Activation of mutant β-galactosidase by antibodies can be explained by a “selection” mechanism in which the antibody binds and stabilizes those mutants in a native-like conformation and by an “induction” mechanism where binding of the antibody itself induces a conformational change activating β-galactosidase. The “selection” hypothesis was tested by passing β-galactosidase through a column packed with monoclonal antibody-derivatized Sepharose. The antibody retains the active, in preference to the inactive, proteins. The “induction” mechanism was tested by mixing antibody–Sepharose with mutant β-galactosidase and measuring enzyme activity before mixing and that remaining in the supernatant. The activity of the antibody–Sepharose pellet exceeded the sum of the original activity plus supernatant activity. As a result of these experiments, both mechanisms are found to be operative.
Beta-Galactosidase: immune recognition of conformation and mechanism of antibody-induced catalytic activation / Celada, F; Strom, Roberto. - In: BIOPOLYMERS. - ISSN 0006-3525. - STAMPA. - 22:1(1983), pp. 465-473. [10.1002/bip.360220159]
Beta-Galactosidase: immune recognition of conformation and mechanism of antibody-induced catalytic activation
STROM, Roberto
1983
Abstract
Activation of mutant β-galactosidase by antibodies can be explained by a “selection” mechanism in which the antibody binds and stabilizes those mutants in a native-like conformation and by an “induction” mechanism where binding of the antibody itself induces a conformational change activating β-galactosidase. The “selection” hypothesis was tested by passing β-galactosidase through a column packed with monoclonal antibody-derivatized Sepharose. The antibody retains the active, in preference to the inactive, proteins. The “induction” mechanism was tested by mixing antibody–Sepharose with mutant β-galactosidase and measuring enzyme activity before mixing and that remaining in the supernatant. The activity of the antibody–Sepharose pellet exceeded the sum of the original activity plus supernatant activity. As a result of these experiments, both mechanisms are found to be operative.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.