Since the isolation by Heppel & Hilmoe (1955) of 5′-nucleotidase from bull seminal plasma, several papers on its biochemical properties in the semen of bulls and other animals have been published (Mann, 1964; Levin & Bodansky, 1966; Pilcher & Scott, 1967; Buruiana & Dema, 1968; Strzeẓek & Wołos, 1972; Strzeẓek, Wołos & Glogowski, 1972). Unfortunately, the results of the studies have, in many cases, been contradictory, and the rôle of the enzyme in semen is still unclear.
This study is a further attempt to describe the biochemical and immunological characteristics of the 5′-nucleotidase separated from bull seminal plasma.
Bull semen collected by artificial vagina was centrifuged twice for successive 15-min periods at 12,800 g . Seminal plasma was stored at a temperature of −20°C. Isolation of 5′-nucleotidase (EC 220.127.116.11) was carried out by the method described by