Physicochemical studies of the 7 S complex of rat liver ribosomes and its components

The 7 S complex of rat liver ribosomes contains 5 S RNA and one protein (L-5). The molecular weights of these two components are 40 600 and 37 200, respectively, as estimated by analytical ultracentrifugation. Th complex stability under different solvent conditions was analyzed from the point molecular weights using a sedimentation equilibrium technique and computer stimulation. High concentrations of KCl and urea induce partial dissociation, whereas MgCl stabilizes the complex.