Reality Bites

According to popular myth, poisonous snakes immobilize their prey through hypnosis before going in for the kill. On the molecular level, snake venom does something similar: it immobilizes a protein known as the acetylcholine receptor which plays a crucial role in nerve-muscle communication. A Weizmann Institute of Science study published in the Proceedings of the National Academy of Sciences (June 12, Vol. 94, p. 6054) has pinpointed - with greater precision than previous studies - the exact spot at which cobra venom latches on to the acetylcholine receptor. In the future, this finding may make it possible to develop a synthetic antidote to protect the lives of cobra bite victims.

A synthetic antidote could protect just that tiny spot, preventing the venom from latching on to the receptor. It would be more effective and faster- acting than the current method of treatment, which involves injecting the victim with horse serum containing antibodies against the venom. Moreover, the synthetic molecule would eliminate the risk of allergy associated with serum therapy.

In the study, Prof. Sara Fuchs of the Immunology Department, Institute Professor Ephraim Katchalski-Katzir and Dr. Moshe Balass of the Membrane Research and Biophysics Department zeroed in on a peptide (protein fragment) that makes up a tiny fraction of the acetylcholine receptor - a dozen amino acids out of some 2,000 - yet is crucial for the binding between the receptor and a particular toxin in the cobra venom.

To achieve this goal, the researchers searched through a huge "library" of random peptides until they identified the one peptide that had the strongest interaction with the toxin. In a parallel study reported in the same issue of PNAS, Prof. Jacob Anglister and Dr. Tali Scherf of the Structural Biology Department, together with Balass, Fuchs and Katzir, used nuclear magnetic resonance spectroscopy to describe the structural aspects of binding between the protein fragment and the snake toxin.

Additional Information

Prof. Fuchs holds the Prof. Sir Ernst B. Chain Chair of Neuro-Immunology, and Prof. Katzir, the Theodore R. Racoosin Chair of Biophysics. Their research was supported by grants from the Rashi Foundation, Israel's Ministry of Science, the Israel Science Foundation administered by the Israel Academy of Sciences and Humanities, the Muscular Dystrophy Association of America, the Association Franחaise Contre les Myopathies, and the Leo and Julia Forchheimer Center for Molecular Genetics at the Weizmann Institute of Science. Prof. Anglister's work was supported by the U.S.-Israel Binational Science Foundation.

The Weizmann Institute of Science is a major center of scientific research and graduate study located in Rehovot, Israel.