Is it possible for microorganisms to ferment snake venom?

• Researchers traced the source of a toxin called kininase serine protease to a common ancestor salivary protein

• The results of the evolutionary tree also showed that mammalian non-toxic salivary kinins, including those found in mouse and human saliva, also evolved from the same ancestral genes

• This study provides strong evidence for the hypothesis that the venom evolved from a set of potentially toxic common genes that existed in the ancestors of snakes and mammals.

  
  

Snakes, some lizards, and even some mammals release venom

Researchers from the Okinawa Institute of Science and Technology (OIST) in Japan and the Australian National University focused on a class of toxins found in most snake venom and all other reptile and mammalian venoms called kallikrein serine proteases, their origin Go back to the discovery of a common ancestor in genes

"Venom is a mixture of toxic proteins that have evolved throughout the animal kingdom, and is usually a method of killing or fixing prey," explained Agneesh Barua, a PhD student and co-first author at OIST

Salivary kinins, like the kinins found in mice, humans, and toxic mammals like shrews and solenoids, are closely related to the toxic serine protease kinins found in venomous snakes

In a previous paper, Barua and his colleagues found that mammalian salivary glands and snake venom glands have similar activity patterns in a set of regulatory genes, indicating that the basis for snake venom evolution exists in both snakes and mammals

"In that paper, we hypothesized that in the ancestors of snakes and mammals, a common set of genes was potentially toxic," Barua said

Kallikrein serine proteases (Kallikrein serine proteases) is a protein degrading enzyme that plays a key role in regulating blood pressure

Earlier, researchers noticed that the kininase serine protease in snake venom is biochemically similar to the serine protease in mammalian saliva, but until now scientists have not known whether they are really related

With the latest advances in genomic methods, the research team was able to identify and compare all kininase genes in reptiles, amphibians, fish, and mammals to create an evolutionary tree

Excitingly, they found that snake venom kininase serine protease and mammalian salivary kininase indeed evolved from the same ancestral gene

Barua said: "This is very strong evidence for our hypothesis that the venom evolved from a common set of genes of potentially toxic ancestors

In fact, researchers have discovered that the non-toxic kinins in mammalian saliva are more closely related to the toxic toxins in snakes than other kinins in mammals

In general, this evidence shows that the salivary kininase protein of mammals (including humans) also has the potential to evolve into toxic substances

However, Barua quickly added that there was a caveat

But he said this does tell us that the line between toxic and non-toxic mammals is more blurred than previously thought

Reference: "Co-option of the same ancestral gene family gave rise to mammalian and reptilian toxins" 22 December 2021, BMC Biology .

DOI: 10.
1186/s12915-021-01191-1