Ssm6a

Ssm6a is purified from the venom of the Chinese red-headed centipede, Scolopendra subspinipes mutilans, found in Southeast Asia.

Ssm6a shares only 40% of identity with its most related protein, κ-SLPTX-Ssm1, another toxin recently isolated from the venom of the same centipede.

[2] This structure is very similar to an inhibitor cystine knot, commonly found in invertebrate toxins.

Ssm6a show a significantly higher efficiency than morphine in response to induced abdominal writhing (by injection of acid) and thermal pain (by photothermal heat).

Ssm6a is now considered as a potential morphine substitute, due to its analgesic properties, and apparent lack of side effects.