title: A comparison of methods for the isolation and fractionation of reticulocyte ribosomes.
abstract: 1. Polysomes, ribosomes and pH5 enzymes were isolated from rabbit reticulocytes by acidifying the post-mitochondrial supernatant to pH6.0 to precipitate all ribonucleoprotein particles and about half the pH5 enzymes; the precipitate was redissolved in buffer, pH7.6, and fractionated by zone centrifuging. 2. The isolation of polysome-rich and ribosome-rich fractions from the post-mitochondrial supernatant was also examined. 3. Studies of the stability of polysomes revealed that dissociation into sub-units occurred when both bound and free Mg(2+) was chelated by EDTA or when the pH was increased above pH8.8.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002623:Chemistry Techniques, Analytical; D004492:Edetic Acid; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008274:Magnesium; D012333:RNA, Messenger; D011817:Rabbits; D012156:Reticulocytes; D012270:Ribosomes; D014461:Ultracentrifugation
chemical_list: D012333:RNA, Messenger; D004492:Edetic Acid; D008274:Magnesium