  
Substrate Specificity ◽  
Cancer Cells ◽  
Structural Characteristics ◽  
Physiological Role ◽  
Human Erythrocytes ◽  
Environmental Toxicants ◽  
Cationic Drugs ◽  
Molecular Identity ◽  
Hydrophilic Molecule

The last step of detoxification of both endogenous and environmental toxicants is typically a conjugation that produces a bulky hydrophilic molecule. The excretion of such conjugates out of cells is of sufficient biological importance to have led to the evolution of ATP-driven export pumps for this purpose. The substrate specificity of such transporters is broad, and in some cases it has been shown to include not only anionic conjugates but also neutral or weakly cationic drugs. In the present article, we review the molecular identity, functional and structural characteristics of these pumps, mainly on the example of human erythrocytes, and discuss their physiological role in detoxification and in the multidrug resistance phenotype of cancer cells.

scholarly journals Investigation of the Structural Changes and Catalytic Properties of FeNi Nanostructures as a Result of Exposure to Gamma Radiation

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 254
Author(s):  
Daryn B. Borgekov ◽  
Maxim V. Zdorovets ◽  
Dmitriy I. Shlimas ◽  
Artem L. Kozlovskiy
Keyword(s):  
Gamma Radiation ◽  
Point Defects ◽  
Gamma Rays ◽  
Structural Changes ◽  
Catalytic Properties ◽  
Structural Characteristics ◽  
Catalytic Reactions ◽  
Radiation Doses ◽  
Crystallite Orientation ◽  
Complete Destruction

The paper presents the results of changes in the structural characteristics, and the degree of texturing of FeNi nanostructures close in composition to permalloy compounds as a result of directed modification by gamma radiation with an energy of 1.35 MeV and doses from 100 to 500 kGy. The choices of energy and radiation doses were due to the need to modify the structural properties, which consisted of annealing the point defects that occurred during the synthesis along the entire length of the nanotubes. The initial FeNi nanostructures were polycrystalline nanotubes of anisotropic crystallite orientation, obtained by electrochemical deposition. The study found that exposure to gamma rays led to fewer defects in the structure, and reorientation of crystallites, and at doses above 300 kGy, the presence of one selected texture direction (111) in the structure. During tests of the corrosion resistance of synthesized and modified nanostructures in a PBS solution at various temperatures, it was found that exposure to gamma rays led to a significant decrease in the rate of degradation of nanotubes and an increase in the potential life of up to 20 days. It was established that at the first stage of testing, the degradation of nanostructures is accompanied by the formation of oxide inclusions, which subsequently lead to the formation of pitting corrosion and subsequent partial or complete destruction of the nanostructures. It is shown that gamma radiation is promising not only for targeted modification of nanostructures and increasing resistance to degradation, but also for increasing the rate of catalytic reactions of the PNA-PPD type.

scholarly journals Novel class of glutathione transferases from cyanobacteria exhibit high catalytic activities towards naturally occurring isothiocyanates

2007 ◽  
Vol 406 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Eric Wiktelius ◽  
Gun Stenberg
Keyword(s):  
Catalytic Properties ◽  
Structural Features ◽  
Glutathione Transferases ◽  
Substrate Specificities ◽  
Catalytic Activities ◽  
Genome Databases ◽  
Naturally Occurring ◽  
Physiological Relevance ◽  
Associated Proteins

In the present paper, we report a novel class of GSTs (glutathione transferases), called the Chi class, originating from cyanobacteria and with properties not observed previously in prokaryotic enzymes. GSTs constitute a widespread multifunctional group of proteins, of which mammalian enzymes are the best characterized. Although GSTs have their origin in prokaryotes, few bacterial representatives have been characterized in detail, and the catalytic activities and substrate specificities observed have generally been very modest. The few well-studied bacterial GSTs have largely unknown physiological functions. Genome databases reveal that cyanobacteria have an extensive arsenal of glutathione-associated proteins. We have studied two cyanobacterial GSTs which are the first examples of bacterial enzymes that are as catalytically efficient as the best mammalian enzymes. GSTs from the thermophile Thermosynechococcus elongatus BP-1 and from Synechococcus elongatus PCC 6301 were found to catalyse the conjugation of naturally occurring plant-derived isothiocyanates to glutathione at high rates. The cyanobacterial GSTs studied are smaller than previously described members of this enzyme family, but display many of the typical structural features that are characteristics of GSTs. They are also active towards several classical substrates, but at the same moderate rates that have been observed for other GSTs derived from prokaryotes. The cloning, expression and characterization of two cyanobacterial GSTs are described. The possible significance of the observed catalytic properties is discussed in the context of physiological relevance and GST evolution.

scholarly journals Carbohydrate/glycan-binding specificity of legume lectins in respect to their proposed biological functions

2000 ◽  
Vol 43 (4) ◽  
pp. 349-359 ◽  
Author(s):  
Márcio Viana Ramos ◽  
Thalles Barbosa Grangeiro ◽  
Benildo Sousa Cavada ◽  
Iain Shepherd ◽  
Roberval Oliveira de Melo Lopes ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Binding Specificity ◽  
Biological Properties ◽  
The Other ◽  
Biological Functions ◽  
Main Hypothesis ◽  
Physiological Functions ◽  
Legume Plants ◽  
Legume Lectins ◽  
Structural Aspects

The lectins, proteins which specifically recognize carbohydrate moieties, have been extensively studied in many biochemical and structural aspects in order to establish the molecular basis of this non-catalytic event. On the other hand, their clinical and agricultural potentials have been growing fast. Although lectins, mainly those from legume plants, had been investigated for biological properties, studies about the physiological functions of lectins are scarce in literature. Therefore, despite the accumulated data on lectins (as proteins), the role played by these signalizing molecules is poorly discussed. In the light of our accumulated results on legume lectins, specially those obtained from plants belonging to the Diocleinae sub-tribe and available data in literature, we discuss here the main hypothesis of their functions according to their carbohydrate/glycan-binding specificity.

scholarly journals Origin and evolution of transporter substrate specificity within the NPF family

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Morten Egevang Jørgensen ◽  
Deyang Xu ◽  
Christoph Crocoll ◽  
Heidi Asschenfeldt Ernst ◽  
David Ramírez ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Biochemical Characterization ◽  
Biosynthetic Pathways ◽  
Cyanogenic Glucosides ◽  
Evolutionary Path ◽  
Substrate Specificities ◽  
Origin And Evolution ◽  
Glucosinolate Biosynthesis ◽  
Phylogenetic Lineage

Despite vast diversity in metabolites and the matching substrate specificity of their transporters, little is known about how evolution of transporter substrate specificities is linked to emergence of substrates via evolution of biosynthetic pathways. Transporter specificity towards the recently evolved glucosinolates characteristic of Brassicales is shown to evolve prior to emergence of glucosinolate biosynthesis. Furthermore, we show that glucosinolate transporters belonging to the ubiquitous NRT1/PTR FAMILY (NPF) likely evolved from transporters of the ancestral cyanogenic glucosides found across more than 2500 species outside of the Brassicales. Biochemical characterization of orthologs along the phylogenetic lineage from cassava to A. thaliana, suggests that alterations in the electrogenicity of the transporters accompanied changes in substrate specificity. Linking the evolutionary path of transporter substrate specificities to that of the biosynthetic pathways, exemplify how transporter substrate specificities originate and evolve as new biosynthesis pathways emerge.

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