This protease inhibitor shows two different activities, it inhibits both the capsaicin receptor TRPV1 and serine proteases. It partially (max 50%) and reversibly inhibits capsaicin-induced response of TRPV1 (IC(50)=54 nM), a receptor of the pain pathway (PubMed:18579526, PubMed:24351908). The second activity is a weak inhibition of trypsin and chymotrypsin activity (Ki=1 uM and Ki=5 uM, respectively) (PubMed:18579526). In vivo, it shows antinociceptive and analgesic activities (PubMed:24351908). It significantly prolongs tail-flick latency and reduces capsaicin-induced acute pain (PubMed:18579526, PubMed:24351908). In vivo, unlike other TRPV1 antagonists whose activity is associated with hyperthermia, this protein has the remarkable feature of dropping core body temperature (PubMed:24351908). Belongs to the venom Kunitz-type family. Sea anemone type 2 potassium channel toxin subfamily.