[Direct demonstration of abnormal phosphorylation of Tau microtubular proteins in Alzheimer's disease].

Two polyclonal antibodies, the first raised against Alzheimer's disease PHF and the second raised against human native Tau proteins, led us to find two Tau proteins with an abnormal molecular weight of 64 and 69 kDa in Alzheimer brain cortices. Tau 64 and Tau 69 were never detected in control brains. The molecular weight of Tau 64 and 69 dramatically decreased after dephosphorylation by the alkaline phosphatase, showing that they are abnormally phosphorylated. This is the first report demonstrating their specific presence in brain regions having the Alzheimer pathology. They could be a very useful tool for the study of the early events that lead to neuronal death.