scholarly journals Structure of the novel monomeric glyoxalase I fromZea mays

2015 ◽  
Vol 71 (10) ◽  
pp. 2009-2020 ◽  
Author(s):  
Gino L. Turra ◽  
Romina B. Agostini ◽  
Carolina M. Fauguel ◽  
Daniel A. Presello ◽  
Carlos S. Andreo ◽  
...  
Keyword(s):  
Active Site ◽  
Higher Plants ◽  
Metabolic Stress ◽  
Glyoxalase I ◽  
The Novel ◽  
Pathogenic Microorganisms ◽  
Glyoxalase System ◽  
Single Polypeptide ◽  
Metabolic Stresses ◽  
Metabolic Byproduct

The glyoxalase system is ubiquitous among all forms of life owing to its central role in relieving the cell from the accumulation of methylglyoxal, a toxic metabolic byproduct. In higher plants, this system is upregulated under diverse metabolic stress conditions, such as in the defence response to infection by pathogenic microorganisms. Despite their proven fundamental role in metabolic stresses, plant glyoxalases have been poorly studied. In this work, glyoxalase I fromZea mayshas been characterized both biochemically and structurally, thus reporting the first atomic model of a glyoxalase I available from plants. The results indicate that this enzyme comprises a single polypeptide with two structurally similar domains, giving rise to two lateral concavities, one of which harbours a functional nickel(II)-binding active site. The putative function of the remaining cryptic active site remains to be determined.

scholarly journals A unique Ni2+ -dependent and methylglyoxal-inducible rice glyoxalase I possesses a single active site and functions in abiotic stress response

2014 ◽  
Vol 78 (6) ◽  
pp. 951-963 ◽  
Author(s):  
Ananda Mustafiz ◽  
Ajit Ghosh ◽  
Amit K. Tripathi ◽  
Charanpreet Kaur ◽  
Akshay K. Ganguly ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Response ◽  
Active Site ◽  
Glyoxalase I ◽  
Abiotic Stress Response

scholarly journals Halogen Bond Interactions of Novel HIV-1 Protease Inhibitors (PI) (GRL-001-15 and GRL-003-15) with the Flap of Protease Are Critical for Their Potent Activity against Wild-Type HIV-1 and Multi-PI-Resistant Variants

2019 ◽  
Vol 63 (6) ◽  
Author(s):  
Shin-ichiro Hattori ◽  
Hironori Hayashi ◽  
Haydar Bulut ◽  
Kalapala Venkateswara Rao ◽  
Prasanth R. Nyalapatla ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Protease Inhibitors ◽  
Active Site ◽  
Fluorine Atom ◽  
Halogen Bond ◽  
The Novel ◽  
Wild Type ◽  
Flap Region ◽  
Hiv 1

ABSTRACTWe generated two novel nonpeptidic HIV-1 protease inhibitors (PIs), GRL-001-15 and GRL-003-15, which contain unique crown-like tetrahydropyranofuran (Crn-THF) and P2′-cyclopropyl-aminobenzothiazole (Cp-Abt) moieties as P2 and P2′ ligands, respectively. GRL-001-15 and GRL-003-15 havemeta-monofluorophenyl andpara-monofluorophenyl at the P1 site, respectively, exert highly potent activity against wild-type HIV-1 with 50% effective concentrations (EC50s) of 57 and 50 pM, respectively, and have favorable cytotoxicity profiles with 50% cytotoxic concentrations (CC50s) of 38 and 11 μM, respectively. The activity of GRL-001-15 against multi-PI-resistant HIV-1 variants was generally greater than that of GRL-003-15. The EC50of GRL-001-15 against an HIV-1 variant that was highly resistant to multiple PIs, including darunavir (DRV) (HIV-1DRVRP30), was 0.17 nM, and that of GRL-003-15 was 3.3 nM, while DRV was much less active, with an EC50of 216 nM. The emergence of HIV-1 variants resistant to GRL-001-15 and GRL-003-15 was significantly delayed compared to that of variants resistant to selected PIs, including DRV. Structural analyses of wild-type protease (PRWT) complexed with the novel PIs revealed that GRL-001-15’smeta-fluorine atom forms halogen bond interactions (2.9 and 3.0 Å) with Gly49 and Ile50, respectively, of the protease flap region and with Pro81′ (2.7 and 3.2 Å), which is located close to the protease active site, and that two fluorine atoms of GRL-142-13 form multiple halogen bond interactions with Gly49, Ile50, Pro81′, Ile82′, and Arg8′. In contrast, GRL-003-15 forms halogen bond interactions with Pro81′ alone, suggesting that the reduced antiviral activity of GRL-003-15 is due to the loss of the interactions with the flap region.

scholarly journals Induced cardiac pacemaker cells survive metabolic stress owing to their low metabolic demand

2019 ◽  
Vol 51 (9) ◽  
pp. 1-12 ◽  
Author(s):  
Jin-mo Gu ◽  
Sandra I. Grijalva ◽  
Natasha Fernandez ◽  
Elizabeth Kim ◽  
D. Brian Foster ◽  
...  
Keyword(s):  
Ventricular Myocytes ◽  
Cardiac Pacemaker ◽  
Metabolic Stress ◽  
Mitochondrial Morphology ◽  
Electrical Excitation ◽  
Metabolic Demand ◽  
Pacemaker Cells ◽  
Membrane Fusion Protein ◽  
Mitochondrial Inner Membrane ◽  
Metabolic Stresses

Abstract Cardiac pacemaker cells of the sinoatrial node initiate each and every heartbeat. Compared with our understanding of the constituents of their electrical excitation, little is known about the metabolic underpinnings that drive the automaticity of pacemaker myocytes. This lack is largely owing to the scarcity of native cardiac pacemaker myocytes. Here, we take advantage of induced pacemaker myocytes generated by TBX18-mediated reprogramming (TBX18-iPMs) to investigate comparative differences in the metabolic program between pacemaker myocytes and working cardiomyocytes. TBX18-iPMs were more resistant to metabolic stresses, exhibiting higher cell viability upon oxidative stress. TBX18-induced pacemaker myocytes (iPMs) expensed a lower degree of oxidative phosphorylation and displayed a smaller capacity for glycolysis compared with control ventricular myocytes. Furthermore, the mitochondria were smaller in TBX18-iPMs than in the control. We reasoned that a shift in the balance between mitochondrial fusion and fission was responsible for the smaller mitochondria observed in TBX18-iPMs. We identified a mitochondrial inner membrane fusion protein, Opa1, as one of the key mediators of this process and demonstrated that the suppression of Opa1 expression increases the rate of synchronous automaticity in TBX18-iPMs. Taken together, our data demonstrate that TBX18-iPMs exhibit a low metabolic demand that matches their mitochondrial morphology and ability to withstand metabolic insult.

scholarly journals Identification of Potent VHZ Phosphatase Inhibitors with Structure-Based Virtual Screening

2012 ◽  
Vol 18 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Hwangseo Park ◽  
So Ya Park ◽  
Jung Jin Oh ◽  
Seong Eon Ryu
Keyword(s):  
Virtual Screening ◽  
Active Site ◽  
Structural Features ◽  
Drug Candidate ◽  
The Novel ◽  
Anticancer Activities ◽  
Phosphatase Inhibitors ◽  
Structure Activity ◽  
Promising Target ◽  
Further Development

VH1-like phosphatase Z (VHZ) has proved to be a promising target for the development of therapeutics for the treatment of human cancers. Here, we report the first example for a successful application of structure-based virtual screening to identify the novel small-molecule inhibitors of VHZ. These inhibitors revealed high potencies with the associated IC50 values ranging from 3 to 20 µM and were also screened for having desirable physicochemical properties as a drug candidate. Therefore, they deserve consideration for further development by structure-activity relationship studies to optimize inhibitory and anticancer activities. Structural features relevant to the stabilization of the newly identified inhibitors in the active site of VHZ are discussed in detail.

scholarly journals Novel Group of AChE Reactivators—Synthesis, In Vitro Reactivation and Molecular Docking Study

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2291 ◽  
Author(s):  
David Malinak ◽  
Eugenie Nepovimova ◽  
Daniel Jun ◽  
Kamil Musilek ◽  
Kamil Kuca
Keyword(s):  
Molecular Docking ◽  
Molecular Modelling ◽  
Active Site ◽  
Molecular Design ◽  
Docking Study ◽  
The Novel ◽  
Molecular Docking Study ◽  
Causal Treatment ◽  
Modelling Study

The acetylcholinesterase (AChE) reactivators (e.g., obidoxime, asoxime) became an essential part of organophosphorus (OP) poisoning treatment, together with atropine and diazepam. They are referred to as a causal treatment of OP poisoning, because they are able to split the OP moiety from AChE active site and thus renew its function. In this approach, fifteen novel AChE reactivators were determined. Their molecular design originated from former K-oxime compounds K048 and K074 with remaining oxime part of the molecule and modified part with heteroarenium moiety. The novel compounds were prepared, evaluated in vitro on human AChE (HssAChE) inhibited by tabun, paraoxon, methylparaoxon or DFP and compared to commercial HssAChE reactivators (pralidoxime, methoxime, trimedoxime, obidoxime, asoxime) or previously prepared compounds (K048, K074, K075, K203). Some of presented oxime reactivators showed promising ability to reactivate HssAChE comparable or higher than the used standards. The molecular modelling study was performed with one compound that presented the ability to reactivate GA-inhibited HssAChE. The SAR features concerning the heteroarenium part of the reactivator’s molecule are described.

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.

Synthesis, characterization, and some properties of two types of new [Fe]-H2ase models containing a 4-phosphatopyridine or a 4-phosphatoguanosinepyridine moiety

2020 ◽  
Vol 44 (42) ◽  
pp. 18496-18507
Author(s):  
Li-Cheng Song ◽  
Wei Chen ◽  
Liang Zhu ◽  
Fu-Qiang Hu ◽  
Kai-Yu Jiang
Keyword(s):  
Active Site ◽  
The Novel

The novel [Fe]-H2ase active site framework-containing model 6 was first prepared and structurally characterized.

Glyoxalase I – structure, function and a critical role in the enzymatic defence against glycation

2003 ◽  
Vol 31 (6) ◽  
pp. 1343-1348 ◽  
Author(s):  
P.J. Thornalley
Keyword(s):  
Metal Ion ◽  
Catalytic Mechanism ◽  
Critical Role ◽  
Glyoxalase I ◽  
Water Molecules ◽  
Glyoxalase System ◽  
E Coli ◽  
Antimalarial Agents

Glyoxalase I is part of the glyoxalase system present in the cytosol of cells. The glyoxalase system catalyses the conversion of reactive, acyclic α-oxoaldehydes into the corresponding α-hydroxyacids. Glyoxalase I catalyses the isomerization of the hemithioacetal, formed spontaneously from α-oxoaldehyde and GSH, to S-2-hydroxyacylglutathione derivatives [RCOCH(OH)-SG→RCH(OH)CO-SG], and in so doing decreases the steady-state concentrations of physiological α-oxoaldehydes and associated glycation reactions. Physiological substrates of glyoxalase I are methylglyoxal, glyoxal and other acyclic α-oxoaldehydes. Human glyoxalase I is a dimeric Zn2+ metalloenzyme of molecular mass 42 kDa. Glyoxalase I from Escherichia coli is a Ni2+ metalloenzyme. The crystal structures of human and E. coli glyoxalase I have been determined to 1.7 and 1.5 Å resolution. The Zn2+ site comprises two structurally equivalent residues from each domain – Gln-33A, Glu-99A, His-126B, Glu-172B and two water molecules. The Ni2+ binding site comprises His-5A, Glu-56A, His-74B, Glu-122B and two water molecules. The catalytic reaction involves base-catalysed shielded-proton transfer from C-1 to C-2 of the hemithioacetal to form an ene-diol intermediate and rapid ketonization to the thioester product. R- and S-enantiomers of the hemithioacetal are bound in the active site, displacing the water molecules in the metal ion primary co-ordination shell. It has been proposed that Glu-172 is the catalytic base for the S-substrate enantiomer and Glu-99 the catalytic base for the R-substrate enantiomer; Glu-172 then reprotonates the ene-diol stereospecifically to form the R-2-hydroxyacylglutathione product. By analogy with the human enzyme, Glu-56 and Glu-122 may be the bases involved in the catalytic mechanism of E. coli glyoxalase I. The suppression of α-oxoaldehyde-mediated glycation by glyoxalase I is particularly important in diabetes and uraemia, where α-oxoaldehyde concentrations are increased. Decreased glyoxalase I activity in situ due to the aging process and oxidative stress results in increased glycation and tissue damage. Inhibition of glyoxalase I pharmacologically with specific inhibitors leads to the accumulation of α-oxoaldehydes to cytotoxic levels; cell-permeable glyoxalase I inhibitors are antitumour and antimalarial agents. Glyoxalase I has a critical role in the prevention of glycation reactions mediated by methylglyoxal, glyoxal and other α-oxoaldehydes in vivo.

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