[The role of carbohydrate groups in IgM. VIII. The effect of treatment of IgM with acids on the subsequent action of glycosidases and endogenous proteinases].

Exposure of IgM to acidic medium (pH approximately 3, 30 min, at 20 degrees) and subsequent returning to neutral conditions leads to irreversible changes in the state of the molecule. This results in the loss of IgM accessibility for the action of glycosidases and, at the same time, makes it more susceptible to the action of proteinases. Both effects are thought to be due to an irreversible conformational rearrangement of IgM in acidic medium.