Development of Clinically Viable Non-Muscle Myosin II Small Molecule Inhibitors with Broad Therapeutic Potential

Area of Science:

• Biochemistry
• Pharmacology
• Molecular Biology

Background:

• Non-muscle myosin II (NMII) is crucial for cellular processes but lacks selective inhibitors for therapeutic use.
• Existing inhibitors like blebbistatin non-selectively target NMII and cardiac myosin II (CMII), limiting in vivo applications due to safety concerns.

Purpose of the Study:

• To develop a novel, selective NMII inhibitor with improved safety and therapeutic potential.
• To investigate the molecular basis of selectivity for NMII over CMII.

Main Methods:

• Rational drug design and structure-based drug design were employed.
• Preclinical models of stimulant use disorder were used to assess efficacy.
• High-resolution structural analysis of MT-228 bound to myosin II was performed.

Main Results:

• MT-228 was identified as a potent and selective NMII inhibitor with 17-fold greater affinity for NMII over CMII.
• MT-228 demonstrated high brain penetration and efficacy in preclinical models of stimulant use disorder.
• Structural analysis revealed MT-228's unique binding mode conferring selectivity.

Conclusions:

• MT-228 offers a promising therapeutic candidate with a broad therapeutic window for conditions including stimulant use disorder.
• The development of MT-228 provides valuable tools for scientific research and opens avenues for future drug development targeting NMII.