Two-dimensional gel electrophoresis of human brain proteins. IV. Disorders of glial proliferation and a polymorphism of glial fibrillary acidic protein--GFAP Duarte.

Several genetic and non-genetic neurological disorders are characterized by neuronal cell death, followed by astrocytic glial cell proliferation. Because the major intermediate filament in astrocytes is glial fibrillary acidic protein (GFAP), large amounts of this protein accumulate. The two-dimensional gel-electrophoretic pattern of gliosed tissue is described. It shows a massive accumulation of the 50 000-dalton GFAP charge isomers (8e:1--8) plus a series of breakdown products of lower molecular mass and more-acid charge. In addition, I describe a genetic polymorphism, GFAP-Duarte, presenting as an additional, basic charge isomer of GFAP. The possibility that this or other mutations of GFAP may predispose certain neurons to premature cell death is discussed.