Skibinski G, Kelly R W, James K
Department of Surgery, University of Edinburgh Medical School, Scotland.
Fertil Steril. 1994 Apr;61(4):755-9. doi: 10.1016/s0015-0282(16)56658-8.
To further characterize prostasomes, trilamellar to multilamellar vesicles that are thought to originate from acinar cells of the human prostate and present in appreciable amounts in normal human semen. Purified prostasomes were shown to have immunosuppressive activity in vitro as measured by inhibition of mitogen-induced lymphocyte proliferation and inhibition of superoxide generation by neutrophils. A granule membrane protein, called granulophysin, has recently been identified in the membranes of platelet dense granules. Antibodies that recognize granulophysin also stain granules in different cell types including leukocytes, melanocytes, neurones, endothelial cells, and epithelial cells.
The presence of epitopes recognized by antigranulophysin monoclonal antibody in prostasomes was investigated using indirect immunofluorescence and subsequent cytofluorimetric analysis. The protein was also analyzed by Western blotting. Reactivity of antigranulophysin antibody with the prostate tissue was studied by immunoperoxidase staining.
A majority of prostasome particles specifically reacted with antigranulophysin antibody. In lysates prepared from prostasomes, a broad band of 32 to 37 kd was detected by Western blotting.
This report defines granulophysin as a constituent membrane molecule of prostasomes that may serve as a useful marker in elucidation of prostasome function.
