scholarly journals Trypanothione-dependent glyoxalase I in Trypanosoma cruzi

2006 ◽  
Vol 400 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Neil Greig ◽  
Susan Wyllie ◽  
Tim J. Vickers ◽  
Alan H. Fairlamb
Keyword(s):  
Trypanosoma Cruzi ◽  
Leishmania Major ◽  
Subcellular Fractionation ◽  
Competitive Inhibitor ◽  
Rational Drug Design ◽  
Glyoxalase I ◽  
Glyoxalase System ◽  
Glyoxalase Ii ◽  
Rational Drug ◽  
Metal Cofactor

The glyoxalase system, comprizing glyoxalase I and glyoxalase II, is a ubiquitous pathway that detoxifies highly reactive aldehydes, such as methylglyoxal, using glutathione as a cofactor. Recent studies of Leishmania major glyoxalase I and Trypanosoma brucei glyoxalase II have revealed a unique dependence upon the trypanosomatid thiol trypanothione as a cofactor. This difference suggests that the trypanothione-dependent glyoxalase system may be an attractive target for rational drug design against the trypanosomatid parasites. Here we describe the cloning, expression and kinetic characterization of glyoxalase I from Trypanosoma cruzi. Like L. major glyoxalase I, recombinant T. cruzi glyoxalase I showed a preference for nickel as its metal cofactor. In contrast with the L. major enzyme, T. cruzi glyoxalase I was far less fast-idious in its choice of metal cofactor efficiently utilizing cobalt, manganese and zinc. T. cruzi glyoxalase I isomerized hemithio-acetal adducts of trypanothione more than 2400 times more efficiently than glutathione adducts, with the methylglyoxal adducts 2–3-fold better substrates than the equivalent phenylglyoxal adducts. However, glutathionylspermidine hemithioacetal adducts were most efficiently isomerized and the glutathionylspermidine-based inhibitor S-4-bromobenzylglutathionylspermidine was found to be a potent linear competitive inhibitor of the T. cruzi enzyme with a Ki of 5.4±0.6 μM. Prediction algorithms, combined with subcellular fractionation, suggest that T. cruzi glyoxalase I localizes not only to the cytosol but also the mitochondria of T. cruzi epimastigotes. The contrasting substrate specificities of human and trypanosomatid glyoxalase enzymes, confirmed in the present study, suggest that the glyoxalase system may be an attractive target for anti-trypanosomal chemotherapy.

scholarly journals Preliminary Characterization of a Ni2+-Activated and Mycothiol-Dependent Glyoxalase I Enzyme from Streptomyces coelicolor

Inorganics ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 99 ◽  
Author(s):  
Uthaiwan Suttisansanee ◽  
John F. Honek
Keyword(s):  
Leishmania Major ◽  
Homo Sapiens ◽  
Streptomyces Coelicolor ◽  
Glyoxalase I ◽  
Glyoxalase System ◽  
Genetic Studies ◽  
Preliminary Characterization ◽  
Glyoxalase Ii ◽  
Activation Profile

The glyoxalase system consists of two enzymes, glyoxalase I (Glo1) and glyoxalase II (Glo2), and converts a hemithioacetal substrate formed between a cytotoxic alpha-ketoaldehyde, such as methylglyoxal (MG), and an intracellular thiol, such as glutathione, to a non-toxic alpha-hydroxy acid, such as d-lactate, and the regenerated thiol. Two classes of Glo1 have been identified. The first is a Zn2+-activated class and is exemplified by the Homo sapiens Glo1. The second class is a Ni2+-activated enzyme and is exemplified by the Escherichia coli Glo1. Glutathione is the intracellular thiol employed by Glo1 from both these sources. However, many organisms employ other intracellular thiols. These include trypanothione, bacillithiol, and mycothiol. The trypanothione-dependent Glo1 from Leishmania major has been shown to be Ni2+-activated. Genetic studies on Bacillus subtilis and Corynebacterium glutamicum focused on MG resistance have indicated the likely existence of Glo1 enzymes employing bacillithiol or mycothiol respectively, although no protein characterizations have been reported. The current investigation provides a preliminary characterization of an isolated mycothiol-dependent Glo1 from Streptomyces coelicolor. The enzyme has been determined to display a Ni2+-activation profile and indicates that Ni2+-activated Glo1 are indeed widespread in nature regardless of the intracellular thiol employed by an organism.

scholarly journals Inhibition mechanism of human sterol O-acyltransferase 1 by competitive inhibitor

2020 ◽  
Author(s):  
Chengcheng Guan ◽  
Yange Niu ◽  
Si-Cong Chen ◽  
Yunlu Kang ◽  
Jing-Xiang Wu ◽  
...  
Keyword(s):  
Competitive Inhibitor ◽  
Rational Drug Design ◽  
Mechanistic Study ◽  
Inhibition Mechanism ◽  
Cholesteryl Esters ◽  
Active Site Residues ◽  
Molecule Inhibitor ◽  
Rational Drug ◽  
Membrane Bound ◽  
Cholesterol Storage

AbstractSterol O-acyltransferase 1 (SOAT1) is an endoplasmic reticulum (ER) resident, multi-transmembrane enzyme that belongs to the membrane-bound O-acyltransferase (MBOAT) family 1. It catalyzes the esterification of cholesterol to generate cholesteryl esters for cholesterol storage 2. SOAT1 is a target to treat several human diseases 3. However, its structure and mechanism remain elusive since its discovery. Here, we report the structure of human SOAT1 (hSOAT1) determined by cryo-EM. hSOAT1 is a tetramer consisted of a dimer of dimer. The structure of hSOAT1 dimer at 3.5 Å resolution reveals that the small molecule inhibitor CI-976 binds inside the catalytic chamber and blocks the accessibility of the active site residues H460, N421 and W420. Our results pave the way for future mechanistic study and rational drug design of SOAT1 and other mammalian MBOAT family members.

scholarly journals A Key Role for Old Yellow Enzyme in the Metabolism of Drugs by Trypanosoma cruzi

2002 ◽  
Vol 196 (9) ◽  
pp. 1241-1252 ◽  
Author(s):  
Bruno Kilunga Kubata ◽  
Zakayi Kabututu ◽  
Tomoyoshi Nozaki ◽  
Craig J. Munday ◽  
Shunichi Fukuzumi ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Rational Drug Design ◽  
Old Yellow Enzyme ◽  
Isolation And Characterization ◽  
Drug Metabolizing Enzyme ◽  
Rational Drug ◽  
First Choice ◽  
Spin Resonance ◽  
Electron Reduction ◽  
Metabolizing Enzyme

Trypanosoma cruzi is the etiological agent of Chagas' disease. So far, first choice anti-chagasic drugs in use have been shown to have undesirable side effects in addition to the emergence of parasite resistance and the lack of prospect for vaccine against T. cruzi infection. Thus, the isolation and characterization of molecules essential in parasite metabolism of the anti-chagasic drugs are fundamental for the development of new strategies for rational drug design and/or the improvement of the current chemotherapy. While searching for a prostaglandin (PG) F2α synthase homologue, we have identified a novel “old yellow enzyme” from T. cruzi (TcOYE), cloned its cDNA, and overexpressed the recombinant enzyme. Here, we show that TcOYE reduced 9,11-endoperoxide PGH2 to PGF2α as well as a variety of trypanocidal drugs. By electron spin resonance experiments, we found that TcOYE specifically catalyzed one-electron reduction of menadione and β-lapachone to semiquinone-free radicals with concomitant generation of superoxide radical anions, while catalyzing solely the two-electron reduction of nifurtimox and 4-nitroquinoline-N-oxide drugs without free radical production. Interestingly, immunoprecipitation experiments revealed that anti-TcOYE polyclonal antibody abolished major reductase activities of the lysates toward these drugs, identifying TcOYE as a key drug-metabolizing enzyme by which quinone drugs have their mechanism of action.

Glyoxalase Centennial conference: introduction, history of research on the glyoxalase system and future prospects

2014 ◽  
Vol 42 (2) ◽  
pp. 413-418 ◽  
Author(s):  
Naila Rabbani ◽  
Paul J. Thornalley
Keyword(s):  
Physiological Function ◽  
Physiological Stress ◽  
Glyoxalase I ◽  
Future Prospects ◽  
Glyoxalase System ◽  
Introduction History ◽  
Glyoxalase Ii ◽  
History Of Research ◽  
History Of ◽  
The University

On 27–29 November 2013, researchers gathered at the University of Warwick, Coventry, U.K., to celebrate the centennial of the discovery of the glyoxalase pathway. The glyoxalase system was discovered and reported in papers by Carl Neuberg and by Henry Drysdale Dakin and Harold Ward Dudley in 1913. All three were leading extraordinary investigators in the pioneering years of biochemistry. Neuberg proposed glyoxalase as the pathway of mainstream glycolysis and Gustav Embden correctly discounted this, later confirmed by Otto Meyerhof. Albert Szent-Györgyi proposed glyoxalase I as the regulator of cell growth and others discounted this. In the meantime, molecular, structural and mechanistic properties of the enzymatic components of the system, glyoxalase I and glyoxalase II, have been characterized. The physiological function of the glyoxalase pathway of enzymatic defence against dicarbonyl glycation, particularly by endogenous methylglyoxal, now seems secure. We are now in an era of investigation of the regulation of the glyoxalase system where a role in aging and disease, physiological stress and drug resistance and development of healthier foods and new pharmaceuticals is emerging. The history of glyoxalase research illustrates the scientific process of hypothesis proposal, testing and rejection or acceptance with further investigation, standing testament to the need for intuition guided by experience and expertise, as well as indefatigable experimentation.

scholarly journals γδ-Dioxovalerate as a substrate for the glyoxalase enzyme system

1973 ◽  
Vol 135 (4) ◽  
pp. 713-719 ◽  
Author(s):  
Tadeusz Jerzykowski ◽  
Romana Winter ◽  
Wojciech Matuszewski
Keyword(s):  
Enzyme System ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Glyoxalase I ◽  
Glyoxalase System ◽  
Thiol Ester ◽  
Glyoxalase Ii ◽  
Metabolic Functions ◽  
Metabolic Role

1. Crude γδ-dioxovalerate was synthesized from laevulinate by two different methods and was purified by Sephadex chromatography. Some analytical reactions of the compound are described. 2. γδ-Dioxovalerate is a substrate for glyoxalase I and the GSH derivative formed by this enzyme is hydrolysed by glyoxalase II to form d-α-hydroxyglutarate. The Km of glyoxalase I for γδ-dioxovalerate is 1.0×10−3m at pH5.8.3. The u.v.-absorption spectrum of thiol ester, synthesized enzymically from γδ-dioxovalerate and GSH by glyoxalase I, is almost identical with that for S-lactoylglutathione. Some optical properties of this thiol ester were measured. 4. Attempts to show reversibility of the glyoxalase system reactions with d-α-hydroxyglutarate as substrate were unsuccessful. 5. The possible metabolic role of the γδ-dioxovalerate reaction is discussed. It is suggested that one of the metabolic functions of the glyoxalase system may be to provide a mechanism for the entry of this compound into the tricarboxylic acid cycle.

scholarly journals Molecular Characterization of Tc964, A Novel Antigenic Protein from Trypanosoma cruzi

2020 ◽  
Vol 21 (7) ◽  
pp. 2432
Author(s):  
Elizabeth Ruiz-Márvez ◽  
César Augusto Ramírez ◽  
Eliana Rocío Rodríguez ◽  
Magda Mellisa Flórez ◽  
Gabriela Delgado ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Trypanosoma Cruzi ◽  
Molecular Characterization ◽  
Leishmania Major ◽  
Hypothetical Protein ◽  
Subcellular Fractionation ◽  
Cross Reactivity ◽  
Preliminary Evaluation ◽  
Fractionation Analysis

The Tc964 protein was initially identified by its presence in the interactome associated with the LYT1 mRNAs, which code for a virulence factor of Trypanosoma cruzi. Tc964 is annotated in the T. cruzi genome as a hypothetical protein. According to phylogenetic analysis, the protein is conserved in the different genera of the Trypanosomatidae family; however, recognizable orthologues were not identified in other groups of organisms. Therefore, as a first step, an in-depth molecular characterization of the Tc946 protein was carried out. Based on structural predictions and molecular dynamics studies, the Tc964 protein would belong to a particular class of GTPases. Subcellular fractionation analysis indicated that Tc964 is a nucleocytoplasmic protein. Additionally, the protein was expressed as a recombinant protein in order to analyze its antigenicity with sera from Chagas disease (CD) patients. Tc964 was found to be antigenic, and B-cell epitopes were mapped by the use of synthetic peptides. In parallel, the Leishmania major homologue (Lm964) was also expressed as recombinant protein and used for a preliminary evaluation of antigen cross-reactivity in CD patients. Interestingly, Tc964 was recognized by sera from Chronic CD (CCD) patients at different stages of disease severity, but no reactivity against this protein was observed when sera from Colombian patients with cutaneous leishmaniasis were analyzed. Therefore, Tc964 would be adequate for CD diagnosis in areas where both infections (CD and leishmaniasis) coexist, even though additional assays using larger collections of sera are needed in order to confirm its usefulness for differential serodiagnosis.

Improving the Accuracy of Protein-Ligand Binding Affinity Prediction by Deep Learning Models: Benchmark and Model

2019 ◽  
Author(s):  
Mohammad Rezaei ◽  
Yanjun Li ◽  
Xiaolin Li ◽  
Chenglong Li
Keyword(s):  
Deep Learning ◽  
Drug Design ◽  
Binding Affinity ◽  
Benchmark Dataset ◽  
Rational Drug Design ◽  
Learning Models ◽  
Structure Based Drug Design ◽  
Binding Affinity Prediction ◽  
Affinity Prediction ◽  
Rational Drug

<b>Introduction:</b> The ability to discriminate among ligands binding to the same protein target in terms of their relative binding affinity lies at the heart of structure-based drug design. Any improvement in the accuracy and reliability of binding affinity prediction methods decreases the discrepancy between experimental and computational results.<br><b>Objectives:</b> The primary objectives were to find the most relevant features affecting binding affinity prediction, least use of manual feature engineering, and improving the reliability of binding affinity prediction using efficient deep learning models by tuning the model hyperparameters.<br><b>Methods:</b> The binding site of target proteins was represented as a grid box around their bound ligand. Both binary and distance-dependent occupancies were examined for how an atom affects its neighbor voxels in this grid. A combination of different features including ANOLEA, ligand elements, and Arpeggio atom types were used to represent the input. An efficient convolutional neural network (CNN) architecture, DeepAtom, was developed, trained and tested on the PDBbind v2016 dataset. Additionally an extended benchmark dataset was compiled to train and evaluate the models.<br><b>Results: </b>The best DeepAtom model showed an improved accuracy in the binding affinity prediction on PDBbind core subset (Pearson’s R=0.83) and is better than the recent state-of-the-art models in this field. In addition when the DeepAtom model was trained on our proposed benchmark dataset, it yields higher correlation compared to the baseline which confirms the value of our model.<br><b>Conclusions:</b> The promising results for the predicted binding affinities is expected to pave the way for embedding deep learning models in virtual screening and rational drug design fields.

Rational Drug Design Approach of Receptor Tyrosine Kinase Type III Inhibitors

2020 ◽  
Vol 26 (42) ◽  
pp. 7623-7640 ◽  
Author(s):  
Cheolhee Kim ◽  
Eunae Kim
Keyword(s):  
Drug Design ◽  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Synergistic Effects ◽  
Rational Drug Design ◽  
Computational Techniques ◽  
Biological Targets ◽  
Type Iii ◽  
Theoretical Approaches ◽  
Rational Drug

: Rational drug design is accomplished through the complementary use of structural biology and computational biology of biological macromolecules involved in disease pathology. Most of the known theoretical approaches for drug design are based on knowledge of the biological targets to which the drug binds. This approach can be used to design drug molecules that restore the balance of the signaling pathway by inhibiting or stimulating biological targets by molecular modeling procedures as well as by molecular dynamics simulations. Type III receptor tyrosine kinase affects most of the fundamental cellular processes including cell cycle, cell migration, cell metabolism, and survival, as well as cell proliferation and differentiation. Many inhibitors of successful rational drug design show that some computational techniques can be combined to achieve synergistic effects.

Recent Advances in the Rational Drug Design Based on Multi-target Ligands

2020 ◽  
Vol 27 (28) ◽  
pp. 4720-4740 ◽  
Author(s):  
Ting Yang ◽  
Xin Sui ◽  
Bing Yu ◽  
Youqing Shen ◽  
Hailin Cong
Keyword(s):  
Drug Resistance ◽  
Clinical Practice ◽  
Side Effects ◽  
Drug Design ◽  
Rational Drug Design ◽  
Health Conditions ◽  
Pharmacokinetic Parameters ◽  
Single Target ◽  
Rational Drug ◽  
Huge Challenge

Multi-target drugs have gained considerable attention in the last decade owing to their advantages in the treatment of complex diseases and health conditions linked to drug resistance. Single-target drugs, although highly selective, may not necessarily have better efficacy or fewer side effects. Therefore, more attention is being paid to developing drugs that work on multiple targets at the same time, but developing such drugs is a huge challenge for medicinal chemists. Each target must have sufficient activity and have sufficiently characterized pharmacokinetic parameters. Multi-target drugs, which have long been known and effectively used in clinical practice, are briefly discussed in the present article. In addition, in this review, we will discuss the possible applications of multi-target ligands to guide the repositioning of prospective drugs.

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