The Interaction of Chondroitin Sulfate with a Lipid Monolayer Observed by Using Nonlinear Vibrational Spectroscopy

We present the first vibrational sum-frequency generation spectroscopic study of chondroitin sulfate (CS) interacting with dipalmitoyl phosphatidylcholine (DPPC) at the air-liquid interface. In the presence of Ca²⁺ and CS, the DPPC headgroups reoriented, while the tail orientations remained mostly unchanged. The results further suggest a chiral secondary structure for CS.