Dynamic Water Hydrogen-Bond Networks at the Interface of a Lipid Membrane Containing Palmitoyl-Oleoyl Phosphatidylglycerol

• Published in: The Journal of membrane biology Vol. 251; no. 3; pp. 461 - 473
• Main Authors: Karathanou, Konstantina, Bondar, Ana-Nicoleta
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2018; Springer Nature B.V
• Subjects: applications; Binding; Biochemistry; Biomedical and Life Sciences; Clusters; experiments; Human Physiology; Hydrogen; Hydrogen Bonding; Hydrogen bonds; Interfaces; Lecithin; Life Sciences; Lipid Bilayers - chemistry; Lipid Membranes and Reactions at Lipid Interfaces: Theory; Lipids; Membrane Lipids - chemistry; Membranes; Molecular Dynamics Simulation; Phosphatidylcholine; Phosphatidylglycerol; Phosphatidylglycerols - chemistry; Proteins; Water - chemistry; Anionic lipid membranes; Dynamic hydrogen-bond networks; Water–lipid interactions
• ISSN: 0022-2631; 1432-1424; 1432-1424
• DOI: 10.1007/s00232-018-0023-1

Lipid membrane interfaces are complex environments that host essential cellular processes such as binding of proteins or drug molecules. A key open question is how water molecules at the interface of membranes with anionic lipids participate in protein binding. To address this question, we studied the dynamics of water hydrogen bonding at the interface of membranes composed of phosphatidylcholine and phosphatidylglycerol, and implemented an algorithm to identify hydrogen-bonded networks at the interface of a lipid membrane, and to characterize their dynamics and linear connections. We find that the membrane interface is characterized by a rich network of hydrogen-bonded water chains that bridge lipid headgroups, some of which form transient lipid clusters. Water-mediated bridges between with lipid phosphate groups are dynamic, with residence lifetimes on the order of picoseconds. These clusters of water/lipid headgroup hydrogen bonds could provide a platform for the binding of proteins or of drug molecules with cationic groups.