Bovine seminal ribonuclease (BS-RNase)

Bovine seminal ribonuclease (BS-RNase) is a unique member of the ribonuclease A (RNase A) superfamily, primarily found in bovine seminal plasma. It is distinguished by its quaternary structure, existing as a covalent homodimer linked by two disulfide bonds, which allows it to evade the cytosolic ribonuclease inhibitor (RI) that typically inactivates other RNases (Source: UniProt, PubMed: 11514142). This evasion enables BS-RNase to exert potent biological effects, including selective anti-tumor activity and immunosuppression, by degrading intracellular RNA and inducing apoptosis in malignant cells (Source: PubMed: 15563287). While it has been extensively studied as a potential chemotherapeutic agent due to its ability to target cancer cells with high metabolic activity, its clinical application is challenged by its bovine origin, which may trigger immunogenic responses in humans (Source: PubMed: 10658347). Research continues to focus on engineering humanized versions or variants with improved stability and reduced toxicity for therapeutic use in oncology (Source: PubMed: 22403078). Its mechanism involves cellular internalization followed by the degradation of ribosomal RNA, making it a potent inhibitor of protein synthesis in target tissues.

Other names

Seminal ribonucleaseRibonuclease 2RNase BSBovine seminal RNase

Bovine seminal ribonuclease (BS-RNase) exerts its biological effects through its ribonucleolytic activity. It exists as a mixture of two dimeric forms (M=M and M+M) held together by disulfide bridges. This dimeric structure is crucial as it prevents the protein from being inhibited by the ubiquitous cytosolic ribonuclease inhibitor (RI). After being internalized by cells through endocytosis, BS-RNase reaches the cytosol where it degrades ribosomal RNA (rRNA), leading to the cessation of protein synthesis and the induction of apoptosis, particularly in rapidly dividing cancer cells (Source: PubMed: 11514142, 15563287).