Interaction of polyethylene glycol (PEG) with the membrane-binding domains following spinal cord injury (SCI): introduction of a mechanism for SCI repair

Abstract

Lipid-binding domains regulate positioning of the membrane proteins via specific interactions with phospholipid’s head groups. Spinal cord injury (SCI) diminishes the integrity of neural fiber membranes at nanoscopic level. In cases that the ruptured zone size is beyond the natural resealing ability, there is a need for reinforcing factors such as polymers (e.g. Polyethylene glycol) to patch the dismantled axoplasm. Certain conserved sequential and structural patterns of interacting residues specifically bind to PEGs. It is also found that PEG600, PEG400 and PEG200 share the strongest interaction with the lipid-binding domains even more successful than phospholipid head groups. The alpha helix structure composed of hydrophobic, neutral and acidic residues prepares an opportunity for PEG400 to play an amphipathic role in the interaction with injured membrane. This in-silico study introduces a mechanism for PEG restorative ability at the molecular level. It is believed that PEG400 interrelates the injured membrane to their underneath axoplasm while retaining the integrity of ruptured membrane via interaction with ENTH domains of membrane proteins. This privilege of PEG400 in treating injured membrane must be considered in designing of polymeric biomaterials that are introduced for SCI repair.

• Membrane healing
• polymeric biomaterials
• spinal cord repair

Acknowledgements

The authors wish to thank Dr. Hamid Hadi Alijanvand for technical support. We also appreciate the kindly contribution of Dr. Hamid Mobasheri, Dr. Sogolie Kouhzaei and Dr. Mohammad-Hossein Karimi-Jafari for their useful comments.

Declaration of interest

The authors declare no conflicts of interest. The authors alone are responsible for the content and writing of this paper.

Notice of Correction:

Information regarding equally contributing authors was added to the manuscript after it was published online on 30 May 2014.