scholarly journals A STUDY ON SOME STRUCTURAL FEATURES RESPONSIBLE FOR SARS-COV-2 INFECTION FATALITY

2021 ◽  
Author(s):  
JAYDIP DATTA
Keyword(s):  
Molecular Weight ◽  
Biological Activities ◽  
Globular Proteins ◽  
Structural Features ◽  
Spike Protein ◽  
Radius Of Gyration ◽  
Fatality Rate ◽  
Hydrodynamic Properties ◽  
Standard Curve ◽  
Best Fit

In this article Covid19 is structurally analysed to establish the pathogenic attack through its spike protein ( 1 ) The most of the bio -macromolecules starting from globular proteins to viruses with a high molecular weight average showing polymeric nature as to induce their biological activities. The tremendous infectivity mainly depends on one most important hydrodynamic properties like Zigzag nature of viral walk ( 2 ) for a specific molecular weight ( M ). Hydrodynamic s nature of mRNA –viruses like SARS-COV-2 is analysed to compute the random– zigzag motion ( 2,3) of the virus known as Radius of Gyration( Rg ) value of virus . For computation of Rg a standard curve( 4 )of Rg – M is statistically analysed with best fit regression analysis like Morgan – Morgan – Finney ( MMF ) ( 5 ) model . This zigzag – random walk ( 2 ) of SARS-COV-2 molecule computed from Rg value may be considered as fatality rate of infection ( 6 ).

Structural features of low-molecular-weight heparins affecting their affinity to antithrombin

2009 ◽  
Vol 102 (11) ◽  
pp. 865-873 ◽  
Author(s):  
Antonella Bisio ◽  
Davide Vecchietti ◽  
Laura Citterio ◽  
Marco Guerrini ◽  
Rahul Raman ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nmr Spectra ◽  
Biological Activities ◽  
Anticoagulant Activity ◽  
2D Nmr ◽  
Structural Features ◽  
Size Exclusion ◽  
Low Molecular Weight ◽  
Low Molecular Weight Heparins ◽  
2D Nmr Spectra

SummaryAs part of a more extensive investigation on structural features of different low-molecular-weight heparins (LMWHs) that can affect their biological activities, Enoxaparin,Tinzaparin and Dalteparin were characterised with regards to the distribution of different chain length oligosaccharides as determined by size-exclusion (SE) chromatography, as well as their structure as defined by 2D-NMR spectra (HSQC). The three LMWHs were also fractionated into high affinity (HA) and no affinity (NA) pools with regards to their ability to bind antithrombin (AT).The HA fractions were further subfractionated and characterised. For the parent LMWHs and selected fractions,molecular weight parameters were measured using a SE chromatographic system with a triple detector (TDA) to obtain absolute molecular weights. The SE chromatograms clearly indicate that Enoxaparin is consistently richer in shorter oligosaccharides than Tinzaparin and Dalteparin. Besides providing the content of terminal groups and individual glucosamine and uronic acid residues with different sulfate substituents, the HSQC-NMR spectra permitted us to evaluate and correlate the content of the pentasaccharide, AT-binding sequence A-G-A*-I-A (AT-bs) through quantification of signals of the disaccharide sequence G-A*.Whereas the percent content of HA species is approximately the same for the three LMWHs, substantial differences were observed for the chain distribution of AT-bs as a function of length, with the AT-bs being preferentially contained in the longest chains of each LMWH. The above information will be useful in establishing structure-activity relationships currently under way. This study is therefore critical for establishing correlations between structural features of LMWHs and their AT-mediated anticoagulant activity.

scholarly journals THE STRUCTURAL COMPUTATION OF SARS-COV- 2 : A LIMITATION

2021 ◽  
Author(s):  
JAYDIP DATTA
Keyword(s):  
Molecular Weight ◽  
Physical Property ◽  
Radius Of Gyration ◽  
Data Modelling ◽  
Input Output ◽  
Output Data ◽  
Statistical Computation ◽  
Best Fit

In this paper we will try to compute a most important bio-physical property of Covid19 as an analogy of other biopolymers ( 1,2 ) like proteins – viruses . Since Covid19 is also considered as one of the most fatal viral biopolymer under this pandemic phase an attempt has been made through statistical computation of best fit regression.( 3 ) An input -output data modelling of bi-variant study of Molecular Weight ( M ) – Radius of Gyration ( Rg )( 4 ) with standard coding ( 5 ) will be referred . Finally a limitation of statistical computation is discussed with reproducibility ( 6 ) of SARS – COV-2 mutants

scholarly journals MATHEMATICAL STATISTICS : AN APPLICATION BASED STATISTICS

2020 ◽  
Author(s):  
JAYDIP DATTA
Keyword(s):  
Analytical Chemistry ◽  
Molecular Weight ◽  
Experimental Finding ◽  
Polynomial Regression ◽  
Random Coil ◽  
Radius Of Gyration ◽  
Hydrodynamic Properties ◽  
Chemistry Teaching ◽  
Physico Chemical ◽  
Standard Software

The APPLICATION part to be noted as follows: 1. RANDOM COIL BIOPOLYMERS. 2. BACTERIAL GROWTH. 3. PHYSICO-CHEMICAL ANALYSIS / ANALYTICAL CHEMISTRY. It is an experimental finding between Physical Chemistry and Analytical Chemistry Teaching methods .CITATION -Datta, Jaydip & Chatterjee, S & Bhattacharya, T. (2015). HYDRODYNAMIC MODELLING OF BIOPOLYMERS : A CORRELATION APPRAOCH ( ISSN : 0020-3254 ). 87. 2016. 10.6084/m9.figshare.12167607. In the earlier work 1 by Datta et al the important hydrodynamic properties like radius of gyration (R g) and root mean square end to end separation (R rms) can be calculated through theknown value of molecular weight (M). The mathematical modelling was done by polynomial regression through a standard software like curve finder. The present work correlates the most important viscometric property , Diffusion coefficient (D) 2,3 with the same hydrodynamic properties like radius of gyration (R g) i.e. D (R g) of the biopolymers. It is expected that a bulky biopolymer of Random Coil with high molecular weight diffuse more slowly through a solvent than the Random Coil of low.

Circulating Activities During Constant Infusion of Heparin or a Low Molecular Weight Derivative (Enoxaparine): Failure to Demonstrate any Circadian Variations

1987 ◽  
Vol 58 (04) ◽  
pp. 1068-1072 ◽  
Author(s):  
P Toulon ◽  
J F Vitoux ◽  
C Leroy ◽  
T Lecomte ◽  
M Roncato ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Circadian Rhythm ◽  
Biological Activities ◽  
Constant Infusion ◽  
Low Molecular Weight ◽  
Circadian Variations ◽  
Heparin Cofactor Ii ◽  
Heparin Infusion ◽  
Chromogenic Assay ◽  
Heparin Affinity

SummaryWe compared in six patients successively treated with an unfractionated heparin (UFH) and a low molecular weight heparin (LMWH) the variations in plasma anti-Xa activity, measured in a chromogenic assay, during a 36 h constant infusion. The values varied in a wider range during UHF infusion, but remained in the therapeutic range except once in one patient. No circadian rhythm could be demonstrated in our six patients. LMWH infusion yielded very constant anti-Xa circulating activities. In both cases, there were no significant modifications of three proteins with high heparin affinity (antithrombin III, heparin cofactor II, histidine-rich glycoprotein).Our results suggest that the circadian rhythm of the biological activities previously observed in patients treated with constant heparin infusion using clotting method is due to other factors than heparin itself.

The Reactive Formation of Diblock Copolymer at a Polymer/Polymer Interface and its Effect on Interfacial Structure

2000 ◽  
Vol 629 ◽  
Author(s):  
Jonathan S. Schulze ◽  
Timothy P. Lodge ◽  
Christopher W. Macosko
Keyword(s):  
Molecular Weight ◽  
Interfacial Structure ◽  
Root Mean Square Roughness ◽  
Radius Of Gyration ◽  
Interfacial Region ◽  
Force Microscopy ◽  
Amino Terminal ◽  
Polymer Interface ◽  
Atomic Force ◽  
Time Required

ABSTRACTThe reaction of perdeuterated amino-terminal polystyrene (dPS-NH2) with anhydrideterminal poly(methyl methacrylate) (PMMA-anh) at a PS/PMMA interface has been observed with forward recoil spectrometry (FRES). Bilayer samples were constructed by placing thin films of PS containing ∼8.5 wt % dPS-NH2 on a PMMA-anh layer. Significant reaction was observed only after annealing the samples at 174°C for several hours, a time scale at least two orders of magnitude greater than the time required for the dPS-NH2 chains to diffuse through the bulk PS layer. The topography of the interfacial region as copolymer formed was measured using atomic force microscopy (AFM). Roughening of the PS/PMMA interface was observed to varying degrees in all annealed samples. Furthermore, the extent of this roughening was found to depend on the PS matrix molecular weight. Reaction in the samples with a high molecular weight PS matrix resulted in a root mean square roughness approximately equal to the radius of gyration Rg of the copolymer. However, approximately twice as much roughening was observed in the low molecular weight PS matrix. This study reveals how the molecular weight of one of the phases can affect the rate of reaction at a polymer/polymer interface.

Quantities Directly Measurable by Scattering

2018 ◽  
Author(s):  
Eaton E. Lattman ◽  
Thomas D. Grant ◽  
Edward H. Snell
Keyword(s):  
Molecular Weight ◽  
Particle Shape ◽  
Particle Surface ◽  
Scattering Data ◽  
Radius Of Gyration ◽  
Particle Volume ◽  
Particle Surface Area ◽  
Scattering Angle ◽  
Particle Dimension ◽  
Maximum Particle

In this chapter we note that solution scattering data can be divided into four regions. At zero scattering angle, the scattering provides information on molecular weight of the particle in solution. Beyond that, the scattering is influenced by the radius of gyration. As the scattering angle increases, the scattering is influenced by the particle shape, and finally by the interface with the particle and the solution. There are a number of important invariants that can be calculated directly from the data including molecular mass, radius of gyration, Porod invariant, particle volume, maximum particle dimension, particle surface area, correlation length, and volume of correlation. The meaning of these is described in turn along with their mathematical derivations.

scholarly journals Sphingolipids of Asteroidea and Holothuroidea: Structures and Biological Activities

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 330
Author(s):  
Timofey V. Malyarenko ◽  
Alla A. Kicha ◽  
Valentin A. Stonik ◽  
Natalia V. Ivanchina
Keyword(s):  
Marine Invertebrates ◽  
Biological Activities ◽  
Complete Information ◽  
Structural Features ◽  
Marine Organisms ◽  
Structural Components ◽  
Chemical Structures ◽  
The Past ◽  
Complex Lipids ◽  
Complex Sphingolipids

Sphingolipids are complex lipids widespread in nature as structural components of biomembranes. Commonly, the sphingolipids of marine organisms differ from those of terrestrial animals and plants. The gangliosides are the most complex sphingolipids characteristic of vertebrates that have been found in only the Echinodermata (echinoderms) phylum of invertebrates. Sphingolipids of the representatives of the Asteroidea and Holothuroidea classes are the most studied among all echinoderms. In this review, we have summarized the data on sphingolipids of these two classes of marine invertebrates over the past two decades. Recently established structures, properties, and peculiarities of biogenesis of ceramides, cerebrosides, and gangliosides from starfishes and holothurians are discussed. The purpose of this review is to provide the most complete information on the chemical structures, structural features, and biological activities of sphingolipids of the Asteroidea and Holothuroidea classes.

Functional design of glycan-conjugated molecules using a chemoenzymatic approach

2021 ◽  
Author(s):  
Makoto Ogata
Keyword(s):  
Molecular Weight ◽  
Large Scale ◽  
Biological Activities ◽  
Natural Compounds ◽  
Low Molecular Weight ◽  
Functional Design ◽  
Enzymatic Method ◽  
Conjugated Molecules ◽  
Design Synthesis ◽  
And Function

Abstract Carbohydrates play important and diverse roles in the fundamental processes of life. We have established a method for accurately and a large scale synthesis of functional carbohydrates with diverse properties using a unique enzymatic method. Furthermore, various artificial glycan-conjugated molecules have been developed by adding these synthetic carbohydrates to macromolecules and to middle and low molecular weight molecules with different properties. These glycan-conjugated molecules have biological activities comparable to or higher than those of natural compounds, and present unique functions. In this review, several synthetic glycan-conjugated molecules are taken as examples to show design, synthesis and function.

scholarly journals Self-Stable Precipitation Polymerization Molecular Entanglement Effect and Molecular Weight Simulations and Experiments

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2243
Author(s):  
Jiali Qu ◽  
Yi Gao ◽  
Wantai Yang
Keyword(s):  
Molecular Weight ◽  
Maleic Anhydride ◽  
Molecular Conformation ◽  
Average Molecular Weight ◽  
Precipitation Polymerization ◽  
Radius Of Gyration ◽  
Propagation Mechanism ◽  
Reactive Molecular Dynamics ◽  
End Distance ◽  
Good Agreement

In this paper, we developed a reactive molecular dynamics (RMD) scheme to simulate the Self-Stable Precipitation (SP) polymerization of 1-pentene and cyclopentene (C5) with maleic anhydride (MAn) in an all-atom resolution. We studied the chain propagation mechanism by tracking the changes in molecular conformation and analyzing end-to-end distance and radius of gyration. The results show that the main reason of chain termination in the reaction process was due to intramolecular cyclic entanglement, which made the active center wrapped in the center of the globular chain. After conducting the experiment in the same condition with the simulation, we found that the distribution trend and peak value of the molecular-weight-distribution curve in the simulation were consistent with experimental results. The simulated number average molecular weight (Mn) and weight average molecular weight (Mw) were in good agreement with the experiment. Moreover, the simulated molecular polydispersity index (PDI) for cyclopentene reaction with maleic anhydride was accurate, differing by 0.04 from the experimental value. These show that this model is suitable for C5–maleic anhydride self-stable precipitation polymerization and is expected to be used as a molecular weight prediction tool for other maleic anhydride self-stable precipitation polymerization system.

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