Investigations on the relationship between structural properties of carboxylic acids and the tendency of forming CoA conjugates
Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
Formation of reactive metabolites that are capable of binding covalently to endogenous proteins and cause cellular dysfunction is considered a key mechanism in idiosyncratic adverse drug reactions. Carboxylic acid drugs have been associated with idiosyncratic hepatotoxicity and can form xenobiotic-S-acyl-coenzyme A thioesters (CoA conjugates), a reaction catalyzed by acyl-coenzyme A synthetases (ACSs). The overall aim of this project is to evaluate if there is a relationship between structural properties of carboxylic acids and the tendency of forming potentially reactive CoA conjugates.
In vitro method using human liver microsomes supplemented with coenzyme A and ATP was applied to study formation of CoA conjugates. Metabolites were identified using reversed phase UPLC-Q-ToF MS. Conditions used for termination of the reaction and during Q-ToF MS analysis were optimized. Time- and concentration-dependent formation was studied and Km values (indicative of the enzyme-substrate affinity) were estimated fitting data to the Michaelis-Menten equation.
Eight out of 20 incubated compounds (ibufenac, ibuprofen, (S)-AZD6610, (R)-AZD6610, 3-phenylpropionoic acid, α-methylhydrocinnamic acid, 2-fluoro-3-phenylpropanoic acid and 5-phenylvaleric acid) formed CoA conjugates. Km was estimated to: 200±19 µM for ibufenac, >960 µM for ibuprofen, 92±11 µM for 3-phenylpropionic acid, 120±19 µM for α-methylhydrocinnamic acid and 740±82 µM for 5-phenylvaleric acid. Results show that increasing the substitution at the α-carbon of carboxylic acids decreases the affinity for microsomal ACSs and that there is a relationship between structural properties of carboxylic acids and the tendency of forming CoA conjugates.
Place, publisher, year, edition, pages
2016. , 56 p.
carboxylic acids, coenzyme A, conjugation, relationship
Pharmacology and Toxicology
IdentifiersURN: urn:nbn:se:uu:diva-273738OAI: oai:DiVA.org:uu-273738DiVA: diva2:896055
Subject / course
Master of Science Programme in Pharmacy
Weidolf, LarsDarnell, MalinLeandersson, Carina
Hellman, Björn, Professor