RESUMO
Natural product discovery arises through a unique interplay between chromatographic purification and biological assays. Currently, most techniques used for natural product purification deliver leads without a defined biological action. We now describe a technique, referred to herein as functional chromatography, that deploys biological affinity as the matrix for compound isolation.
Assuntos
Produtos Biológicos/isolamento & purificação , Produtos Biológicos/química , CromatografiaRESUMO
Access to lead compounds with defined molecular targets continues to be a barrier to the translation of natural product resources. As a solution, we developed a system that uses discrete, recombinant proteins as the vehicles for natural product isolation. Here, we describe the use of this functional chromatographic method to identify natural products that bind to the AAA+ chaperone, p97, a promising cancer target. Application of this method to a panel of fungal and plant extracts identified rheoemodin, 1-hydroxydehydroherbarin, and phomapyrrolidone A as distinct p97 modulators. Excitingly, each of these molecules displayed a unique mechanism of p97 modulation. This discovery provides strong support for the application of functional chromatography to the discovery of protein modulators that would likely escape traditional high-throughput or phenotypic screening platforms.
Assuntos
Adenosina Trifosfatases/metabolismo , Produtos Biológicos/farmacologia , Proteínas Nucleares/metabolismo , Alcaloides/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Cromatografia/métodos , Descoberta de Drogas/métodos , Fungos/química , Humanos , Naftoquinonas/química , Naftoquinonas/isolamento & purificação , Naftoquinonas/farmacologia , Plantas/químicaRESUMO
Understanding the mode of action (MOA) of many natural products can be puzzling with mechanistic clues that seem to lack a common thread. One such puzzle lies in the evaluation of the antitumor properties of the natural product withaferin A (WFA). A variety of seemingly unrelated pathways have been identified to explain its activity, suggesting a lack of selectivity. We now show that WFA acts as an inhibitor of the chaperone, p97, both in vitro and in cell models in addition to inhibiting the proteasome in vitro. Through medicinal chemistry, we have refined the activity of WFA toward p97 and away from the proteasome. Subsequent studies indicated that these WFA analogs retained p97 activity and cytostatic activity in cell models, suggesting that the modes of action reported for WFA could be connected by proteostasis modulation. Through this endeavor, we highlight how the parallel integration of medicinal chemistry with chemical biology offers a potent solution to one of natures' intriguing molecular puzzles.