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. 1974 Jan;71(1):68–72. doi: 10.1073/pnas.71.1.68

Use of Purified Polysomes from Rabbit Reticulocytes in a Specific Test for Initiation Factors

Nicolette H Lubsen 1, Bernard D Davis 1
PMCID: PMC387933  PMID: 4521057

Abstract

Initiation factors, extracted from ribosomal particles by high salt, are usually tested for with the extracted ribosomes. However, it is theoretically possible that such tests may respond not only to factors (i.e., proteins that join and leave a ribosome during its cycle), but also to true ribosomal proteins that may have been extracted. We have eliminated this circularity by tests with purified polysomes, which have not been extracted with high salt; the polysomes are deficient in initiation factors because they have been largely separated from the native subunits. Tests with both systems, applied to extracts of different classes of particles, suggest that high salt does extract both initiation factors and essential ribosomal proteins. Extracts of native subunits contain both, and stimulate both systems; while, in the presence of these extracts, the extracts of polysomes further stimulate only the extracted ribosomes.

Keywords: protein synthesis, native subunits

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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