Crystal structure of Plasmodium falciparum adenosine deaminase reveals a novel binding pocket for inosine

2019 ◽  
Vol 667 ◽  
pp. 6-13
Author(s):  
Aritsara Jaruwat ◽  
Pinpunya Riangrungroj ◽  
Sakunrat Ubonprasert ◽  
Udom Sae-ueng ◽  
Buabarn Kuaprasert ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yufei Han ◽  
Qian Zhuang ◽  
Bo Sun ◽  
Wenping Lv ◽  
Sheng Wang ◽  
...  

AbstractSteroid hormones are essential in stress response, immune system regulation, and reproduction in mammals. Steroids with 3-oxo-Δ4 structure, such as testosterone or progesterone, are catalyzed by steroid 5α-reductases (SRD5As) to generate their corresponding 3-oxo-5α steroids, which are essential for multiple physiological and pathological processes. SRD5A2 is already a target of clinically relevant drugs. However, the detailed mechanism of SRD5A-mediated reduction remains elusive. Here we report the crystal structure of PbSRD5A from Proteobacteria bacterium, a homolog of both SRD5A1 and SRD5A2, in complex with the cofactor NADPH at 2.0 Å resolution. PbSRD5A exists as a monomer comprised of seven transmembrane segments (TMs). The TM1-4 enclose a hydrophobic substrate binding cavity, whereas TM5-7 coordinate cofactor NADPH through extensive hydrogen bonds network. Homology-based structural models of HsSRD5A1 and -2, together with biochemical characterization, define the substrate binding pocket of SRD5As, explain the properties of disease-related mutants and provide an important framework for further understanding of the mechanism of NADPH mediated steroids 3-oxo-Δ4 reduction. Based on these analyses, the design of therapeutic molecules targeting SRD5As with improved specificity and therapeutic efficacy would be possible.


2008 ◽  
Vol 73 (4) ◽  
pp. 1010-1020 ◽  
Author(s):  
P. Gayathri ◽  
I. N. Sujay Subbayya ◽  
Chethan S. Ashok ◽  
T. Senthamizh Selvi ◽  
Hemalatha Balaram ◽  
...  

2005 ◽  
Vol 187 (7) ◽  
pp. 2386-2394 ◽  
Author(s):  
Cheryl Ingram-Smith ◽  
Andrea Gorrell ◽  
Sarah H. Lawrence ◽  
Prabha Iyer ◽  
Kerry Smith ◽  
...  

ABSTRACT Acetate kinase catalyzes the reversible magnesium-dependent synthesis of acetyl phosphate by transfer of the ATP γ-phosphoryl group to acetate. Inspection of the crystal structure of the Methanosarcina thermophila enzyme containing only ADP revealed a solvent-accessible hydrophobic pocket formed by residues Val93, Leu122, Phe179, and Pro232 in the active site cleft, which identified a potential acetate binding site. The hypothesis that this was a binding site was further supported by alignment of all acetate kinase sequences available from databases, which showed strict conservation of all four residues, and the recent crystal structure of the M. thermophila enzyme with acetate bound in this pocket. Replacement of each residue in the pocket produced variants with Km values for acetate that were 7- to 26-fold greater than that of the wild type, and perturbations of this binding pocket also altered the specificity for longer-chain carboxylic acids and acetyl phosphate. The kinetic analyses of variants combined with structural modeling indicated that the pocket has roles in binding the methyl group of acetate, influencing substrate specificity, and orienting the carboxyl group. The kinetic analyses also indicated that binding of acetyl phosphate is more dependent on interactions of the phosphate group with an unidentified residue than on interactions between the methyl group and the hydrophobic pocket. The analyses also indicated that Phe179 is essential for catalysis, possibly for domain closure. Alignments of acetate kinase, propionate kinase, and butyrate kinase sequences obtained from databases suggested that these enzymes have similar catalytic mechanisms and carboxylic acid substrate binding sites.


2004 ◽  
Vol 335 (5) ◽  
pp. 1251-1264 ◽  
Author(s):  
K. Eaazhisai ◽  
R. Jayalakshmi ◽  
P. Gayathri ◽  
R.P. Anand ◽  
K. Sumathy ◽  
...  

2015 ◽  
Vol 10 (4) ◽  
pp. 917 ◽  
Author(s):  
Mukesh Kumar Kumawat ◽  
Dipak Chetia

<p class="Abstract">Seven novel dispiro-1,2,4,5-tetraoxane derivatives were synthesized and characterized by a number of analytical and spectroscopic techniques. The molecules were subsequently screened for in vitro antimalarial activity against chloroquine resistant strain of <em>Plasmodium falciparum</em> (RKL-9). At antimalarial activity screening, two compounds, namely 5d (MIC = 15.6 µg/mL or 64.5 µM) and 5f (MIC = 15.6 µg/mL or 54.6 µM) were found to be about 1.5 times more potent against chloroquine resistant strain-RKL-9 compared to chloroquine (MIC = 25.0 µg/mL or 78.3 µM). Molecular docking studies of potent ligands were also performed in cysteine protease binding pocket residues of falcipain-2 as a target protein.</p><p> </p>


2010 ◽  
Vol 9 (3) ◽  
pp. 479-486
Author(s):  
Rizna Triana Dewi ◽  
Yulia Anita ◽  
Enade Perdana Istyastono ◽  
Akhmad Darmawan ◽  
Muhamad Hanafi

Interaction of sulochrin to active site of glucosidase enzyme of Termotoga maritime has been studied by employing docking method using Molecular Operating Environment (MOE), in comparison with those are reports of established inhibitor α-glucosidase such as acarbose, miglitol and voglibose, and salicinol, as reference compounds. The crystal structure T. maritima α-glucanotransferase (PDB code: 1LWJ) can be employed to serve as the template in the virtual screening of S. cerevisiae α-glucosidase. The comparison between the binding pocket residues of Thermotoga maritima α-glucanotransferase and Saccharomyces cerevisiae α-glucosidase show a high sequence identity and similarity. The result showed that sulochrin could be located in the binding pocket and formed some interactions with the binding residues. The ligands showed proper predicted binding energy (-6.74 - -4.13 kcal/mol) and predicted Ki values (0.011 - 0.939 mM). Sulochrin has a possibility to serve as a lead compound in the development of new α-glucosidase inhibitor.   Keywords: Docking, sulochrin, α-glucosidase Inhibitor, Thermotoga maritime α-glucotransferase, Saccharomyces cerevisiae α-glucosidase, MOE


2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Morgan Milton ◽  
Richard Honzatko ◽  
Scott Nelson

Author(s):  
John S. Sack ◽  
Mian Gao ◽  
Susan E. Kiefer ◽  
Joseph E. Myers ◽  
John A. Newitt ◽  
...  

Microtubule-associated protein/microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine kinase involved in the phosphorylation of MAP proteins that regulate microtubule dynamics. Abnormal activity of MARK4 has been proposed to contribute to neurofibrillary tangle formation in Alzheimer's disease. The crystal structure of the catalytic and ubiquitin-associated domains of MARK4 with a potent pyrazolopyrimidine inhibitor has been determined to 2.8 Å resolution with anRworkof 22.8%. The overall structure of MARK4 is similar to those of the other known MARK isoforms. The inhibitor is located in the ATP-binding site, with the pyrazolopyrimidine group interacting with the inter-lobe hinge region while the aminocyclohexane moiety interacts with the catalytic loop and the DFG motif, forcing the activation loop out of the ATP-binding pocket.


2018 ◽  
Vol 115 (52) ◽  
pp. 13264-13269 ◽  
Author(s):  
Jie Yin ◽  
Karen Chapman ◽  
Lindsay D. Clark ◽  
Zhenhua Shao ◽  
Dominika Borek ◽  
...  

The NK1 tachykinin G-protein–coupled receptor (GPCR) binds substance P, the first neuropeptide to be discovered in mammals. Through activation of NK1R, substance P modulates a wide variety of physiological and disease processes including nociception, inflammation, and depression. Human NK1R (hNK1R) modulators have shown promise in clinical trials for migraine, depression, and emesis. However, the only currently approved drugs targeting hNK1R are inhibitors for chemotherapy-induced nausea and vomiting (CINV). To better understand the molecular basis of ligand recognition and selectivity, we solved the crystal structure of hNK1R bound to the inhibitor L760735, a close analog of the drug aprepitant. Our crystal structure reveals the basis for antagonist interaction in the deep and narrow orthosteric pocket of the receptor. We used our structure as a template for computational docking and molecular-dynamics simulations to dissect the energetic importance of binding pocket interactions and model the binding of aprepitant. The structure of hNK1R is a valuable tool in the further development of tachykinin receptor modulators for multiple clinical applications.


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