POLYSOMES OF THE SEA URCHIN EMBRYO: AN IMPROVED METHOD FOR EXTRACTION OF INTEGRATED POLYSOMES |
| |
Authors: | MINORU HIRAMA YOSHITAKE MANO |
| |
Affiliation: | Department of Biochemistry Faculty of Medicine University of Tokyo, Tokyo 113, Japan |
| |
Abstract: | Suitable conditions for extracting integrated polysomes from embryos of the sea urchins, Hemicentrotus pulcherrimus and Pseudocentrotus depressus were investigated. Integrated polysomes could not be extracted under the conditions reported by other investigators. It was found, however, that use of 5 m m MgCl2, 0.30 m KCl, 0.5 m m EDTA and 2 m m cycloheximide was effective for maintaining the integrity of polysomes. At higher concentrations of Mg2+, and even at higher concentrations of K+, monosomes and polysomes aggregated to form polysome-like particles which had sedimentation patterns with a small amount of nascent peptide. Thus, a medium consisting of 0.05 m Tris-HCl buffer, pH 7.5, 0.30 m KCl. 5 m m MgCl2, 0.5 m m EDTA-2K, 2 m m cycloheximide, 5 m m mercaptoethanol and 0.5% (v/v) Nonidet P-40 is concluded to be the most suitable for extraction of sea urchin polysomes. Under the conditions used EDTA did not suppress polysome degradation completely and their degradation was linear with time. |
| |
Keywords: | |
|
|