Palmitoylation modifies transmembrane adaptor protein PAG for ordered lipid environment: A molecular dynamics...

Area of Science:

• Biophysics
• Molecular Biology
• Membrane Biophysics

Background:

• Palmitoylation is a key post-translational modification influencing protein function and localization.
• Transmembrane peptides play critical roles in membrane organization and cellular processes.
• Understanding peptide-membrane interactions is crucial for cell signaling and drug delivery.

Purpose of the Study:

• To investigate the effect of palmitoylation on the PAG transmembrane peptide.
• To explore peptide behavior in different lipid environments, including the challenging lipid-ordered (Lo) and lipid-disordered (Ld) boundary regions.
• To elucidate the impact of palmitoylation on membrane properties like thickness and hydration.

Main Methods:

• All-atom molecular dynamics (MD) simulations were utilized.
• Simulations were performed across diverse lipid environments, focusing on phase boundaries.
• Membrane thickness and hydration levels were analyzed in response to peptide modification.

Main Results:

• Palmitoylation reduced the peptide's impact on membrane thickness, especially in Lo and boundary regions.
• Hydrophobic palmitoyl chains did not significantly alter surrounding membrane hydration.
• The palmitoylated peptide exhibited a strong preference for the boundary membrane environment, suggesting accumulation potential.

Conclusions:

• Palmitoylation significantly modifies PAG peptide interactions with lipid membranes.
• The boundary membrane region is a favorable environment for palmitoylated peptides.
• Findings have implications for understanding cell signaling, membrane organization, and optimizing lipid-based drug delivery systems.