Drugs based on cyclam, a simple cyclic molecule, show promise in the war against HIV by blocking the path of the virus into cells. Inspired by reports that zinc increased the efficacy of a cyclam-based drug, Peter Sadler and colleagues at the University of Edinburgh have shown, using spectroscopic techniques, that zinc binds rapidly to cyclam at conditions close to those found in blood. Studies of the zinc-cyclam adducts are likely to prove crucial in understanding how cyclam-based drugs are recognised by the cell. In addition, the team were surprised to find that zinc bound more rapidly than the expected favoured ion, copper, under those conditions.

Sula Armstrong