scholarly journals An In-Silico Study of Stable and Environment-Friendly Oryza sativa Urease

2020 ◽  
Vol 11 (3) ◽  
pp. 10238-10247

Urea is one of the most extensively used fertilizers in agriculture but has a detrimental impact on the environment. One of the strategies to reduce this impact can be engineering modified plants containing urease enzyme with a considerably higher affinity for urea so that the urea applied in the fields can be significantly reduced. In this study, we have selected Oryza sativa Urease and generated stable mutants having a high affinity for urea. We modeled the 3D structure of the enzyme and identified the potential binding sites by analyzing the binding sites of similar proteins, i.e., 48 urea binding proteins. We found that mutation of Arg578 with Cys near the substrate-binding site of Oryza sativa Urease leads to a stable mutant protein that has a higher binding affinity for urea. This study will lead to a generation of environment-friendly, stable, genetically modified rice crop that consumes lesser urea, without compromising with crop productivity.

Author(s):  
Surendran Vijayaraj ◽  
Kannekanti Chaithanya Veena

Objective: Objective of the study is to perform a molecular docking analysis of novel oxime prodrug of gliclazide against SUR1 receptor.Methods: Sulfonylurea receptors (SUR) are membrane proteins which are the molecular targets of the sulfonylurea class of anti-diabetic drugs whose mechanism of action is to promote insulin release from pancreatic beta cells. Oxime prodrug of gliclazide a better soluble derivative of gliclazide is used for enhancement of bioavailability of gliclazide. Autodock 4.2 software was used for docking studies. Ligand 2D structures were drawn using ChemDraw Ultra 7.0. Binding sites, docking poses and interactions of the ligand with SUR1 receptors were studied by pymol software.Results: The docking studies suggest that potential binding sites of oxime prodrug of gliclazide exhibiting all the major interactions such as hydrogen bonding, hydrophobic interaction and electrostatic interaction with GLU43, LEU11, LEU 40, ILE17 GLU 68, GLN72 residues of SUR1. The binding energy of complexes are also found to be minimal forming stable complexes.Conclusion: In silico study of oxime prodrug of gliclazide conforms, the binding of oxime prodrug of glicalzide with SUR1 receptors which effectively controls the release insulin to regulate plasma glucose concentrations. Hence, the oxime prodrug of gliclazide could be a potent anti-diabetic target molecule which may be worth for further in vitro and in vivostudies. 


2021 ◽  
Vol 120 (3) ◽  
pp. 219a
Author(s):  
Claire Albrecht ◽  
Brett A. Israels ◽  
Chloe Chvatal ◽  
Peter H. von Hippel ◽  
Andrew H. Marcus

1985 ◽  
Vol 229 (3) ◽  
pp. 687-692 ◽  
Author(s):  
F Tabary ◽  
J P Frénoy

The interaction of lectin isolated from rice (Oryza sativa) embryos with N-acetylglucosaminides was studied by equilibrium dialysis and fluorescence. Equilibrium dialysis with 4-methylumbelliferyl-(GlcNac)2 showed that rice lectin (Mr 38000) contains four equivalent saccharide-binding sites. Addition of the N-acetylglucosaminides GlcNac, (GlcNac)2 and (GlcNac)3 enhanced the intrinsic fluorescence of rice lectin and this was accompanied by a 10nm blue-shift of its maximum fluorescence with (GlcNac)2 and (GlcNac)3. These changes in intensity allowed determination of the association constants, which increased with the number of saccharide units: at 20 degrees C, Ka = (1.3 +/- 0.1) X 10(3), (5.1 +/- 0.4) X 10(4) and (2.6 +/- 0.1) X 10(5) M−1 for GlcNac, (GlcNac)2 and (GlcNac)3 respectively. The binding enthalpy, delta H0, for the three glucosaminides were very low and ranged from −12.1 to −20.6 kJ X mol-1. The results are compared with those obtained with wheat-germ agglutinin, another GlcNac-specific gramineaous lectin.


Author(s):  
Nurbubu T. Moldogazieva ◽  
Daria S. Ostroverkhova ◽  
Nikolai N. Kuzmich ◽  
Vladimir V. Kadochnikov ◽  
Alexander A. Terentiev ◽  
...  

Alpha-fetoprotein (AFP) is a major embryo- and tumor-associated protein capable of binding and transporting variety of hydrophobic ligands including estrogens. AFP has been shown to inhibit estrogen receptor (ER)-positive tumor growth and this can be attributed to its estrogen-binding ability. Despite AFP has long been investigated, its three-dimensional (3D) structure has not been experimentally resolved and molecular mechanisms underlying AFP-ligand interaction remain obscure. In our study we constructed homology-based 3D model of human AFP (HAFP) with the purpose to perform docking of ERα ligands, three agonists (17β-estradiol, estrone and diethylstilbestrol) and three antagonists (tamoxifen, afimoxifene and endoxifen) into the obtained structure. Based on ligand docked scoring function, we identified three putative estrogen- and antiestrogen-binding sites with different ligand binding affinities. Two high-affinity sites were located in (i) a tunnel formed within HAFP subdomains IB and IIA and (ii) opposite side of the molecule in a groove originating from cavity formed between domains I and III, while (iii) the third low-affinity site was found at the bottom of the cavity. 100 ns MD simulation allowed studying their geometries and showed that HAFP-estrogen interactions occur due to van der Waals forces, while both hydrophobic and electrostatic interactions were almost equally involved in HAFP-antiestrogen binding. MM/GBSA rescoring method estimated binding free energies (ΔGbind) and showed that antiestrogens have higher affinities to HAFP as compared to estrogens. We performed in silico point substitutions of amino acid residues to confirm their roles in HAFP-ligand interactions and showed that Thr132, Leu138, His170, Phe172, Ser217, Gln221, His266, His316, Lys453, and Asp478 residues along two disulfide bonds, Cys224-Cys270 and Cys269-Cys277 have key roles in both HAFP-estrogen and HAFP-antiestrogen binding. Data obtained in our study contribute to understanding mechanisms underlying protein-ligand interactions and anti-cancer therapy strategies based on ER-binding ligands.


Zebra fish has long been considered to be as a strong animal model in biology and modern genetics; however now a days its gaining lot of importance in environmental studies as well. The readily availability of entire genome sequences made to permit carrying out in silico studies at Genomic level. As everyone is known that stress is much more complex and complicated process that involves so much of gene regulations known as up regulation and down regulation, the corresponding stress proteins, broadly known as heat shock proteins. In the current study, the potential transcription factor binding sites were traced out by using bioinformatics tools and about 50 heat shock protein genes were predicted by using special alogorithms using pattern matching and position weight matrices. The 3D structure of DNA-binding domain of HSTF-1 ( Heat Shock Transcription factor-1) which is crucial for regulating heat shot proteins was traced out and builted by using homology modelling methods. The 3D structure of the heat shock transcription factor-1 and together with predicted transcription factor binding sites may be validated in future experimental works which would help us in understanding the complex responsive stress mechanisms lying in Zebra fish.


Plant Gene ◽  
2019 ◽  
Vol 19 ◽  
pp. 100189 ◽  
Author(s):  
Parviz Heidari ◽  
Mostafa Ahmadizadeh ◽  
Fatemeh Izanlo ◽  
Thomas Nussbaumer

2019 ◽  
Vol 20 (24) ◽  
pp. 6218 ◽  
Author(s):  
Joseph T. Ortega ◽  
Beata Jastrzebska

G protein-coupled receptors (GPCRs) play a predominant role in the drug discovery effort. These cell surface receptors are activated by a variety of specific ligands that bind to the orthosteric binding pocket located in the extracellular part of the receptor. In addition, the potential binding sites located on the surface of the receptor enable their allosteric modulation with critical consequences for their function and pharmacology. For decades, drug discovery focused on targeting the GPCR orthosteric binding sites. However, finding that GPCRs can be modulated allosterically opened a new venue for developing novel pharmacological modulators with higher specificity. Alternatively, focus on discovering of non-retinoid small molecules beneficial in retinopathies associated with mutations in rhodopsin is currently a fast-growing pharmacological field. In this review, we summarize the accumulated knowledge on retinoid ligands and non-retinoid modulators of the light-sensing GPCR, rhodopsin and their potential in combating the specific vision-related pathologies. Also, recent findings reporting the potential of biologically active compounds derived from natural products as potent rod opsin modulators with beneficial effects against degenerative diseases related to this receptor are highlighted here.


2020 ◽  
Vol 21 (3) ◽  
pp. 893 ◽  
Author(s):  
Nurbubu T. Moldogazieva ◽  
Daria S. Ostroverkhova ◽  
Nikolai N. Kuzmich ◽  
Vladimir V. Kadochnikov ◽  
Alexander A. Terentiev ◽  
...  

Alpha-fetoprotein (AFP) is a major embryo- and tumor-associated protein capable of binding and transporting a variety of hydrophobic ligands, including estrogens. AFP has been shown to inhibit estrogen receptor (ER)-positive tumor growth, which can be attributed to its estrogen-binding ability. Despite AFP having long been investigated, its three-dimensional (3D) structure has not been experimentally resolved and molecular mechanisms underlying AFP–ligand interaction remains obscure. In our study, we constructed a homology-based 3D model of human AFP (HAFP) with the purpose of molecular docking of ERα ligands, three agonists (17β-estradiol, estrone and diethylstilbestrol), and three antagonists (tamoxifen, afimoxifene and endoxifen) into the obtained structure. Based on the ligand-docked scoring functions, we identified three putative estrogen- and antiestrogen-binding sites with different ligand binding affinities. Two high-affinity binding sites were located (i) in a tunnel formed within HAFP subdomains IB and IIA and (ii) on the opposite side of the molecule in a groove originating from a cavity formed between domains I and III, while (iii) the third low-affinity binding site was found at the bottom of the cavity. Here, 100 ns molecular dynamics (MD) simulation allowed us to study their geometries and showed that HAFP–estrogen interactions were caused by van der Waals forces, while both hydrophobic and electrostatic interactions were almost equally involved in HAFP–antiestrogen binding. Molecular mechanics/Generalized Born surface area (MM/GBSA) rescoring method exploited for estimation of binding free energies (ΔGbind) showed that antiestrogens have higher affinities to HAFP as compared to estrogens. We performed in silico point substitutions of amino acid residues to confirm their roles in HAFP–ligand interactions and showed that Thr132, Leu138, His170, Phe172, Ser217, Gln221, His266, His316, Lys453, and Asp478 residues, along with two disulfide bonds (Cys224–Cys270 and Cys269–Cys277), have key roles in both HAFP–estrogen and HAFP–antiestrogen binding. Data obtained in our study contribute to understanding mechanisms underlying protein–ligand interactions and anticancer therapy strategies based on ERα-binding ligands.


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