ARTICLE

ELECTRON MICROSCOPE EXAMINATION OF SUBCELLULAR FRACTIONS

Maurice Wibo ¹, Alain Amar-Costesec ¹, Jacques Berthet ¹, and Henri Beaufay ¹

¹ From Laboratoire de Chimie Physiologique, Université de Louvain, Louvain, Belgium

Rat liver microsomes and microsomal subfractions isolated by density equilibration were submitted to a quantitative morphological and biochemical analysis. The total area of the endoplasmic reticulum was estimated at 7.3 m² per g of liver. The microsome fraction contained 2.8 mg of phospholipids and 6.7 mg of proteins per m² of membrane area. After correction for ribosomal and intracisternal proteins, the latter value was lowered to 4.7 mg of membrane protein per m². More than half of the microsomal vesicles carried ribosomes. After density equilibration of the microsomes, the distribution pattern of ribosomes followed closely that of RNA. The ribosome load of the microsomal vesicles increased steadily along the density gradient, indicating the existence of a continuous spectrum of microsomal entities ranging from entirely ribosome-free vesicles to vesicles heavily coated with ribosomes.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

• Rajasekaran, A., Morimoto, T, Hanzel, D., Rodriguez-Boulan, E, Kreibich, G (1993). Structural reorganization of the rough endoplasmic reticulum without size expansion accounts for dexamethasone-induced secretory activity in AR42J cells. J. Cell Sci. 105: 333-345 [Abstract]  
• Duve, C (1975). Exploring cells with a centrifuge. Science 189: 186-194  

Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents