Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Concanavalin A Derivatives with Altered Biological Activities

Gary R. Gunther, John L. Wang, Ichiro Yahara, Bruce A. Cunningham and Gerald M. Edelman
Proceedings of the National Academy of Sciences of the United States of America
Vol. 70, No. 4 (Apr., 1973), pp. 1012-1016
Stable URL: http://www.jstor.org/stable/62412
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Concanavalin A Derivatives with Altered Biological Activities
Preview not available

Abstract

Chemical derivatization of tetrameric concanavalin A (Con A) with succinic anhydride or acetic anhydride converts the protein to a dimeric molecule without altering its carbohydrate-binding specificity. At low concentrations, the dose-response curves for the mitogenic stimulation of mouse spleen cells by native Con A and succinyl-Con A are similar. Above lectin concentrations of 10 μ g/ml, however, the response to Con A is diminished, while that for succinyl-Con A does not decrease until much higher doses are reached. We have attributed this difference mainly to the higher rate of cell death induced by the native Con A molecule. Con A also shows a greater capacity than succinyl-Con A to agglutinate sheep erythrocytes and to inhibit cap formation by immunoglobulin receptors on spleen cells. Moreover, at low concentrations, Con A induced its glycoprotein receptors to form caps, but succinyl-Con A did not induce cap formation. Addition of antibodies directed against Con A to succinyl-Con A bound on cells restored the properties of agglutination, inhibition of immunoglobulin receptor cap formation, and induction of cap formation by Con A receptors. Similar results have been obtained for acetyl-Con A. These data suggest that the altered biological activities of succinyl-Con A and acetyl-Con A are attributable to their reduced valence.

Page Thumbnails

  • Thumbnail: Page 
1012
    1012
  • Thumbnail: Page 
1013
    1013
  • Thumbnail: Page 
1014
    1014
  • Thumbnail: Page 
1015
    1015
  • Thumbnail: Page 
1016
    1016