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Thesis - Open Access

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Master of Science (MS)




Early attempts to isolate polyribosomes from barley tissue by the procedure of Lin and Key were unsuccessful. When analyzed by sucrose gradient centrifugation such preparations showed a particle distribution predominately in the monomer region of the gradient similar to data of Srivastava and Arglebe . Similar difficulties were also encountered with certain animal tissues. They were resolved by the addition of higher levels of KC1 to the extraction medium than used initially by Wettstein. The beneficial effects of monovalent ions can be explained In various ways. Petermann and Pavlovec suggested that high salt levels prevented the binding of extraneous proteins, basic proteins in particular, to the ribosomal particles. Earl and Korner demonstrated that amino acid incorporation into proteins was inhibited when polyribosomes were extracted from muscle tissue under low Ionic conditions. Particles isolated in this manner were shown to have a usually high protein to nucleic acid ratio. Earl and Morgan have more recently provided verification of these earlier results. Heywood have shown that high ionic strength was necessary to prevent co-precipitation of polyribosomes with myosin, a result similar to that reported by Earl and Morgan (7) for preparations from cardiac muscle (See more in text).

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South Dakota State University