- To establish relevant human recombinant enzyme expression systems for enzymes conjugating catechols to be used in drug metabolism studies
- To develop and prevalidate models which predict the competitive conjugation of catechols for assessing safety and for the rational design of the catechol class of drugs.
Metabolic interactions between catechol drugs and neurotransmitters and their competitive conjugation are highly relevant to new drug development, especially for the treatment of neurological and mental illnesses. Three reactions, glucuronidation, sulphation and O-methylation, compete for conjugation of catechol-derived compounds. Participants have expression systems for most cloned human isoforms of UDP-glucuronosyltransferase, sulphotransferase and catechol O-methyltransferase enzymes. Enzyme forms relevant for conjugation of catechols are identified and appropriate recombinant expression systems are selected. Enzyme assays which are suitable for determination kinetic constants for structurally diverse set of catechol substrates are developed, standardised and validated. Kinetic parameters will be determined for a set of catechols. The substrate set includes endogenous catechols, catechols drugs and other catechols selected to complement the set for optimal structural diversity. Computational chemistry and statistical modelling will be used to develop models, which predict the affinity of a given catechol to certain enzyme isoform and rate of conjugation catalysed by the respective enzyme form. The predictive ability of in vitro tests on individual enzymes and of empirical models based on their kinetic properties is evaluated by studying the conjugate profile produced by more complex systems like liver cells. Conjugates are quantitated and identified by means of combined liquid chromatography/mass spectrometry and other appropriate methods. Glucuronosyltransferases are known to be inducible. Inducibility of these enzymes by catechols is studied in human hepatocytes and in vivo in rats. Results of the project can be utilized in drug discovery and development. Metabolic fate and possible interactions of catechol compounds can be predicted before synthesis. Recombinant expression systems characterized in the project can be used for assesment of efficacy and safety of catechol drug candidates.
Funding SchemeCSC - Cost-sharing contracts
DD1 9SY Dundee
54505 Vandoeuvre Les Nancy