Light scattering studies of chick limb bud proteoglycans.

We report static and dynamic light scattering analysis on subpopulations of proteoglycan monomer isolated in milligram quantities from chick limb bud mesenchymal cell cultures by gel fractionation in dissociative solvent conditions. These experiments furnish information on radius of gyration, Rg, and hydrodynamic radius, Rh, as a function of molecular weight, Mr,w. A comparison of these quantities, rho = Rg/Rh, indicates a decrease in branch frequency with decreasing Mr,w. This is consistent with the known result that decreasing molecular weight is due to a decrease in the number of polysaccharide side chains attached to a constant protein core length. These results show that photon correlation spectroscopy can be used to monitor structural changes in macromolecules isolated from these cell cultures.