Micronutrients
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
Adenosine Triphosphate is an example of an essential non-vitamin coenzyme. In fact, Adenosine Triphosphate or Adenosine-5´-Triphosphate (ATP) is a nucleoside triphosphate composed of three compounds: a nitrogenous heterocyclic base (adenine), the sugar β-D-ribose, and three phosphate groups (92–93, 97–98). ATP is considered the single most important molecule in the cell and is often referred to as a molecule of intracellular energy transfer and as a universal coenzyme (type co-substrate) for a large number of enzymes, especially kinases (92, 98). In general, ATP carries both phosphate and energy to different places within a cell for the release of energy in situ by losing one or two of its phosphate groups, becoming adenosine diphosphate (ADP) or adenosine monophosphate (AMP), respectively. Much of the chemical energy used by cells is stored in the two phosphor-anhydride bonds of ATP which are high in energy (92, 97–98).
Pharmacological Modification of a Cerebroplegia Solution
Richard A. Jonas, Jane W. Newburger, Joseph J. Volpe, John W. Kirklin in Brain Injury and Pediatric Cardiac Surgery, 2019
Magnetic Resonance Spectroscopy. 31P magnetic resonance spectra were acquired in the Fourier transform mode on a custom-built spectrometer using the Oxford horizontal-bore 4.7 Tesla magnet and surface coil. The field homogeneity was optimized with the brain water signal. Spectra were acquired using a 90-degree excitation pulse of 60 microseconds. Each spectrum was the average of 128 acquisitions (nine minutes). Peak areas of inorganic phosphate (Pi), creatine phosphate (PCr), and beta nucleoside triphosphate were determined by Lorentzian curve fitting and peak integration (NMRI Software, New Methods Research, East Syracuse, NY). Changes in ATP concentration were assessed from the beta nucleoside triphosphate peak area. The inorganic phosphate, creatine phosphate, and ATP data are reported as percentage of the baseline data obtained during the last nine minutes of the initial full-flow normothermic bypass period. The intracellular pH in the brain (pHi) was calculated from the chemical shift of the inorganic phosphate peak relative to the creatine phosphate peak.
Replicase
Paul Pumpens in Single-Stranded RNA Phages, 2020
The presence of an RNA-dependent RNA polymerase in the lysates of the phage f2-infected E. coli cells was observed for the first time by Zinder's team (August et al. 1963). It was highly important that the pioneers of the replicase search introduced the classical replicase assay that contained (i) ribonucleoside triphosphates as substrates, (ii) phosphoenol pyruvate and phosphoenol pyruvate kinase as a nucleoside triphosphate generating system and a high concentration of potassium phosphate buffer to inhibit polynucleotide phosphorylase activity, and (iii) deoxyribonuclease to inhibit the DNA dependent-RNA polymerase activity. With this assay there was virtually no incorporation of ribonucleotides into acid-insoluble material when extracts were prepared from uninfected cells. Moreover, August et al. (1963) observed for the first time the overproduction of the replicase activity by nonpolar coat protein amber mutant f2 sus11 and the absence of this activity by the polar coat protein amber mutant f2 sus3 infection in nonpermissive cells. The activity represented the existence of the template−enzyme complexes in the infected cells, but it appeared highly difficult to purify the stable template-dependent f2 enzyme (August et al. 1965; Shapiro and August 1965a,b), as it was managed later by the group III and IV phages.
Effect of adenosine triphosphate on amiodarone-induced optic neuropathy in rats: biochemical and histopathological evaluation
Published in Cutaneous and Ocular Toxicology, 2023
Kemal Bayrakçeken, Rukiye Kilic Ucgul, Taha Coban, Gulce Yazıcı, Halis Suleyman
Although the pathogenesis of amiodarone-related toxic effects has not been fully elucidated, Betiu et al. suggested that amiodarone induced adenosine triphosphate (ATP) depletion in cells [10]. ATP is a nucleoside triphosphate consisting of adenine, ribose, and three phosphate groups [11]. In the literature, it has been reported that ATP is involved in the synthesis of antioxidants scavenging and clearing ROS [12]. Moreover, it is known that ATP is an energy source for the synthesis of low-molecular-weight antioxidants [13]. Given these outcomes, amiodarone-induced optic neuropathy may be secondary to increased ROS production and ATP deficiency. However, to the best of our knowledge, the literature contains no study investigating the effect of ATP on amiodarone-induced optic neuropathy. Therefore, the current study aims to evaluate the effect of ATP on possible optic nerve damage caused by amiodarone in rats, and to examine the optic nerve tissue biochemically and histopathologically.
Hepatic manifestations of COVID-19 and effect of remdesivir on liver function in patients with COVID-19 illness
Published in Baylor University Medical Center Proceedings, 2021
Abdul Aleem, Guruprasad Mahadevaiah, Nasir Shariff, Jiten P. Kothadia
Remdesivir (GS-5734) is a pro-drug of a monophosphate nucleoside analog (GS-441524) and manifests as a viral RNA-dependent RNA polymerase (RdRp) inhibitor that targets the viral genome replication process. Hypothetically, nucleoside analogs are unable to permeate the cell wall easily. Upon gaining entry into the host cell, the adenosine nucleotide pro-drug is metabolized to a nucleoside monophosphate intermediate by carboxyesterase 1 and/or cathepsin A. The nucleoside monophosphate undergoes subsequent phosphorylation to produce nucleoside triphosphate, which resembles adenosine triphosphate and can be used by the RdRp enzymes or complexes for genome replication. After remdesivir is metabolized into the pharmacologic active analog adenosine triphosphate (GS-443902) by the host cells, it vies with adenosine triphosphate for integration by the RdRp complex into the nascent RNA strand and, upon subsequent integration of a few more nucleotides, results in termination of viral RNA synthesis.17–21
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].
Related Knowledge Centers
- Deoxyribose
- DNA
- DNA Replication
- Nucleobase
- Nucleoside
- Nucleotide
- Phosphate
- Rna
- Transcription
- Nucleoside Analogue