Seminal RNase: a Unique Member of the Ribonuclease Superfamily

The RNase found in bull semen, although a member of the mammalian superfamily of ribonucleases, possesses some unusual properties. Besides its unique structure and enzymic properties, it displys antispermatogenic, antitumor and immunosuppressive activities. Seminal RNase belongs to an interesting group of RNases, the RISBASES (Ribonucleases with Special, i.e. non catalytic, Biological Actions) other members of which include angiogenin, selectively neurotoxuc RNases, a lectin and the self-incopatibility factors from flowering plants.