Two Dimensional and Three Dimensional Interactions between Bovine Serum Albumin and Chondroitin Sulfate

Abstract

The interaction between glycosaminoglycan and protein in solution and at interface are important for the biofunctions of tissues. We previously reported that the binding behavior between sodium hyaluronate NaHA and bovine serum albumin BSA both in solution and at interface. Here, two- and three-dimensional interactions between sodium chondroitin sulfate Na 2 ChS and BSA were studied by an electrophoretic light scattering ELS and a quartz crystal microbalance QCM method. Na 2 ChS molecules bound to BSA molecules by an electrostatic force and form soluble complex in solution. Their molar ratio γ = n BSA / n Chs of the saturated complex was about 6-7. However, the value of γ was about 1 at interface when the binding between Na 2 ChS and BSA became saturated. Na 2 ChS molecules could adsorb onto a BSA monolayer by a hydrophobic force in a Langmuir type. Its adsorption layer was a double-layer structure from the results. The results of Na 2 ChS-BSA complex in solution and at interface were discussed by comparing with the binding behavior between sodium hyaluronate NaHA and BSA to elucidate the effects of the sulfate group and charee density of Na 2 ChS.