Characterization of an amyloid beta precursor protein that binds heparin and contains tyrosine sulfate.

A secreted form of the amyloid beta protein precursor was isolated from the growth conditioned medium of the PC12 sympathetic nerve-like cell line. This protein is recognized by an antiserum that detects a protein of 140 kDa and a less abundant species of 115 kDa on NaDodSO4/acrylamide gels. The amyloid precursor proteins contain O-linked sugars and tyrosine sulfate and bind to the glycosaminoglycan heparin. These results suggest a role for extracellular sulfated glycoproteins in the pathogenesis of Alzheimer disease.