Proteins in snake venom and human saliva evolved from the same ancestral gene

Anita Durairaj

An interesting research study conducted by scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) in Japan and the Australian National University led to the discovery that humans and snakes may have something in common.

The researchers were studying a class of toxins found in snake venom called kallikrein serine proteases. Kallikreins are protein-degrading enzymes that are involved in the regulation of blood pressure.

Independent of the kallikreins found in snake venom, the saliva of some mammals including humans also tends to contain kallikreins. The exception here is that human saliva contains non-toxic salivary kallikreins while in snakes and other mammals, the kallikreins have evolved to become toxic.

The researchers were interested in determining the genetic history of the kallikreins from both snakes and mammals to determine their ancestral genes.

As described in Science Daily, the significance of their findings lay in the fact that the non-toxic kallikreins found in humans and other mammals evolved from the same ancestral gene as the venomous kallikreins found in snakes.

Potentially, this has interesting implications for human physiology in an evolutionary sense. According to Science Daily, it would mean that humans could also develop venomous kallikreins in the same manner as snakes. However, the chances of this happening would be negligible as there is no ecological or evolutionary pressure for humans to develop venom in their saliva.

The research study simply hints that this could theoretically be possible.

For now, humans and snakes may have more in common than previously thought.


Okinawa Institute of Science and Technology (OIST) Graduate University. "Venoms in snakes and salivary protein in mammals share a common origin." ScienceDaily. ScienceDaily, 23 December 2021.

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Trained with a Ph.D. in Chemistry from the University of Cincinnati, I write unique and interesting articles focused on science, history, and current events.


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