The bite of a Brazilian wandering spider might not kill you, but it can make you wish you were dead. The cocktail of toxins in its venom produces a suite of not-so-delightful effects like swelling, intense pain and paralysis. If you're male, you also get a painful erection that lasts for hours.
The unending erection part caught the attention of medical researchers several years ago, and they isolated the part of the venom that triggers those symptoms, a complex peptide called PnTx2-6. Injecting rats with PnTx2-6 produced erections, but also caused nasty side effects like lung and heart congestion. An international team of researchers led by Maria de Lima of the Federal University of Minas Gerais has now found that a protein built from a small part of PnTx2-6 can produce long-lasting erections without the side effects.
The synthesised protein, called PnPP-19, seems to make erectile tissue inflate by increasing the amount of nitric oxide in the tissue. That means it works on a different part of the physiological pathway that gets erection going than drugs like Viagra do, and that's important because up to a third of men suffering from impotence either don't respond to the drugs that are currently on the market or can't take them due to other life-threatening health conditions.
Pictures: João P. Burini via Wikimedia