How the Mongoose Beats the Snake

The mongoose, as anyone who has read Rudyard Kipling's Jungle Book knows, has but one purpose in life: "to fight and eat snakes." Now a team of Weizmann Institute researchers, led by Prof. Sara Fuchs of the Immunology Department, has revealed how this small mammal manages to survive the effects of deadly snake venom.

When a poisonous snake bites, venom attaches itself to a protein message receiver on the victim's muscle cells, blocking the normal flow of signals sent from the central nervous system to the cell, thus paralyzing and ultimately killing the victim.

The Institute team has found that in mongooses -- and in snakes themselves -- the structure of the receiver, the acetylcholine receptor, is slightly different from that in other animals. The difference is small -- only four out of several hundred amino acids that make up the receptor differ -- but it is enough to prevent venom from attaching itself to the cells. So mongooses like Kipling's Rikki-tikki-tavi, and snakes themselves, are protected from otherwise deadly snake attacks.

Fuchs has spent more than two decades studying the acetylcholine receptor, a protein that plays a key role in muscle function and is also involved in the autoimmune neuromuscular disorder myasthenia gravis. Part of the research was done in collaboration with Tel Aviv University's Zoology Department .