The escalating prevalence of HIV-1 drug-resistant variants and the toxicity limitations of conventional antiretroviral therapies necessitate therapeutic strategies with novel mechanisms of action. This study focuses on HIV-1 capsid (CA), an essential replication-related viral protein. We developed CA-targeted proteolysis-targeting chimera (PROTAC) degraders by conjugating PF74-derived CA ligand IIA-4 with VHL E3 ligase ligand. Among these, VHL-3 exhibited potent anti-HIV-1 activity in MT-4 cells (EC50 = 3.0 ± 1.5 nM), a 300-fold improvement over PF74. Mechanistic studies confirmed VHL-3 dose- and time-dependently reduced CA levels in HEK293T cells (early stage, DC50 = 812 nM; late stage, DC50 = 252 nM) via a proteasome-driven pathway. Notably, it effectively degraded clinically relevant CA-resistant mutants (N74D, K70R). This work pioneers the development of CA-targeted degraders, providing a framework for next-generation anti-HIV therapies with high potency and resistance barriers.
Mei Wang, Zeyu Peng, Yang Zhou et al.· Journal of Medicinal Chemist...· 0 citations
Privileged drug structures refer to substructures that impart drug-like properties, including high target affinity, favorable pharmacokinetic profiles, and structural modifiability. In cross-species drug repositioning, targets should be prioritized based on homologous proteins that exhibit high structural and functional conservation across members of the same virus family. Subsequently, validated, safe, and druggable privileged structures must be identified. Thereafter, computational chemistry and structural biology approaches are systematically employed to evaluate the structure's potential binding affinity and mode of interaction with the newly identified disease-relevant target. In this phase, three core medicinal chemistry strategies, including side-chain replacement, conformational constraint, and scaffold hopping, are applied to optimize the lead compound. We validate this strategy through representative case studies and summarize key practical challenges: off-target toxicity and difficulties in modifying privileged scaffolds. Leveraging their advantages while innovating repositioning methods can improve drug development efficiency, quality, and responsiveness to unmet clinical needs.
Shaoqing Du, Kai Tang, Jinheng Li et al.· Journal of Medicinal Chemist...· 0 citations