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Macronutrients
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
The name of an enzyme has two parts. The first part is the name of the substrate, and the second part is terminated with a suffix -ase (54). For example, protease is an enzyme of the substrate protein. For the international nomenclature, the name of an enzyme is preceded by the two letters EC (Enzyme Commission) followed by four numbers. For example, E.C.2.7.1.1. The first number denotes one of the six main classes: oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. The second number denotes the subclass and the third number denotes the sub-subclass. The last number denotes the serial number of the enzyme in its sub-subclass (53–54). Enzymes are classified based on the reactions they catalyze into six classes cited above. Oxidoreductases such as glutathione reductase, lactate dehydrogenase, and glucose-6-phosphate dehydrogenase are the enzymes that catalyze oxidation-reduction reactions of their substrates. Transferases transfer a functional group between two substrates such as a methyl or phosphate group. Hydrolases catalyze the hydrolysis reactions of carbohydrates, proteins, and esters. Lyases cleave various chemical bonds by other means than hydrolysis and oxidation for the formation of double bonds. Isomerases are involved in isomerization of substrate where interconversion of cis-trans isomers is implicated. Ligases such as alanyl-t-RNA synthetase, glutamine synthetase, and DNA ligases join together two substrates with associated hydrolysis of a nucleoside triphosphate (53–54).
Chemopreventive Agents
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
On the other hand, Phase II enzymic transformations, also known as conjugation reactions, facilitate the attachment of small polar molecules (e.g., sugars) to xenobiotics or intermediate Phase I metabolites to produce less biologically active and/or or more water-soluble molecules that can be eliminated more easily. A wide variety of enzymes participate in this process, including glutathione-S-transferases (GSTs), sulfotransferases, UDP-glucuronosyltransferases (UGT), N-acetyltransferases (NATs), and methyltransferases (MTs). Some chemopreventive agents may work by enhancing the Phase II metabolism of pro-carcinogens or carcinogens thus facilitating their elimination from the body.
Nutrition Therapy of Inborn Errors of Metabolism
Published in Fima Lifshitz, Childhood Nutrition, 2020
Kimberlee Michals-Matalon, Reuben Matalon
Galactosemia is caused by enzyme defects affecting galactose utilization.21 The disease most commonly associated with galactosemia is deficiency of the enzyme galactose-1 -phosphate uridyl transferase. Many states screen for this condition in the newborn period. Patients with galactosemia present with vomiting after ingestion of galactose-containing formula. If galactose ingestion continues, the patient fails to thrive, has deranged liver functions which progress to jaundice, hepatomegaly, and later hemolysis and ascites, with deaths often occurring due to E-coli sepsis. If the patient survives, there can be mental retardation and cataracts.
Anti-phospholipase A2 receptor antibodies directly induced podocyte damage in vitro
Published in Renal Failure, 2022
Yanfen Li, Juntao Yu, Miao Wang, Zhao Cui, Ming-hui Zhao
Functional classification on gene ontology molecular function (GO-MF) of these 120 specific proteins was presented in Figures 3(C–G). There were 163 genes that participated in the expression of 120 specific proteins. 133/163 genes hit the GO-MF database and were involved in 4660 categories in GO-MF, while 37/4660 categories presented significant fold enrichment (p< 0.05). The top 10 categories with the lowest p-value were shown in Figure 3(C). There were 24/37 categories related to binding. Considering the number of gene hits, the categories of catalytic activity and binding constituted more than 80% of GO-MF functional database hits (catalytic activity: 57/133, 42.9%; binding: 50/133, 37.6%) (Figure 4(D)). The categories of hydrolase activity (26/66, 39.4%) and transferase activity (15/66, 22.7%) constituted more than 60% of the functional hits in catalytic activity (Figure 4(E)). The categories of protein binding (28/56, 50.0%) and nucleic acid binding (20/56, 35.7%) constituted more than 80% of the functional hits in binding (Figure 4(F)). The hierarchical relationship of all 133 GO-MF-relevant genes was illustrated in the treemap (Figure 4(G)). The scales of rectangles were defined by the -log10 (p-value) of each entry. The root entries of protein binding, actin filament binding, and microtubule motor activity were the major components in GO-MF categories, which suggested that there might be disorder in the function of cytoskeleton structure, cell junction, migration, and signal transduction, after the treatment of anti-PLA2R antibodies on podocytes.
KRAS G12C inhibition and innate immune targeting
Published in Expert Opinion on Therapeutic Targets, 2021
Tetsuo Tani, Shunsuke Kitajima, Ella B. Conway, Erik H. Knelson, David A. Barbie
Although farnesyltransferase inhibitors advanced to phase III trials, they failed to meet primary endpoints [23]. Preclinical work sheds light on potential mechanisms of resistance, which may have been obscured by over-reliance on HRAS mutant models in the development of farnesyltransferase inhibitors. Farnesyltransferase is critical for RAS anchoring to the membrane in HRAS mutant tumors, but geranylgeranyl transferase type I governs the process in the absence of farnesyltransferase in KRAS and NRAS mutant tumors, identifying a potential mechanism of resistance to farnesyltransferase inhibitors [23,24]. These findings raise the possibility of future combination therapies to inhibit these post-translational modifications in KRAS and NRAS mutant tumors.
Influence of some β-lactam drugs on selected antioxidant enzyme and lipid peroxidation levels in different rat tissues
Published in Drug and Chemical Toxicology, 2020
Fikret Türkan, Zübeyir Huyut, Yıldıray Basbugan, İlhami Gülçin
In recent years, inhibition studies involving many antibiotics have been carried out extensively. These studies were conducted on various enzymes, including paraoxonase (Demir and Beydemir 2015, Turkes et al.2015), glucose-6-phosphate dehydrogenase (Ozmen et al.2005), 6-phosphogluconate dehydrogenase (Akyüz et al.2004), GR (Erat et al.2005), and glutathione-S-transferase (Türkan et al.2014). In vivo results from enzymatic-activity studies are crucial for identifying the physiological role of these enzymes. Particularly, studies on drug–enzyme or any chemical compound–enzyme interactions are important to understand toxicological mechanisms. In this study, we evaluated inhibitory effects of cefazolin, cefuroxime, and cefoperazone in vivo on GST enzymatic activity.