Ribosomes: analysis by cesium sulfate gradient centrifugation

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• Mammalian cytoplasmic ribosomes are essential for protein synthesis.
• Understanding ribosome structure and aggregation is crucial for cell function.
• HeLa cells are a widely used model system in biological research.

Purpose of the Study:

• To partially purify and concentrate cytoplasmic ribosomes from HeLa cells.
• To investigate the behavior of ribosomal preparations under density-gradient centrifugation.
• To characterize the nature of concentrated ribosomal material.

Main Methods:

• Partial purification of ribosomes from HeLa cell cytoplasm.
• Concentration of ribosomes using prolonged centrifugation in cesium sulfate (Cs(2)SO(4)) solution.
• Treatment of ribosomal preparations with bentonite prior to centrifugation.
• Analysis of ribosomal material by density-gradient centrifugation.

Main Results:

• Ribosomal preparations were concentrated into a zone within the Cs(2)SO(4) density gradient.
• Bentonite-treated ribosomal preparations yielded single peaks after centrifugation.
• The material recovered from these peaks consisted of aggregates of the original 74S ribosomal particles.

Conclusions:

• Cesium sulfate density-gradient centrifugation is effective for concentrating mammalian cytoplasmic ribosomes.
• Bentonite treatment can facilitate the recovery of aggregated ribosomal particles.
• The study successfully isolated aggregates of 74S ribosomes from HeLa cells.