P176S Mutation Rewires Electrostatic Interactions That Alter Maspin Functionality.

Area of Science:

• Oncogenic protein function
• Molecular dynamics simulations
• Protein-protein interactions

Background:

• Maspin's tumor-inhibiting roles are context-dependent.
• Polymorphic maspin variants (e.g., maspin-S176, maspin-P176) exhibit opposing effects on tumor progression.
• Conflicting reports on maspin function may stem from its polymorphic forms.

Purpose of the Study:

• To investigate the molecular basis for the conflicting roles of maspin polymorphic forms.
• To establish a link between maspin variants and tumor progression using computational methods.
• To elucidate how maspin's structure and interactions differ between variants.

Main Methods:

• Long molecular dynamics simulations were employed.
• Analysis of dynamic stability, differential contacts, and electrostatic energetics.
• Investigation of altered polar contacts and allosteric control in maspin variants.

Main Results:

• Maspin exhibits dynamic stability regardless of the amino acid at position 176.
• Polymorphic forms display differential inter-residue contacts and altered electrostatic energetics.
• Altered electrostatics in maspin variants disrupt allosteric control and change binding partner interactions.

Conclusions:

• The study elucidates how maspin's polymorphic forms lead to distinct protein-cofactor interaction landscapes.
• Altered electrostatic properties in maspin variants affect binding partner localization and preference.
• Understanding these molecular differences can guide therapeutic strategies targeting maspin in cancer.