Chondroitin sulfate proteoglycan form of cellular and cell-surface Alzheimer amyloid precursor

The biological function of the amyloid precursor protein (APP) is still not fully understood. Recently, we reported that secreted truncated APP occurs in a chondroitin sulfate proteoglycan form. Here we present evidence that full length APP-chondroitin sulfate proteoglycan is present on the cell surface of C6 glioma cells. In addition, densitometric quantitation of Western blots showed that approximately 50% of the mature cell-associated full length APP is in the proteoglycan form. These findings suggest that the proteoglycan nature of APP may be important for the implementation of its biological function.