Structural Variations of Human Glucokinase Glu256Lys in MODY2 Condition Using Molecular Dynamics Study

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Glucokinase (GK) is a key glucose sensor enzyme.
• Mutations in the GK gene cause Maturity Onset Diabetes of the Young type 2 (MODY2), a form of hyperglycemia.
• Understanding GK mutations is crucial for diabetes research.

Purpose of the Study:

• To investigate the structural and energetic impact of a specific glucokinase mutation (E256K).
• To correlate molecular dynamics simulations with molecular docking to understand altered glucose binding.
• To elucidate the molecular mechanisms behind hyperglycemia in MODY2.

Main Methods:

• Molecular dynamics simulations of intact and mutated GK structures.
• Analysis of energy values and conformational variations (e.g., turns, helix-helix interactions).
• Molecular docking to assess glucose binding affinity and mode in the active site.

Main Results:

• Mutated GK exhibited altered energy values (3500 Kcal/mol vs. 5000 Kcal/mol for intact GK).
• Conformational changes included increased γ-turns, decreased β-turns, and enhanced helix-helix interactions.
• The substrate binding region volume increased, and docking scores decreased for mutated GK, indicating poorer glucose binding.

Conclusions:

• The E256K mutation significantly alters GK structure and dynamics.
• These alterations lead to impaired glucose binding and reduced catalytic activity.
• This provides a molecular explanation for the hyperglycemic state observed in MODY2.