Isoelectric point differentiates PHF-tau from biopsy-derived human brain tau proteins

In the present study, Tau proteins were detected by two monoclonal antibodies AD2 and Tau-1 raised against PHF-tau and normal Tau proteins respectively using single- and two-dimensional immunoblotting. We demonstrate here the presence of a Tau triplet in brain homogenates from patients with Alzheimer's disease (AD) processed human brain biopsies from controls. However PHF-tau proteins have a slight but significantly higher mol. wt and a much more acidic isoelectric point. Therefore, Tau proteins are more phosphorylated in AD.