scholarly journals Antisense Peptide Technology for Diagnostic Tests and Bioengineering Research

2021 ◽  
Vol 22 (17) ◽  
pp. 9106
Author(s):  
Nikola Štambuk ◽  
Paško Konjevoda ◽  
Josip Pavan
Keyword(s):  
Amino Acids ◽  
Diagnostic Tests ◽  
Peptide Design ◽  
Receptor Binding Domain ◽  
Standard Genetic Code ◽  
Random Peptide ◽  
Code Table ◽  
Complementary Sense ◽  
Peptide Interaction ◽  
Antisense Peptide

Antisense peptide technology (APT) is based on a useful heuristic algorithm for rational peptide design. It was deduced from empirical observations that peptides consisting of complementary (sense and antisense) amino acids interact with higher probability and affinity than the randomly selected ones. This phenomenon is closely related to the structure of the standard genetic code table, and at the same time, is unrelated to the direction of its codon sequence translation. The concept of complementary peptide interaction is discussed, and its possible applications to diagnostic tests and bioengineering research are summarized. Problems and difficulties that may arise using APT are discussed, and possible solutions are proposed. The methodology was tested on the example of SARS-CoV-2. It is shown that the CABS-dock server accurately predicts the binding of antisense peptides to the SARS-CoV-2 receptor binding domain without requiring predefinition of the binding site. It is concluded that the benefits of APT outweigh the costs of random peptide screening and could lead to considerable savings in time and resources, especially if combined with other computational and immunochemical methods.

scholarly journals Golden and Harmonic Mean in the Genetic Code

2017 ◽  
Author(s):  
Miloje M. Rakocevic
Keyword(s):  
Amino Acids ◽  
Genetic Code ◽  
Harmonic Mean ◽  
Standard Genetic Code ◽  
Code Table ◽  
Nucleotide Triplet

In previous two works [1], [2] we have shown the determination of genetic code by golden and harmonic mean within standard Genetic Code Table, i.e. nucleotide triplet table, whereas in this paper we show the same determination through a specific connection between two tables – of nucleotide doublets Table and triplets Table, over polarity of amino acids, measured by Cloister energy.

scholarly journals Golden and Harmonic Mean in the Genetic Code

2017 ◽  
Author(s):  
Miloje M. Rakocevic
Keyword(s):  
Amino Acids ◽  
Genetic Code ◽  
Harmonic Mean ◽  
Standard Genetic Code ◽  
International Conference ◽  
Theoretical Approaches ◽  
Code Table ◽  
Nucleotide Triplet ◽  
Polar Requirement

In previous two works (Rakočević, 1998; 2013), we have shown the determination of genetic code by golden and harmonic mean within standard Genetic Code Table, i.e. nucleotide triplet table, whereas in this paper we show the same determination through a specific connection between two tables – of nucleotide doublets Table and triplets Table, over polarity of amino acids, measured by Cloister energy in general, and by hydropathy and polar requirement, partialy. [This is the expanded version of the article published in Proceedings of the 2nd International Conference “Theoretical Approaches to BioInformation Systems” (TABIS.2013), September 17–22, 2013, Belgrade, Serbia. That first version is also stored, as Version 1, in OSF Preprints.]

scholarly journals Gonococcal pili. Primary structure and receptor binding domain.

1984 ◽  
Vol 159 (5) ◽  
pp. 1351-1370 ◽  
Author(s):  
G K Schoolnik ◽  
R Fernandez ◽  
J Y Tai ◽  
J Rothbard ◽  
E C Gotschlich
Keyword(s):  
Amino Acids ◽  
Receptor Binding ◽  
Binding Domain ◽  
Structural Basis ◽  
Receptor Binding Domain ◽  
Variable Regions ◽  
Disulfide Linkage ◽  
Polymeric Structure ◽  
Antigenic Diversity ◽  
Single Polypeptide Chain

The complete amino acid sequence of pilin from gonococcal strain MS11 and the sequence of constant and variable regions from strain R10 pilin have been determined in order to elucidate the structural basis for adherence function, antigenic diversity, and polymeric structure. The MS11 pilin sequence consists of 159 amino acids in a single polypeptide chain with two cysteines in disulfide linkage and serine-bonded phosphate residues. TC-2 (31-111), a soluble monomeric pilus peptide prepared by arginine-specific digestion, bound human endocervical, but not buccal or HeLa cells and therefore is postulated to encompass the receptor binding domain. Variable regions of CNBr-3 appear to confer antigenic diversity and comprise segments in which changes in the position of charged residues occur in hydrophilic, beta-turns. Residues 2-21 and 202-221 of gonococcal pilins and lower eucaryotic actins, respectively, exhibit 50% homology. When these residues are arranged at intervals of 100 degrees of arc on "helical wheels," the identical amino acids comprise a hydrophobic face on one side of the helix. This observation, the hydrophobic character of this region and the tendency for TC-1 (residues 1-30) to aggregate in water, suggest that this stretch interacts with other subunits to stabilize polymeric structure.

scholarly journals Some theoretical aspects of reprogramming the standard genetic code

2020 ◽  
Author(s):  
Kuba Nowak ◽  
Paweł Błażej ◽  
Małgorzata Wnetrzak ◽  
Dorota Mackiewicz ◽  
Paweł Mackiewicz
Keyword(s):  
Amino Acids ◽  
Genetic Code ◽  
Dna Sequences ◽  
Theoretical Perspective ◽  
Optimal Number ◽  
Optimal Size ◽  
Coding System ◽  
Standard Genetic Code ◽  
Nucleotide Mutation ◽  
Code Extension

1AbstractReprogramming of the standard genetic code in order to include non-canonical amino acids (ncAAs) opens a new perspective in medicine, industry and biotechnology. There are several methods of engineering the code, which allow us for storing new genetic information in DNA sequences and transmitting it into the protein world. Here, we investigate the problem of optimal genetic code extension from theoretical perspective. We assume that the new coding system should encode both canonical and new ncAAs using 64 classical codons. What is more, the extended genetic code should be robust to point nucleotide mutation and minimize the possibility of reversion from new to old information. In order to do so, we follow graph theory to study the properties of optimal codon sets, which can encode 20 canonical amino acids and stop coding signal. Finally, we describe the set of vacant codons that could be assigned to new amino acids. Moreover, we discuss the optimal number of the newly incorporated ncAAs and also the optimal size of codon blocks that are assigned to ncAAs.

scholarly journals Possible Transmission Flow of SARS-CoV-2 Based on ACE2 Features

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5906
Author(s):  
Sk. Sarif Hassan ◽  
Shinjini Ghosh ◽  
Diksha Attrish ◽  
Pabitra Pal Choudhury ◽  
Alaa A. A. Aljabali ◽  
...  
Keyword(s):  
Amino Acids ◽  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Receptor Binding ◽  
Comprehensive Analysis ◽  
Cellular Receptor ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
Protein Receptor

Angiotensin-converting enzyme 2 (ACE2) is the cellular receptor for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is engendering the severe coronavirus disease 2019 (COVID-19) pandemic. The spike (S) protein receptor-binding domain (RBD) of SARS-CoV-2 binds to the three sub-domains viz. amino acids (aa) 22–42, aa 79–84, and aa 330–393 of ACE2 on human cells to initiate entry. It was reported earlier that the receptor utilization capacity of ACE2 proteins from different species, such as cats, chimpanzees, dogs, and cattle, are different. A comprehensive analysis of ACE2 receptors of nineteen species was carried out in this study, and the findings propose a possible SARS-CoV-2 transmission flow across these nineteen species.

Peptide Design Using ω-Amino Acids:  Unusual Turn Structures Nucleated by an N-Terminal Single γ-Aminobutyric Acid Residue in Short Model Peptides

2002 ◽  
Vol 67 (3) ◽  
pp. 633-639 ◽  
Author(s):  
Samir Kumar Maji ◽  
Rahul Banerjee ◽  
D. Velmurugan ◽  
A. Razak ◽  
H. K. Fun ◽  
...  
Keyword(s):  
Amino Acids ◽  
Aminobutyric Acid ◽  
Peptide Design ◽  
Model Peptides

scholarly journals Amino acids 484 and 494 of SARS-CoV-2 spike are hotspots of immune evasion affecting antibody but not ACE2 binding

2021 ◽  
Author(s):  
Marta Alenquer ◽  
Filipe Ferreira ◽  
Diana Lousa ◽  
Mariana Valério ◽  
Mónica Medina-Lopes ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Angiotensin Converting Enzyme ◽  
Immune Evasion ◽  
Neutralizing Antibodies ◽  
Receptor Binding Domain ◽  
Converting Enzyme ◽  
Antibody Neutralization ◽  
Angiotensin Converting Enzyme 2 ◽  
The Core

AbstractUnderstanding SARS-CoV-2 evolution and host immunity is critical to control COVID-19 pandemics. At the core is an arms-race between SARS-CoV-2 antibody and angiotensin-converting enzyme 2 (ACE2) recognition, a function of the viral protein spike and, predominantly, of its receptor-binding-domain (RBD). Mutations in spike impacting antibody or ACE2 binding are known, but the effect of mutation synergy is less explored. We engineered 22 spike-pseudotyped lentiviruses containing individual and combined mutations, and confirmed that E484K evades antibody neutralization elicited by infection or vaccination, a capacity augmented when complemented by K417N and N501Y mutations. In silico analysis provided an explanation for E484K immune evasion. E484 frequently engages in interactions with antibodies but not with ACE2. Importantly, we identified a novel amino acid of concern, S494, which shares a similar pattern. Using the already circulating mutation S494P, we found that it reduces antibody neutralization of convalescent sera. This amino acid emerges as an additional hotspot for immune evasion and a target for therapies, vaccines and diagnostics.One-Sentence SummaryAmino acids in SARS-CoV-2 spike protein implicated in immune evasion are biased for binding to neutralizing antibodies but dispensable for binding the host receptor angiotensin-converting enzyme 2.

scholarly journals Enhancement of SARS-CoV-2 Receptor Binding Domain -CR3022 Human Antibody Binding Affinity via in Silico Engineering Approach

2020 ◽  
Author(s):  
Fateme Sefid ◽  
Zahra Payandeh ◽  
Ghasem Azamirad ◽  
Behzad Mansoori ◽  
Behzad Baradaran ◽  
...  
Keyword(s):  
Amino Acids ◽  
Binding Affinity ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Affinity Maturation ◽  
Binding Domain ◽  
Human Antibody ◽  
Receptor Binding Domain ◽  
Receptor Binding Site ◽  
Specificity And Sensitivity

Abstract Background: The nCoV-2019 is a cause of COVID-19 disease. The surface spike glycoprotein (S), which is necessary for virus entry through the intervention of the host receptor and it mediates virus-host membrane fusion, is the primary coronavirus antigen (Ag). The angiotensin-converting enzyme 2 (ACE2) is reported to be the effective human receptor for SARS-CoVs 2. ACE2 receptor can be prevented by neutralizing antibodies (nAbs) such as CR3022 targeting the virus receptor-binding site. Considering the importance of computational docking, and affinity maturation we aimed to find the important amino acids of the CR3022 antibody (Ab). These amino acids were then replaced by other amino acids to improve Ab-binding affinity to a receptor-binding domain (RBD) of the 2019-nCoV spike protein. Finally, we measured the binding affinity of Ab variants to the Ag. Result: Our findings disclosed that several variant mutations could successfully improve the characteristics of the Ab binding compared to the normal antibodies. Conclusion: The modified antibodies may be possible candidates for stronger affinity binding to Ags which in turn can affect the specificity and sensitivity of antibodies.

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