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Nanomedicine Against COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Saima Zulfiqar, Zunaira Naeem, Shahzad Sharif, Ayoub Rashid Ch., M. Zia-Ul-Haq, Marius Moga
In biomedical applications such as diagnostics, therapeutics, safety/security, and environmental monitoring, grapheme, and dichalcogenides of transition metals have much importance. Pristine graphene is being used in biosensors, while its derivatives in detection and disinfection of microbes and enzyme assay [196, 197]. In the last decade, it was used for the first time to investigate the activity of enzymes, inhibition of viral helicase [198].
Nucleic Acids as Therapeutic Targets and Agents
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
There is now significant research activity in the DNA quadruplex area both in the biology of quadruplex and in drug discovery. In the former, researchers are exploring where and why quadruplexes form in the genome and what their functions are. For example, a number of naturally occurring proteins such as the helicases have been identified that can selectively bind to G-quadruplexes and unwind them. Interestingly, these helicases have been implicated in diseases such as Bloom’s and Werner’s syndromes. Researchers have also created an artificially derived zinc finger protein, Gq1, that is specific for G-quadruplexes, and a number of antibodies are under development.
Antibiotics: The Need for Innovation
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Protein synthesis is orchestrated by the cell’s DNA. An enzyme called DNA helicase separates the strands at a specific region on the DNA molecule; the gene containing the instruction for a specific protein, such as those like β-lactamase, which give rise to resistance. DNA helicase breaks the hydrogen bonds between the DNA bases, enabling another enzyme, called RNA polymerase to move along the template DNA strand and bind the exposed bases to complementary nucleotides that are present in the cell. This process is known as transcription and results in the production of a stand of RNA, which carries a complementary sequence of bases to the template gene on the DNA.
Multi-stage structure-based virtual screening approach towards identification of potential SARS-CoV-2 NSP13 helicase inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Mahmoud A. El Hassab, Wagdy M. Eldehna, Sara T. Al-Rashood, Amal Alharbi, Razan O. Eskandrani, Hamad M. Alkahtani, Eslam B. Elkaeed, Sahar M. Abou-Seri
Molecular dynamics (MD) simulation has been an inevitable technique in studies involving in silico drug discovery. MD provides many important parameters, data, and figures necessary in various computational and molecular modelling studies. One of the most common applications of the MD is the precise determination of the binding strength between a ligand and its target. Other applications are well reported such as studying macromolecules’ nature and characterising the effect of certain mutations on the resistance profile of many drugs27. Therefore, it was logistic to take the advantage of the MD to further endorse our protocol of virtual screening approach. Three MD simulation experiments were conducted on the free helicase, co-crystallised-helicase and FWM-1-helicase. Interestingly, the calculated RMSD for the free helicase reached more than 5 Å, while the RMSD of the co-crystalised ligand and FWM-1-helicase complexes reached 2.95 and 1.6 Å respectively at their maximum deviations Figure 8. The ability of FWM-1 to produce such a lower RMSD value is a powerful indicator of its ability to restrict the dynamic flexible nature of the helicase through the formation of a stable complex.
Emergence of varicella-zoster virus resistance to acyclovir: epidemiology, prevention, and treatment
Published in Expert Review of Anti-infective Therapy, 2021
Kimiyasu Shiraki, Masaya Takemoto, Tohru Daikoku
Double-stranded DNA needs to be separated into two single strands (replication fork) before DNA synthesis, and complementary strands are synthesized from each DNA strand to produce two new double-stranded DNA molecules during DNA replication (Figure 3). The HP complex is responsible for unwinding viral DNA at the replication fork, separating double-stranded DNA into two single strands, and synthesizing RNA primers (Okazaki fragments) in the lagging strand for DNA synthesis. DNApol initiates complementary DNA synthesis in the two separated DNA strands. The HP complex consists of three proteins: VZVORF55 (helicase), VZVORF6 (primase), and VZVORF52 (cofactor). The helicase unwinds the duplex DNA ahead of the fork and separates the double strand into two single strands. The primase lays down RNA primers that extend the two-subunit DNApol. The HP complex possesses multienzymatic activities, including DNA-dependent ATPase, helicase, and primase activities, all of which are required for the HP complex to function in viral DNA replication.
Coronavirus helicases: attractive and unique targets of antiviral drug-development and therapeutic patents
Published in Expert Opinion on Therapeutic Patents, 2021
Austin N. Spratt, Fabio Gallazzi, Thomas P. Quinn, Christian L. Lorson, Anders Sönnerborg, Kamal Singh
Helicases are ubiquitous nucleic acid unwinding enzymes. These biological motors couple the chemical energy of nucleotide triphosphate hydrolysis (NTPase) to mechanical energy that translocates through nucleic acids, unwinding the helical structure as it progresses, thus the term ‘helicase.’ Efficient genome replication, recombination and repair require single stranded DNA (ssDNA) or single stranded RNA (ssRNA) as a template that is largely devoid of secondary structures [1]. Helicases in situ generate ssDNA or ssRNA, and due to this crucial role during genome replication, repair and recombination, defects in helicase function can lead to many genetic disorders. Notable examples of helicase-associated disorders include Bloom’s syndrome, Werner’s syndrome, and X-chromosome-linked α-thalassemia [2–9].