Concanavalin a perturbation of membrane enzymes of mammary gland

✍ Scribed by Carraway, Coralie A. ;Carraway, Kermit L.

• Book ID: 102438419
• Publisher: Wiley (John Wiley & Sons)
• Year: 1976
• Tongue: English
• Weight: 339 KB
• Volume: 4
• Category: Article
• ISSN: 0091-7419
• DOI: 10.1002/jss.400040111

✦ Synopsis

Abstract

The plant lectin concanavalin A (Con A) specifically inactivates the 5′ ‐nucleotidase of a plasma membrane‐enriched fraction from lactating mammary gland. The lectin also causes an activation of the membrane Mg^++^ ‐ATPase, but does not affect galactosyltransferase or alkaline phosphatase. The enzyme perturbations are prevented by α‐methylmannoside, an inhibitor of Con A binding, indicating that specific binding to carbohydrate structures rather than nonspecific protein‐protein interaction is involved. Solubilization of the 5′ ‐nucleotidase in detergents (0.2% Triton X‐100 or 1% deoxycholate) does not prevent Con A inactivation, indicating that incorporation into the membrane structure is not a requirement for the Con A effect. The results suggest that Con A inactivates the 5′ ‐nucleotidase by a direct interaction with the enzyme and that this enzyme is a Con A receptor site on the surface of mammary cells.