ARTICLE

THE DISTRIBUTION AND ASYMMETRY OF MAMMALIAN CELL SURFACE SACCHARIDES UTILIZING FERRITIN-CONJUGATED PLANT AGGLUTININS AS SPECIFIC SACCHARIDE STAINS

¹ From the Cancer Council and Electron Microscopy Laboratories, Armand Hammer Cancer Center, The Salk Institute for Biological Studies, San Diego, California 92112 and the Department of Biology, University of California at San Diego, La Jolla, California 92037

The preparation, properties, and some applications of ferritin conjugates of two plant agglutinins, concanavalin A and Ricinus communis agglutinin, are reported. These conjugates serve as specific electron-dense stains for cell- and membrane-bound saccharide residues of the -D-mannopyranosyl and ß-D-galactopyranosyl configurations, respectively, and as examples of a wide range of ferritin-plant agglutinin conjugates useful as high resolution saccharide stains. By using a technique for preparing flattened membrane specimens, it was found with a variety of mammalian cell plasma membranes (lymphocyte, lymphoma, and myeloma and normal, spontaneously and virally transformed fibroblasts) that the ferritin conjugates were localized exclusively to the exterior face of the membrane, with essentially none found on the cytoplasmic face. On the exterior face the topographical distribution of ferritin conjugates appeared to be random. The asymmetrical distribution of saccharide residues to the outer membrane face can be explained by an "assembly line" process whereby new plasma membrane is made from intracellular precursor membranes. It also suggests that the saccharide-containing components of the plasma membrane do not rotate at any appreciable rate from one membrane surface to the other.

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

This article has been cited by other articles:

• Rothman, J., Lenard, J (1977). Membrane asymmetry. Science 195: 743-753 [Abstract]  
• Fishman, P., Brady, R. (1976). Biosynthesis and function of gangliosides. Science 194: 906-915 [Abstract]  
• Lennarz, W. (1975). Lipid linked sugars in glycoprotein synthesis. Science 188: 986-991  
• Nicolson, G. L., Yanagimachi, R. (1974). Mobility and the Restriction of Mobility of Plasma Membrane Lectin-Binding Components. Science 184: 1294-1296 [Abstract]  

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