E487K-Induced Disorder in Functionally Relevant Dynamics of Mitochondrial Aldehyde Dehydrogenase 2

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Background:

• Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is crucial for metabolizing toxic acetaldehyde, preventing aldehyde-associated diseases.
• A common E487K mutation significantly impairs ALDH2 activity in a dominant manner, but the mechanism remains unclear due to complex protein dynamics.

Purpose of the Study:

• To elucidate the molecular basis of ALDH2 inactivation caused by the E487K mutation using advanced computational simulations.
• To investigate the impact of the E487K mutation on ALDH2 protein dynamics, dimer interface stability, and coenzyme binding.

Main Methods:

• Microsecond-timescale molecular dynamics simulations of wild-type and E487K mutant ALDH2 complexed with coenzymes.
• Dynamic network analysis to map communication pathways within the ALDH2 protein structure.

Main Results:

• The E487K mutation increased conformational heterogeneity at dimer interfaces distant from the mutation site.
• Dynamic network analysis revealed a disrupted communication network between Glu487, dimer interfaces, and all protein subunits.
• Perturbed dynamics altered global conformational motions and destabilized essential coenzyme binding.

Conclusions:

• The E487K mutation exerts its dominant negative effect by globally reorganizing ALDH2's dynamic network, impairing coenzyme binding and catalytic function.
• Understanding these dynamic alterations provides a foundation for developing strategies to restore ALDH2 function in aldehyde-associated diseases.