Abstract
Anomalous sedimentation patterns arise when free ribosomes from sea urchin eggs are centrifuged at high speeds. Pressure-induced dissociation of the ribosomes during sedimentation can explain the peculiar behavior; the assumption of such dissociation also yields estimates of the equilibrium constant (as a function of KCl concentration) and the change in molecular volume (500 ± 100 ml/mol) in the reaction: subunits ⇄ ribosome. Such dissociation during centrifugation may explain many experiments in which apparent reduced sedimentation coefficients for ribosomes, and increased coefficients for the subunits, have been ascribed to conformational changes.
Keywords: ultracentrifuge, sea urchin, Strongylocentrotus, ribosomal conformation
Full text
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Selected References
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