Distribution of lysosomal protective protein in human tissues.

We raised two polyclonal antibodies against synthetic oligopeptides comprising amino acid sequences in the human lysosomal protective protein. The first antibody recognized the 54-kDa precursor and the N-terminal sequence of the 32-kDa mature protein subunit, and the second one recognized the precursor and the C-terminal sequence of the 20-kDa subunit. In normal fibroblasts, mature protective protein was detected on immunoblotting with these antibodies. Considerable amounts of mature protective protein also were detected in kidney, lung, liver, and spleen, but not in brain from a patient with Gaucher disease. Neither the precursor nor the mature protective protein was detected in cultured fibroblasts, liver or cerebrum from a galactosialidosis patient with protective protein deficiency.