Development of a Potent QS-21-Derived Adjuvant Photoaffinity Probe: Identification of Cathepsin D as the Molecular Receptor.
The saponin natural product QS-21 is a potent immunological adjuvant used in human vaccines to enhance the immune response but suffers from scarcity, instability, and dose-limiting toxicity, precluding its advancement as a stand-alone adjuvant. Further, putative cellular receptor(s) and its molecular mechanisms of acti...