Mass spectrometric characterization of circulating covalent protein adducts derived from a drug acyl glucuronide metabolite: multiple albumin adductions in diclofenac patients
| Autor: | Guruprasad P. Aithal, Stuart Norman Lile Bennett, Ira Pande, Dominic P. Williams, Caroline Earnshaw, Rosalind E. Jenkins, Andrew V. Stachulski, Xiaoli Meng, B. Kevin Park, J. Gerry Kenna, Thomas G. Hammond, James L. Maggs, Sophie L. Regan, Anahi Santoyo Castelazo |
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| Rok vydání: | 2014 |
| Předmět: |
Adult
Male Diclofenac Stereochemistry Metabolite Serum albumin Plasma protein binding Toxicology Mass Spectrometry chemistry.chemical_compound Glucuronides In vivo Glycation medicine Humans Carboxylate Serum Albumin Aged Pharmacology biology Anti-Inflammatory Agents Non-Steroidal Albumin Middle Aged Human serum albumin chemistry Biochemistry biology.protein Molecular Medicine Female medicine.drug Protein Binding |
| Zdroj: | The Journal of pharmacology and experimental therapeutics. 350(2) |
| ISSN: | 1521-0103 |
| Popis: | Covalent protein modifications by electrophilic acyl glucuronide (AG) metabolites are hypothetical causes of hypersensitivity reactions associated with certain carboxylate drugs. The complex rearrangements and reactivities of drug AG have been defined in great detail, and protein adducts of carboxylate drugs, such as diclofenac, have been found in liver and plasma of experimental animals and humans. However, in the absence of definitive molecular characterization, and specifically, identification of signature glycation conjugates retaining the glucuronyl and carboxyl residues, it cannot be assumed any of these adducts is derived uniquely or even fractionally from AG metabolites. We have therefore undertaken targeted mass spectrometric analyses of human serum albumin (HSA) isolated from diclofenac patients to characterize drug-: derived structures and, thereby, for the first time, have deconstructed conclusively the pathways of adduct formation from a drug AG and its isomeric rearrangement products in vivo. These analyses were informed by a thorough understanding of the reactions of HSA with diclofenac AG in vitro. HSA from six patients without drug-: related hypersensitivities had either a single drug-: derived adduct or one of five combinations of 2-8 adducts from among seven diclofenac N-acylations and three AG glycations on seven of the protein's 59 lysines. Only acylations were found in every patient. We present evidence that HSA modifications by diclofenac in vivo are complicated and variable, that at least a fraction of these modifications are derived from the drug's AG metabolite, and that albumin adduction is not inevitably a causation of hypersensitivity to carboxylate drugs or a coincidental association. |
| Databáze: | OpenAIRE |
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