Identification of a Novel Core Structure of Apo-Ido1 Inhibitors Through Virtual Screening and Preliminary Hit...

Area of Science:

• Biochemistry and Molecular Biology
• Computational Chemistry
• Pharmacology

Background:

• Indoleamine 2,3-dioxygenase 1 (IDO1) is a validated therapeutic target for cancer and neurodegenerative diseases.
• Traditional IDO1 inhibitors face challenges due to limited clinical efficacy.
• Apo-IDO1 inhibitors present a novel strategy for selective and durable IDO1 inhibition.

Purpose of the Study:

• To establish a virtual screening (VS) workflow for identifying novel apo-IDO1 inhibitors.
• To discover and optimize small molecules targeting apo-IDO1.
• To provide a starting point for developing new anticancer therapeutics.

Main Methods:

• Virtual screening workflow incorporating molecular docking and binding pose metadynamics (BPMD).
• Biological evaluation of identified hit compounds for apo-IDO1 selectivity and heme binding disruption.
• Molecular dynamics simulations (random accelerated MD, self-organizing maps) for structure optimization and mechanism exploration.

Main Results:

• Identification of a hit compound, MQ-1 (IC50 = 1.29 μM), with selective apo-IDO1 targeting and heme binding disruption.
• Optimization of MQ-1 led to analogs with significantly improved inhibitory activity, such as MQ-1n (IC50 = 0.29 μM).
• The VS workflow proved effective for IDO1 and applicable to similar enzymatic targets.

Conclusions:

• The developed VS workflow is a powerful tool for discovering novel apo-IDO1 inhibitors.
• The identified novel apo-IDO1 inhibitor core structure holds potential for future anticancer drug development.
• This study validates apo-IDO1 inhibition as a viable therapeutic strategy.