Meir Wilchek

Affinity therapy, or immunotoxins is a biorecognition-based approach to selectively deliver a cytotoxic drug or toxin to a specific target cell. The field of affinity therapy was pioneered by Wilchek, together with Michael Sela, Ester Hurwitz, and Ruth Arnon. In 1975, they applied drug-conjugated antibodies for the targeted delivery of cytotoxic compounds to cancer cells. They also demonstrated the advantage of having a polymeric spacer between the antibody and the drug and showed the effectiveness of conjugating simple polymers such as dextran for drug delivery and targeting. This approach was later adopted by others and eventually led to efficient treatment of human breast cancer by recombinant humanized anti-HER2 antibody (Herceptin) in a mixture with paclitaxel and doxorubicin. In 2003, Wilchek collaborated in a team who introduced a system based on antibody-directed enzyme prodrug therapy (ADEPT), using antibody-conjugated alliinase to produce a cytotoxic agent, allicin, in situ (at the site) of the cancer

In 1971, Wilchek and colleagues applied this method to show that protein kinase is composed of regulatory and catalytic subunits. In 1972, Wilchek showed that the method can be used to remove toxic compounds from blood, as exemplified by the removal of heme peptides from blood using immobilized human serum albumin, thus laying the grounds for modern hemoperfusion

The avidin–biotin system is a technique for studying the interaction between two biomolecules in an indirect manner, as follows: Biotin is chemically coupled to a binder molecule (e.g., a protein, DNA, hormone, etc.) without disturbing the interaction with its target molecule; avidin is then used to “sandwich” between the biotinylated binder and a reporter molecule or probe. This allows for a variety of tasks, including localization and identification of the binder or target molecule. Consequently, the avidin-biotin system can frequently replace radioactive probes. Together with Ed Bayer, Wilchek established the Avidin-biotin system as a powerful tool in biological sciences. Early in the 1970s, they exploited Avidin as a probe and developed new methods and reagents to biotinylate antibodies and other biomolecules. Today, the system is applied in research and diagnostics as well as medical devices and pharmaceuticals. Examples include western blot, ELISA, ELISPOT and pull-down assays. More recently, Wilchek participated in structural studies of the avidin–biotin complex, to characterize the unique properties of this strong interaction. The studies have culminated in the determination of the 3D structure of the avidin–biotin complex by X-ray crystallography, which aids in the design of specific artificial recognition sites.

Meir Wilchek was born in Warsaw, Poland, scion of a rabbinical family. During the Holocaust, he escaped from the German-occupied territories to the territories occupied by Russia, and was transferred to Siberia, while his father, who served as a community rabbi in Warsaw, was killed in Flossenbürg concentration camp. He survived, and immigrated to Israel in 1949 with his mother and sister. He graduated with B.Sc. in chemistry from Bar Ilan university and Ph.D. in biochemistry from the Weizmann Institute of Science. Wilchek has published over 400 scientific papers, and consulted various biotech companies. He was also in the party list of Mafdal and Meimad for the Knesset.

Meir Wilchek (Hebrew: מאיר אשר וילצ'ק, born 17 October 1935) is an Israeli biochemist. He is a professor at the Weizmann Institute of Science.