scholarly journals Calculation and Comparison of Energy Interaction and Intensity Parameters for the Interaction of Nd(III) with DL-Valine, DL-Alanine and β-Alanine in Presence and Absence of Ca2+/Zn2+ in Aqueous and Different Aquated Organic Solvents Using 4f-4f Transition Spectra as Probe

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
H. Debecca Devi ◽  
Ch. Sumitra ◽  
Th. David Singh ◽  
N. Yaiphaba ◽  
N. Mohondas Singh ◽  
...  
Keyword(s):  
Amino Acids ◽  
Oscillator Strength ◽  
Organic Solvents ◽  
Electric Dipole ◽  
Spectral Energy ◽  
Ligand Interaction ◽  
Energy Parameters ◽  
Energy Interaction ◽  
Intensity Parameters ◽  
Presence And Absence

Absorption difference and comparative absorption spectrophotometric studies involving 4f-4f transitions of Nd(III) and different amino acids: DL-valine, DL-alanine, and β-alanine in presence and absence of Ca(II) and Zn(II) in aqueous and different aquated organic solvents have been carried out. Variations in the spectral energy parameters: Slater-Condon (FK) factor, Racah (EK), Lande factor (ξ4f), nephelauxetic ratio (β), bonding (b1/2), percentage covalency (δ) are calculated to explore the mode of interaction of Nd(III) with different amino acids: DL-valine, DL-alanine, and β-alanine. The values of experimentally calculated oscillator strength (P) and computed values of Judd-Ofelt electric dipole intensity parameters, Tλ (λ = 2,4,6), are also determined for different 4f-4f transitions. The variation in the values of P and Tλ parameters explicitly shows the relative sensitivities of the 4f-4f transitions as well as the specific correlation between relative intensities, ligand structures, and nature of Nd(III)-ligand interaction.

Lasing Efficiency of Nd3+-Doped Lead Tellurite Glass

2017 ◽  
Vol 268 ◽  
pp. 186-190
Author(s):  
K. Azman ◽  
Yahya Norihan ◽  
H. Azhan ◽  
S. Akmal Syamsyir ◽  
R.S. Nasuha
Keyword(s):  
Oscillator Strength ◽  
Electric Dipole ◽  
Tellurite Glass ◽  
Optical Behaviour ◽  
Ofelt Theory ◽  
Laser Efficiency ◽  
Lasing Efficiency ◽  
Optical Amplification ◽  
Intensity Parameters

Neodymium doped tellurite glass have been proven to be one of the most efficient candidates for photonic application. Nd3+ ions are well known excellent as lasing ions at 1.06μm. However, the efficiency of the lasing activity of the Nd3+ doped tellurite glass need for more discussion especially on the contribution of the atom-atom and atom-ligand bonding based on the Judd-Ofelt theory. Therefore, initiative has been taken in this work to determine the laser efficiency by mean of their oscillator strength and Judd-Ofelt parameters. In order to identify the optical behaviour, good quality of Nd doped tellurite glass should firstly be ready. From the results, it is found that the experimental and calculated oscillator strength results of the glass are found varies from 1.157 x 10-6 to 0.804 x 10-6 and from 2.527 x 10-6 to 2.243 x 10-6 respectively with respect to Nd2O3 composition. The small rms deviation ~10% indicates good fit between experimental and calculated oscillator strength. Meanwhile, the Judd-Ofelt intensity parameters with t = 2, 4 and 6 are found to vary with respect to mol% of Nd content. The 4F3/2→4I11/2 transition for 1.06μm emission which is useful for lasers and optical amplification is totally contributed from electric dipole whereas the magnetic dipole shows no effect. Some other results will be discussed in details.

Inference of the solvation energy parameters of amino acids using maximum entropy approach

2008 ◽  
Vol 129 (3) ◽  
pp. 035102 ◽  
Author(s):  
Trinh X. Hoang ◽  
Flavio Seno ◽  
Antonio Trovato ◽  
Jayanth R. Banavar ◽  
Amos Maritan
Keyword(s):  
Amino Acids ◽  
Maximum Entropy ◽  
Solvation Energy ◽  
Energy Parameters

scholarly journals Whole Genome Sequence Analysis and Homology Modelling of a 3C Like Peptidase and a Non-Structural Protein 3 of the SARS-CoV-2 Shows Protein Ligand Interaction with an Aza-Peptide and a Noncovalent Lead Inhibitor with Possible Antiviral Properties

2020 ◽  
Author(s):  
Arun Shanker ◽  
Divya Bhanu ◽  
Anjani Alluri
Keyword(s):  
Amino Acids ◽  
Binding Sites ◽  
Tertiary Structure ◽  
Vaccine Development ◽  
Homology Modelling ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Structural Protein ◽  
Ligand Interaction ◽  
Percent Identity

<p></p><p>The family of viruses belonging to Coronaviridae mainly consist of virulent pathogens that have a zoonotic property, Severe Acute Respiratory Syndrome (SARS-CoV) and Middle East Respiratory Syndrome (MERS-CoV) of this family have emerged before and now the SARS-CoV-2 has emerged in China. Characterization of spike glycoproteins, polyproteins and other viral proteins from viruses are important for vaccine development. Homology modelling of these proteins with known templates offers the opportunity to discover ligand binding sites and explore the possible antiviral properties of these protein ligand complexes. Any information emerging from these protein models can be used for vaccine development. In this study we did a complete bioinformatic analysis, sequence alignment, comparison of multiple sequences and homology modelling of the <a>SARS-CoV-2 </a>whole genome sequences, the spike protein and the polyproteins for homology with known proteins, we also analysed receptor binding sites in these models for possible binding with ligands that exhibit antiviral properties. Our results showed that the tertiary structure of the polyprotein isolate SARS-CoV-2_HKU-SZ-001_2020 had 98.94 percent identity with SARS-Coronavirus NSP12 bound to NSP7 and NSP8 co-factors. <a>Our results indicate that a part of the viral genome </a><a>(residues 3268 -3573 in Frame 2 with 306 amino acids) of the SARS-CoV-2 virus isolate Wuhan-Hu-1 (Genbank Accession Number MN908947.3) </a>when modelled with template 2a5i of the PDB database had 96 percent identity with a 3C like peptidase of SARS-CoV which has ability to bind with Aza-Peptide Epoxide (APE) which is known for irreversible inhibition of SARS-CoV main peptidase. The part of the genome (residues 1568-1882 in Frame 2 with 315 amino acids) when modelled with template 3e9s of the PDB database had 82 percent identity with a papain-like protease/deubiquitinase which when complexed with ligand GRL0617 acts as inhibitor which can block SARS-CoV replication. The regions studied was conserved in more than 90 genomes of SARS-CoV-2. It is possible that these viral inhibiters can be used for vaccine development for the SARS-CoV-2.</p><p></p><p></p>

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