title: On the dissociation and association of Escherichia coli ribosomes.
abstract: The dissociation and association behaviour of 70-S ribosomes of Escherichia coli has been studied. It has been shown that the dissociation-association reaction can be both a real dynamic equilibrium and a non-equilibrium reaction, dependent upon the ionic conditions of the solvent. At relatively high ionic strength (I = 0.15 M or more) the dissociation-association reaction is an equilibrium reaction, whereas at lower ionic strength (I = 0.1 M or less) there is no dynamic equilibrium between 70-S ribosomes and its subunits. In the latter case a hysteresis in the dissociation-association reaction is observed. Whether there is a dynamic equilibrium or not can be demonstrated by a single centrifugation experiment, using the analytical ultracentrifuge.
mesh_terms: D004926:Escherichia coli / Q000648:ultrastructure*; D046911:Macromolecular Substances; D008274:Magnesium; D009994:Osmolar Concentration; D012270:Ribosomes; D014461:Ultracentrifugation
chemical_list: D046911:Macromolecular Substances; D008274:Magnesium