Seminal plasmin, a bovine seminal plasma protein, lyses dividing but not resting mammalian cells

Seminal plasmin, an antimicrobial and transcription-inhibitory protein of bovine seminal plasma, is shown to lyse dividing mammalian cells in vitro. It lyses cells in culture such as CHO, Vero, HeLa and L929. It also lyses regenerating rat liver parenchymal cells and cells of two ascitic tumours of rat--the Zajdela ascitic hepatoma and the AK-5. However, it does not lyse resting cells such as adult liver parenchymal cells, erythrocytes, or resting lymphocytes, though it binds to their cell surface. It can be used, therefore, to distinguish cells that are in the division cycle from cells that are in the resting phase. The cell-lytic activity of seminal plasmin is inhibited by Ca2+.