Researchers discover new binding sites for active agents on cell cytoskeleton Through a unique combination of computer simulations and laboratory experiments, researchers at the Paul Scherrer Institute PSI have discovered new binding sites for active agents - against cancer, for example - on a vital protein of the cell cytoskeleton. Eleven of the sites hadn't been known before. The study appears today in the journal Angewandte Chemie International Edition. The protein tubulin is an essential building block of the so-called cell cytoskeleton. In cells, tubulin molecules arrange themselves into tube-like structures, the microtubule filaments. These give cells their shape, aid in transporting proteins and larger cellular components, and play a crucial role in cell division.