This animation illustrates how a small molecule binds to a protein. As a result of the binding, the protein alters its shape and becomes inactivated.
Rapamycin is a small molecule originally isolated from nature. It has antibiotic and immunosuppressive properties. It also allows two proteins which do not normally interact to bind together in the cell, which causes problems in the nutrient-sensing pathway.
To understand life's processes, perturb them. How a process responds to an insult can provide clues about normal function or mimic a specific disease state.
Scientists now have the ability to create millions of new molecules. How do they test whether any of these molecules are useful?