The Riddle of the Molecular Machine

Every time we breathe, the oxygen drawn into our lungs binds to iron atoms present in hemoglobin molecules in the blood; in so doing, it "hitches a ride" along the circulatory system. The hemoglobin molecules transport the oxygen to cells throughout the body, where the oxygen is released and used to produce energy - which demonstrates just how vital the reactions of binding and releasing oxygen are to life.

Iron's ability to bind, release, and activate oxygen stems from its capacity to "give" and "receive" electrons. In this respect, it is similar to other metals such as copper, cobalt, and nickel. These metals underlie the actions of numerous enzymes - "molecular machines" that set the processes of life in motion. The metals' mode of operation is highly dependent on the "context," that is, the environment and structure of the enzyme's active site. In one case, for instance, iron merely transports oxygen, while in another it activates it, thus enabling the oxidation of the organic substrate, which is essential for the detoxification processes performed by the liver.

Prof. Daniella Goldfarb, Head of the Weizmann Institute's Chemical Physics Department, aims to map the precise structure of the metal-containing active sites within enzymes so as to mimic them, thus potentially enabling the construction of "molecular machines" that could perform diverse industrial functions. Mapping these sites may also lead to methods for "fixing" damaged enzymes, offering an invaluable medical tool, since damaged or faulty enzymes lie at the root of many diseases.

In her research, Goldfarb uses advanced electron resonance methods and instruments she has helped develop, some built at the Weizmann Institute according to her specifications.

Prof. Daniella Goldfarb's research is supported by the Fritz Haber Center for Physical Chemistry.