scholarly journals Specificity of Human Sulfiredoxin for Reductant and Peroxiredoxin Oligomeric State

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 946
Author(s):  
Tom E. Forshaw ◽  
Julie A. Reisz ◽  
Kimberly J. Nelson ◽  
Rajesh Gumpena ◽  
J. Reed Lawson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Antioxidant Enzymes ◽  
Hydrogen Sulfide ◽  
Active Site ◽  
Relative Efficacy ◽  
Oligomeric Structure ◽  
Cellular Functions ◽  
Oligomeric State ◽  
Structural Requirements ◽  
First Time

Human peroxiredoxins (Prx) are a family of antioxidant enzymes involved in a myriad of cellular functions and diseases. During the reaction with peroxides (e.g., H2O2), the typical 2-Cys Prxs change oligomeric structure between higher order (do)decamers and disulfide-linked dimers, with the hyperoxidized inactive state (-SO2H) favoring the multimeric structure of the reduced enzyme. Here, we present a study on the structural requirements for the repair of hyperoxidized 2-Cys Prxs by human sulfiredoxin (Srx) and the relative efficacy of physiological reductants hydrogen sulfide (H2S) and glutathione (GSH) in this reaction. The crystal structure of the toroidal Prx1-Srx complex shows an extended active site interface. The loss of this interface within engineered Prx2 and Prx3 dimers yielded variants more resistant to hyperoxidation and repair by Srx. Finally, we reveal for the first time Prx isoform-dependent use of and potential cooperation between GSH and H2S in supporting Srx activity.

scholarly journals Structural and functional insights into the stationary-phase survival protein SurE, an important virulence factor ofBrucella abortus

2016 ◽  
Vol 72 (5) ◽  
pp. 386-396
Author(s):  
K. F. Tarique ◽  
S. A. Abdul Rehman ◽  
S. Devi ◽  
Priya Tomar ◽  
S. Gourinath
Keyword(s):  
Crystal Structure ◽  
Stationary Phase ◽  
Brucella Abortus ◽  
Active Site ◽  
Drug Target ◽  
Oligomeric State ◽  
Common Features ◽  
Terminal Domain ◽  
Important Virulence Factor ◽  
Stationary Phase Survival

The stationary-phase survival protein SurE fromBrucella abortus(BaSurE) is a metal-dependent phosphatase that is essential for the survival of this bacterium in the stationary phase of its life cycle. Here, BaSurE has been biochemically characterized and its crystal structure has been determined to a resolution of 1.9 Å. BaSurE was found to be a robust enzyme, showing activity over wide ranges of temperature and pH and with various phosphoester substrates. The active biomolecule is a tetramer and each monomer was found to consist of two domains: an N-terminal domain, which forms an approximate α + β fold, and a C-terminal domain that belongs to the α/β class. The active site lies at the junction of these two domains and was identified by the presence of conserved negatively charged residues and a bound Mg2+ion. Comparisons of BaSurE with its homologues have revealed both common features and differences in this class of enzymes. The number and arrangement of some of the equivalent secondary structures, which are seen to differ between BaSurE and its homologues, are responsible for a difference in the size of the active-site area and the overall oligomeric state of this enzyme in other organisms. As it is absent in mammals, it has the potential to be a drug target.

Influence of the presence of the heme cofactor on the JK-loop structure in indoleamine 2,3-dioxygenase 1

2020 ◽  
Vol 76 (12) ◽  
pp. 1211-1221
Author(s):  
Manon Mirgaux ◽  
Laurence Leherte ◽  
Johan Wouters
Keyword(s):  
Crystal Structure ◽  
Cancer Research ◽  
Active Site ◽  
Loop Structure ◽  
X Ray Diffraction ◽  
Dynamic Information ◽  
X Ray ◽  
Indoleamine 2,3 Dioxygenase ◽  
First Time ◽  
Heme Cofactor

Indoleamine 2,3-dioxygenase 1 has sparked interest as an immunotherapeutic target in cancer research. Its structure includes a loop, named the JK-loop, that controls the orientation of the substrate or inhibitor within the active site. However, little has been reported about the crystal structure of this loop. In the present work, the conformation of the JK-loop is determined for the first time in the presence of the heme cofactor in the active site through X-ray diffraction experiments (2.44 Å resolution). Molecular-dynamics trajectories were also obtained to provide dynamic information about the loop according to the presence of cofactor. This new structural and dynamic information highlights the importance of the JK-loop in confining the labile heme cofactor to the active site.

scholarly journals Crystal Structure of Mouse Thymidylate Synthase in Tertiary Complex with dUMP and Raltitrexed Reveals N-Terminus Architecture and Two Different Active Site Conformations

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Anna Dowierciał ◽  
Piotr Wilk ◽  
Wojciech Rypniewski ◽  
Wojciech Rode ◽  
Adam Jarmuła
Keyword(s):  
Crystal Structure ◽  
Conformational Changes ◽  
Thymidylate Synthase ◽  
Active Site ◽  
Crystal Packing ◽  
Terminal Segment ◽  
Asymmetrical Effect ◽  
Active Site Cleft ◽  
Ligand Free ◽  
First Time

The crystal structure of mouse thymidylate synthase (mTS) in complex with substrate dUMP and antifolate inhibitor Raltitrexed is reported. The structure reveals, for the first time in the group of mammalian TS structures, a well-ordered segment of 13 N-terminal amino acids, whose ordered conformation is stabilized due to specific crystal packing. The structure consists of two homodimers, differing in conformation, one being more closed (dimer AB) and thus supporting tighter binding of ligands, and the other being more open (dimer CD) and thus allowing weaker binding of ligands. This difference indicates an asymmetrical effect of the binding of Raltitrexed to two independent mTS molecules. Conformational changes leading to a ligand-induced closing of the active site cleft are observed by comparing the crystal structures of mTS in three different states along the catalytic pathway: ligand-free, dUMP-bound, and dUMP- and Raltitrexed-bound. Possible interaction routes between hydrophobic residues of the mTS protein N-terminal segment and the active site are also discussed.

scholarly journals The Crystal Structure Elucidation of a Tetrapeptide Analog of Somatostatin DOTA-Phe-D-Trp-Lys-Thr-OMe

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Sabina Diusenova ◽  
Sergey Arkhipov ◽  
Dmitry Avdeev ◽  
Pavel Dorovatovskii ◽  
Derenik Khachatryan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Active Site ◽  
Targeted Drug Delivery ◽  
Radionuclide Therapy ◽  
Structure Elucidation ◽  
Peptide Receptor Radionuclide Therapy ◽  
Peptide Receptor ◽  
Targeted Drug ◽  
First Time ◽  
Targeted Drug Delivery System

Herewith, we report for the first time the crystal structure of tetrapeptide FwKT (Phe-D-Trp-Lys-Thr), which is considered to represent an epitope for biomedically relevant hormone somatostatin. The target molecule was successfully crystalized, solved and refined as a conjugate of the tetrapeptide moiety bearing a protective group DOTA at the N-terminus and methylated at the O-terminus. The combination of a hormone active site and a powerful chelator make the substance a highly prospective targeted drug delivery system, especially for peptide receptor radionuclide therapy (PRRT) applications.

scholarly journals Crystal Structure, Exogenous Ligand Binding, and Redox Properties of an Engineered Diiron Active Site in a Bacterial Hemerythrin

2013 ◽  
Vol 52 (22) ◽  
pp. 13014-13020 ◽  
Author(s):  
Yasunori Okamoto ◽  
Akira Onoda ◽  
Hiroshi Sugimoto ◽  
Yu Takano ◽  
Shun Hirota ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ligand Binding ◽  
Active Site ◽  
Redox Properties ◽  
Exogenous Ligand

scholarly journals Investigation of Solubility Behavior of Canagliflozin Hydrate Crystals Combining Crystallographic and Hirshfeld Surface Calculations

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 298
Author(s):  
Yefen Zhu ◽  
Yanlei Kang ◽  
Ling Zhu ◽  
Kaxi Yu ◽  
Shuai Chen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Intermolecular Forces ◽  
Hirshfeld Surface ◽  
Reversible Inhibitor ◽  
Solubility Behavior ◽  
Hydrogen Bond Networks ◽  
Solvent Molecules ◽  
First Time ◽  
Better Than

Canagliflozin (CG) was a highly effective, selective and reversible inhibitor of sodium-dependent glucose co-transporter 2 developed for the treatment of type 2 diabetes mellitus. The crystal structure of CG monohydrate (CG-H2O) was reported for the first time while CG hemihydrate (CG-Hemi) had been reported in our previous research. Solubility and dissolution rate results showed that the solubility of CG-Hemi was 1.4 times higher than that of CG-H2O in water and hydrochloric acid solution, and the dissolution rates of CG-Hemi were more than 3 folds than CG-H2O in both solutions. Hirshfeld surface analysis showed that CG-H2O had stronger intermolecular forces than CG-Hemi, and water molecules in CG-H2O participated three hydrogen bonds, forming hydrogen bond networks. These crystal structure features might make it more difficult for solvent molecules to dissolve CG-H2O than CG-Hemi. All these analyses might explain why the dissolution performance of CG-Hemi was better than CG-H2O. This work provided an approach to predict the dissolution performance of the drug based on its crystal structure.

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