The C‐terminal region of human tau protein with ability of filament formation

Abstract

Tau protein is one of the microtubule‐associated proteins in the mammalian brain. In Alzheimer's disease, tau protein is immobilized in the somatodendritic compartment of certain nerve cells, where it forms a part of the paired helical filament (PHF). To understand the role of tau protein in the formation of PHF, a recombinant human tau protein expressed in Escherichia coli and five synthetic peptide fragments (peptide 1 to peptide 5), corresponding to the C‐terminal region of tau protein, were prepared and their ability in self‐assembly to form filamentous structures was examined. The recombrnant human tau protein formed short rod‐like structures in 0.1 M MES buffer containing 1 mM MgCl2, while a synthetic peptide fragment 1 containing 55 amino acid residues could assemble into a lot of long filamentous structures in water and particularly twisted helical structures in 0.1 M MES buffer containing 1 mM MgCl2. This suggests that the C‐terminal region possesses a filament‐forming ability and may be related ...