IS AMYLOID BETA-PROTEIN GLYCATED IN ALZHEIMERS-DISEASE

RECENT data suggest that protein glycation is involved in the process of amyloid formation in Alzheimer's disease (AD). To further investiga te this issue, we analyzed the presence of advanced glycation end prod ucts (AGE) in soluble and insoluble forms of amyloid B-protein (AP) as well as in apolipoprotein E (apoE), a protein bound to amyloid deposi ts. Both proteins were extracted from cerebral cortex obtained from pa tients with AD and probed by immunoblotting with two antibodies specif ic for different AGE, already known to immunocytochemically label amyl oid plaques. All the AGE antibodies failed to recognize either AP or a poE, whereas they reacted with synthetic AP glycated in vitro. These f indings indicate that other proteins associated with amyloid deposits are candidates to be modified with AGE in Alzheimer's cerebral tissue.