[55] Isodensity equilibrium centrifugation of ribosomal particles; the calculation of the protein content of ribosomes and other ribonucleo-proteins from buoyant density measurements by Mary G. Hamilton.
Isodensity or isopycnic equilibrium centrifugation is a sensitive way to detect density differences among macromolecules. This chapter demonstrates that for ribosomes and their subunits the anhydrous protein-RNA line should be used estimate protein content from buoyant in CsCI. The of macromolecule represents balance several factors, chief which chemical composition. While nucleic acids accountable terms hydration lowers density, specific binding salts increases it, situation proteins complicated. In case ribosomes, presumable, ion effectively fortuitously cancel one another CsCI, whereas Cs 2 SO 4 effects may predominate. structural arrangement RNA must affect behavior. When, are both exposed surface, component seems overshadow contribution protein.