Design of Y2 Receptor Selective and Proteolytically Stable PYY3-36 Analogues.

In recent years peptide YY (PYY) has attracted attention within the area of diabetes and obesity due to its involvement in food intake regulation and glucose homeostasis. It is well-known that PYY1-36 is rapidly cleaved by dipeptidyl peptidase-4 to the more Y2 receptor selective analogue PYY3-36, which is further cleaved to the inactive analogue PYY3-34. In order to improve the selectivity and proteolytic stability of the C-terminus, we synthesized several analogues incorporating N-methyl amino acids or ß-homo amino acids and other non-natural amino acids. These were tested against all four NPY receptors, and highly potent and Y2 receptor selective analogues were identified by combining a tryptophan residue in position 30 with either N-methyl or ß-homo arginine in position 35. We also identified an analogue with a MeGln34 substitution that surprisingly displayed high affinity toward all four receptors. In addition, these analogues displayed improved stability toward C-terminal proteolysis compared to native PYY3-36.

Metabolic activation of carboxylic acids.

BACKGROUND: Carboxylic acids constitute a large and heterogeneous class of both endogenous and xenobiotic compounds. A number of carboxylic acid drugs have been associated with adverse reactions, linked to the metabolic activation of the carboxylic acid moiety of the compounds, i.e., formation of acyl-glucuronides and acyl-CoA thioesters. OBJECTIVE: The objective is to give an overview of the current knowledge on metabolic activation of carboxylic acids and how such metabolites may play a role in adverse reactions and toxicity. METHODS: Literature concerning the formation and disposition of acyl glucuronides and acyl-CoA thioesters was searched. Also included were papers on the chemical reactivity of acyl glutathione-thioesters, and literature concerning possible links between metabolic activation of carboxylic acids and reported cellular and clinical effects. RESULTS/CONCLUSION: This review demonstrates that metabolites of carboxylic acid drugs must be considered chemically reactive, and that the current knowledge about metabolic activation of this compound class can be a good starting-point for further studies on the consequences of chemically reactive metabolites.