Chondroitin sulfate interacts mainly with headgroups in phospholipid monolayers

Colloids Surf B Biointerfaces. 2016 May 1:141:595-601. doi: 10.1016/j.colsurfb.2016.02.030. Epub 2016 Feb 15.


Sulfated glycosaminoglycans are precursors of the extracellular matrix used to treat diseases related to blood clotting and degenerative joint diseases. These medical applications have been well established, but the mode of action at the molecular level, which depends on the interaction with cell membranes, is not known in detail. In this study, we investigated the interaction between chondroitin sulfate (CS) and phospholipid monolayers that mimic cell membranes. From surface pressure isotherms and polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS), CS was found to interact mainly with the polar groups of dipalmitoyl phosphatidylcholine (DPPC) and dipalmitoyl phosphatidylglycerol (DPPG), with negligible penetration into the hydrophobic tails and only small changes in monolayer elasticity for the packing corresponding to a real cell membrane. The changes in surface pressure and surface potential isotherms depended on CS concentration and on the time allowed for its adsorption onto the monolayer, which points to a dynamic adsorption-desorption process. The charge of the phospholipid was also relevant, since CS induced order into DPPC monolayers while the opposite occurred for DPPG, according to the PM-IRRAS spectra. In summary, interaction with polar groups is responsible for the CS effects on model cell membranes.

Keywords: Cell membrane model; Chondroitin sulfate; Langmuir monolayers; PM-IRRAS spectroscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1,2-Dipalmitoylphosphatidylcholine / chemistry
  • Adsorption
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism
  • Chondroitin Sulfates / chemistry*
  • Chondroitin Sulfates / metabolism
  • Kinetics
  • Membrane Lipids / chemistry*
  • Membrane Lipids / metabolism
  • Membranes, Artificial*
  • Phosphatidylglycerols / chemistry
  • Phospholipids / chemistry*
  • Phospholipids / metabolism
  • Pressure
  • Spectrophotometry, Infrared / methods
  • Surface Properties


  • Membrane Lipids
  • Membranes, Artificial
  • Phosphatidylglycerols
  • Phospholipids
  • 1,2-Dipalmitoylphosphatidylcholine
  • Chondroitin Sulfates
  • 1,2-dipalmitoylphosphatidylglycerol