Synthesis & Pharmacokinetic Evaluation of Cyclotriazadisulfonamide (CADA) Analogs to Target Signal Peptides

Abstract

The small molecule cyclotriazadisulfonamide (CADA) was found to down-modulate the expression of the human cluster of differentiation 4 (hCD4) glycoprotein and sortilin through a specific interaction with respective signal peptide (SP), a short chain of amino acids that initiates a highly conserved biochemical process called cotranslational translocation. The SP is an unprecedented target in modulating protein expression. Since each protein expressed through cotranslational translocation has a unique SP, small molecules may potentially be designed to target individual SPs and modulate protein expression with high specificity. The goals of this research were to synthesize CADA analogs to study the interactions between CADA and SPs, synthesize CADA analogs with enhanced drug-like properties, and establish a pharmacokinetic profile of various biologically active CADA analogs. Several CADA analogs were synthesized and investigated for their utility in photoaffinity labeling (PAL) experiments. The aryl azide CADA analog RA018 was synthesized and evaluated in PAL experiments but ultimately did not yield any labeled SP. Additionally, the synthesis of several CADA analogs with diazirines moieties was pursued and ultimately found to be unsuccessful. A series of PEGylated and mPEGylated CADA analogs were synthesized and evaluated for their biological activity and pharmacokinetic properties. These analogs exhibited better or similar potency to CADA. Finally, the pharmacokinetics of PEGylated and mPEGylated CADA analogs were analyzed alongside numerous CADA analogs that exhibit favorable biological activity and/or structural features associated with enhanced drug-like properties.