1. The mercapturic acid (MA) pathway is a metabolic route for the processing of glutathione conjugates to MA (N-acetylcysteine conjugates). An N-acetyltransferase enzyme, NAT8, catalyzes the transfer of an acetyl group from acetyl-CoA to the cysteine amino group, producing a MA, which is excreted in the urine. We expressed human NAT8 in HEK293T cells and developed an HPLC-MS method for the quantitation of the S-aryl-substituted cysteine conjugates and their MA. 2. We measured the activity of the enzyme for acetylation of benzyl-, 4-nitrobenzyl-, and 1-menaphthylcysteine substrates. 3. NAT8 catalyzed the acetylation of all three cysteine conjugates with similar Michaelis-Menten kinetics.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1080/00498254.2016.1178410 | DOI Listing |
Turk J Chem
November 2024
Division of Organic Chemistry, Department of Chemistry, Faculty of Engineering, İstanbul University-Cerrahpaşa, İstanbul, Turkiye.
The detection of intracellular biothiols (cysteine, N-acetyl cysteine, and glutathione) with high selectivity and sensitivity is important to reveal biological functions. In this study, a 2-(2-methoxy-4-methylphenoxy)-3-chloro-5,8-dihydroxynaphthalene-1,4-dione (DDN-O) compound was newly synthesized and used as a fluorogenic probe (detector molecule) in the fluorometric method for the rapid, highly selective, and sensitive determination of biothiols. The intensity values (λ = 260 nm, λ = 620 nm) of the product were measured by adding biothiols to the reaction medium at varying concentrations and the glutathione equivalent thiol content values of each biothiol were calculated.
View Article and Find Full Text PDFCancer Chemother Pharmacol
January 2025
Department of Clinical Pharmacy, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Engineering and Technology Research Center for Pediatric Drug Development, Shandong Medicine and Health Key Laboratory of Clinical Pharmacy, Jinan, 250014, China.
Purpose: PLB1004, developed by Beijing Avistone Biotechnology Co., Ltd., is a safe, highly selective, and efficient irreversible epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) employed in treating non-small-cell-lung-cancer (NSCLC).
View Article and Find Full Text PDFNat Chem Biol
January 2025
State Key Laboratory of Membrane Biology, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology (Ministry of Education), Tsinghua University, Beijing, China.
The E2 ubiquitin (Ub)-conjugating enzyme primarily determines Ub conjugation as Ub-isopeptide (lysine), Ub-oxyester (serine/threonine) or Ub-thioester (cysteine). However, E2-specific Ub conjugation profiles within cells remain elusive. Here we developed the fusion E2-Ub-R74G profiling (FUSEP) strategy to access E2-specific Ub conjugation profiles in cells with amino acid resolution.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Henan Normal University School of Chemistry and Chemical Engineering, Chemistry, CHINA.
ADP-ribosylation is a complex post-translational modification involved in key physiological processes and associated with various health and disease states. The growing interest in ADP-ribosylation necessitates straightforward and efficient synthetic methods for the preparation of ADP-ribosylated peptides/proteins. In this study, we report a facile reaction between nicotinamide adenine dinucleotide (NAD+) and alcohols promoted by a combination of ionic liquids, yielding up to 94% with α:β ratios ranging from 88:12 to 99:1 and a switchable configuration selectivity.
View Article and Find Full Text PDFJ Med Chem
January 2025
Department of Respiratory and Critical Care Medicine, Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-Related Molecular Network, Precision Medicine Key Laboratory of Sichuan Province & Precision Medicine Center, State Key Laboratory of Respiratory Health and Multimorbidity, West China Hospital of Sichuan University, Chengdu 610041, China.
Radiolabeled peptides are vital for positron emission tomography (PET) imaging, yet the F-labeling peptides remain challenging due to harsh conditions and time-consuming premodification requirements. Herein, we developed a novel vinyltetrazine-mediated bioorthogonal approach for highly efficient F-radiolabeling of a native peptide under mild conditions. This approach enabled radiosynthesis of various tumor-targeting PET tracers, including targeting the neurofibromin receptor (), the integrin αβ (), and the platelet-derived growth factor receptor β (), with a radiochemical yield exceeding 90%.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!