Daboia siamensis Kunitz-type serine protease inhibitor (KSPI)

Daboia siamensis Kunitz-type protease inhibitor toxins are a major family of small, disulfide-rich proteins (approximately 60 amino acids) found in the venom of the Eastern Russell's viper (UniProt A8Y7N5, P00990). These toxins function as potent inhibitors of various serine proteases, including trypsin, chymotrypsin, and plasmin, thereby disrupting the host's hemostatic system and contributing to severe coagulopathy and hemorrhage (PMC9325154, PMC7003344). While they are critical components of the venom's toxic profile, they also serve as the primary targets for neutralization by monovalent and polyvalent antivenoms during clinical treatment of snakebites (MDPI Toxins 2023, 15(1), 54). Beyond their role in envenomation, these Kunitz-type peptides are being actively researched for their potential therapeutic applications, particularly as anti-tumor and anti-angiogenic agents due to their ability to modulate signaling pathways and inhibit protease-mediated cell invasion (PMC8912144). However, their small size and low immunogenicity can pose significant challenges for achieving effective neutralization with standard antivenom therapies (PMC7003344).

Other names

Kunitz-type serine protease inhibitorVenom basic protease inhibitorTrypsin inhibitorChymotrypsin inhibitorBPTI-like toxinRVV-IIVKT2_DABSIVKTC2_DABSIVKTB3_DABSIVKTB1_DABSI

Antibody-mediated neutralization of toxin activity and competitive inhibition of host serine proteases.