scholarly journals ANTIFUNGAL PROPERTIES OF SECONDARY METABOLITES OF AZADIRACHTA INDICA AND LAWSONIA INERMIS – AN IN SILICO STUDY

Author(s):  
Simhadri Vsdna Nagesh ◽  
Muniappan M ◽  
Kannan I ◽  
Viswanathan S

Objective: This study was aimed to inhibit the sulfite reductase using naturally obtained secondary metabolites of common plants Azadirachta indica and Lawsonia inermis.Methods: The active ingredients of neem and henna were selected and the.sdf files of these were downloaded from PubChem database. Converted the.sdf files to.pdb files with the help of OPENBABEL software which is prerequisite to dock. The three-dimensional structure was incurred from the template of homology of sulfite reductase using MODELLAR software version 9.0. Docking of sulfite reductase with the ligands was performed using iGEMDOCK and Autodock Vina softwares. The physicochemical, pharmacokinetic, drug-likeness, lead-likeness, and toxicological properties were obtained by SWISSADME and admetSAR online tools.Results: The active ingredients show an excellent affinity with the sulfite reductase which obtained was tabulated and the significant properties of a ligand were showing that these can be an investigational new drug entity.Conclusion: In this research, it can concluded that the secondary metabolites obtained from plants were inhibiting the induction of sulfite reductase thereby inhibiting Sulfite Assimilation Pathway leads to commove the amino acid metabolism of organism which shows unique in fungi.

2020 ◽  
Vol 1 (1) ◽  
pp. 21-36
Author(s):  
Adoum Mahamat Baraka ◽  
Kanita Šabanović ◽  
Mohamed Ragab Abdel Gawwad

Arabidopsis thaliana genome encodes two POLE2 homologs known as polymerase epsilon catalytic subunit A (POLE2A) and polymerase epsilon catalytic subunit B (POLE2B). They play a very important role in DNA repair mechanisms. In this study, bioinformatics tools were used to understand DNA repair mechanisms in A. thaliana in which POLE2A and POLE2B proteins are involved. Through interactome analysis of POLE2A and POLE2B homolog proteins in A. thaliana, their additional roles in DNA repair were explored. The most important proteins that are participating in DNA repairs,  like MSH2, MSH5, PCNA1, PCNA2, PRL, and CDC45 were identified as interactors of both POLE2A and POLE2B. The three-dimensional structure of POLE2 proteins was identified to decipher the complexity of NER, GG-NER, MMR, TFIIH, and TC-NER repair mechanisms through the identification of docking sites. The interaction complex of POLE2A and POLE2B with six proteins was confirmed and found to have a significant role in DNA repair processes and UV-B tolerance. The interactome analysis of POLE2A and POLE2B performed here once again confirms the complexity of the DNA repair mechanism in plants.


Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.


Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.


Author(s):  
T.D. Pollard ◽  
P. Maupin

In this paper we review some of the contributions that electron microscopy has made to the analysis of actin and myosin from nonmuscle cells. We place particular emphasis upon the limitations of the ultrastructural techniques used to study these cytoplasmic contractile proteins, because it is not widely recognized how difficult it is to preserve these elements of the cytoplasmic matrix for electron microscopy. The structure of actin filaments is well preserved for electron microscope observation by negative staining with uranyl acetate (Figure 1). In fact, to a resolution of about 3nm the three-dimensional structure of actin filaments determined by computer image processing of electron micrographs of negatively stained specimens (Moore et al., 1970) is indistinguishable from the structure revealed by X-ray diffraction of living muscle.


Author(s):  
J.L. Williams ◽  
K. Heathcote ◽  
E.J. Greer

High Voltage Electron Microscope already offers exciting experimental possibilities to Biologists and Materials Scientists because the increased specimen thickness allows direct observation of three dimensional structure and dynamic experiments on effectively bulk specimens. This microscope is designed to give maximum accessibility and space in the specimen region for the special stages which are required. At the same time it provides an ease of operation similar to a conventional instrument.


Author(s):  
G. E. Tyson ◽  
M. J. Song

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.


Author(s):  
Jerome J. Paulin

Within the past decade it has become apparent that HVEM offers the biologist a means to explore the three-dimensional structure of cells and/or organelles. Stereo-imaging of thick sections (e.g. 0.25-10 μm) not only reveals anatomical features of cellular components, but also reduces errors of interpretation associated with overlap of structures seen in thick sections. Concomitant with stereo-imaging techniques conventional serial Sectioning methods developed with thin sections have been adopted to serial thick sections (≥ 0.25 μm). Three-dimensional reconstructions of the chondriome of several species of trypanosomatid flagellates have been made from tracings of mitochondrial profiles on cellulose acetate sheets. The sheets are flooded with acetone, gluing them together, and the model sawed from the composite and redrawn.The extensive mitochondrial reticulum can be seen in consecutive thick sections of (0.25 μm thick) Crithidia fasciculata (Figs. 1-2). Profiles of the mitochondrion are distinguishable from the anterior apex of the cell (small arrow, Fig. 1) to the posterior pole (small arrow, Fig. 2).


Author(s):  
Kenneth H. Downing ◽  
Hu Meisheng ◽  
Hans-Rudolf Went ◽  
Michael A. O'Keefe

With current advances in electron microscope design, high resolution electron microscopy has become routine, and point resolutions of better than 2Å have been obtained in images of many inorganic crystals. Although this resolution is sufficient to resolve interatomic spacings, interpretation generally requires comparison of experimental images with calculations. Since the images are two-dimensional representations of projections of the full three-dimensional structure, information is invariably lost in the overlapping images of atoms at various heights. The technique of electron crystallography, in which information from several views of a crystal is combined, has been developed to obtain three-dimensional information on proteins. The resolution in images of proteins is severely limited by effects of radiation damage. In principle, atomic-resolution, 3D reconstructions should be obtainable from specimens that are resistant to damage. The most serious problem would appear to be in obtaining high-resolution images from areas that are thin enough that dynamical scattering effects can be ignored.


Author(s):  
J.S. Wall ◽  
V. Maridiyan ◽  
S. Tumminia ◽  
J. Hairifeld ◽  
M. Boublik

The high contrast in the dark-field mode of dedicated STEM, specimen deposition by the wet film technique and low radiation dose (1 e/Å2) at -160°C make it possible to obtain high resolution images of unstained freeze-dried macromolecules with minimal structural distortion. Since the image intensity is directly related to the local projected mass of the specimen it became feasible to determine the molecular mass and mass distribution within individual macromolecules and from these data to calculate the linear density (M/L) and the radii of gyration.2 This parameter (RQ), reflecting the three-dimensional structure of the macromolecular particles in solution, has been applied to monitor the conformational transitions in E. coli 16S and 23S ribosomal RNAs in solutions of various ionic strength.In spite of the differences in mass (550 kD and 1050 kD, respectively), both 16S and 23S RNA appear equally sensitive to changes in buffer conditions. In deionized water or conditions of extremely low ionic strength both appear as filamentous structures (Fig. la and 2a, respectively) possessing a major backbone with protruding branches which are more frequent and more complex in 23S RNA (Fig. 2a).


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