huwentoxin-I

Huwentoxin-I (HWAP-I) is a 33-amino acid peptide toxin originally isolated from the venom of the Chinese bird spider (*Haplopelma huwenum*, also known as *Cyriopagopus schmidti*). It functions as a potent and selective antagonist of N-type voltage-gated calcium channels (CaV2.2). These channels are primarily located in the presynaptic terminals of primary afferent neurons in the dorsal horn of the spinal cord, where they play a critical role in the transmission of pain signals. By blocking CaV2.2, HWAP-I inhibits the release of pro-nociceptive neurotransmitters such as glutamate and substance P, thereby providing significant analgesic effects. Developed by Xiamen Beida Zhi Road Bioengineering, HWAP-I has been investigated in clinical trials for the management of severe chronic pain, particularly cancer-related pain, as a non-opioid alternative with a mechanism of action similar to ziconotide.

Other names

Huwentoxin-I虎纹镇痛肽