Simulations of Pathogenic E1α Variants: Allostery and Impact on Pyruvate Dehydrogenase Complex-E1 Structure and...

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Pyruvate dehydrogenase complex (PDC) deficiency causes severe lactic acidosis with few treatments.
• PDC-E1, crucial for PDC function, has active sites affected by mutations, primarily in the PDHA1 gene.
• Disease-causing missense mutations (DMMs) often occur in inaccessible or interface regions of E1α.

Purpose of the Study:

• To investigate the structural and dynamic impact of E1α DMMs on human PDC-E1.
• To explore the communication network within PDC-E1 and how DMMs disrupt it.
• To identify potential therapeutic strategies for PDC deficiency.

Main Methods:

• Molecular dynamics simulations of wild-type (WT) and mutant PDC-E1 variants (R349, W185).
• Analysis of changes in E1 structure, dynamics, and phosphorylation Loop A.
• Centrality analysis to map and assess the PDC-E1 communication network.

Main Results:

• DMMs at R349 and W185 altered PDC-E1 structure and dynamics, even affecting distant phosphorylation Loop A.
• Disease-causing missense mutations disrupted the enzyme's internal communication network.
• Evidence of allosteric effects within the PDC-E1 structure was observed.

Conclusions:

• PDC-E1 exhibits allosteric regulation, where mutations can impact function through altered communication pathways.
• Understanding these allosteric mechanisms is key for developing targeted small-molecule therapies for PDC deficiency.
• Specific mutations, like those at R349, represent promising targets for novel therapeutic interventions.