A Glance into MTHFR Deficiency at a Molecular Level.

Area of Science:

• Biochemistry
• Structural Biology
• Computational Biology

Background:

• Methylenetetrahydrofolate reductase (MTHFR) deficiency is linked to protein structure variations, but the precise genotype-phenotype correlation requires further investigation.
• Understanding the impact of missense variations on MTHFR protein structure is crucial for diagnosing and managing associated phenotypes.

Purpose of the Study:

• To computationally analyze the structural and thermodynamic impact of 72 known disease-associated missense variations in the MTHFR protein.
• To identify specific variations affecting protein stability, protein-protein interactions, and domain architecture within MTHFR.

Main Methods:

• Utilized state-of-the-art computational tools to model the wild-type MTHFR protein structure, including its catalytic and regulatory domains.
• Calculated the thermodynamic change (ΔΔG) for 72 missense variations using a consensus method to assess protein destabilization.
• Analyzed the location and impact of variations on protein-protein interaction sites and mapped variations onto the protein architecture using Hidden Markov Models.

Main Results:

• 61% of disease-related MTHFR variations were found to destabilize the protein structure, affecting both catalytic and regulatory domains and correlating with known biochemical deficiencies.
• Identified that most protein-protein interaction sites involve residues in the regulatory domain; only three disease-related, destabilizing variations were located at the homodimer interface.
• Disease-associated variations and their physicochemical types exhibit unique patterns within the MTHFR protein architecture, distinguishing MTHFR deficiency.

Conclusions:

• Missense variations significantly impact MTHFR protein stability and function, with a majority leading to destabilization.
• The study highlights the importance of the regulatory domain in MTHFR protein-protein interactions and identifies specific critical variations at the dimer interface.
• Computational analysis of MTHFR variations provides unique insights into the protein architecture and disease mechanisms, aiding in understanding MTHFR deficiency.