The activity of proteases -- enzymes that cut other proteins and are important in diseases such as AIDS and cancer -- can be imaged in living animals with 'smart probes' using a method reported in the October 2007 issue of Nature Chemical Biology. Cathepsin proteases are specific protein-cleaving enzymes involved in tumour formation and metastasis, and are important targets for diagnosing and treating cancer.
Using probes that only fluoresce when they react with active proteases, Matthew Bogyo and colleagues have imaged cathepsin activity in the tumours of living mice. Because the probes form a covalent bond (a permanent connection) with cathepsin, in vitro experiments can directly follow in vivo imaging to provide a mechanistic explanation for what is observed. The authors demonstrate that these probes are useful for testing the effectiveness of potential drugs.
Matthew Bogyo (Stanford University, Stanford, CA, USA)
Abstract available online.
(C) Nature Chemical Biology press release.
Message posted by: Trevor M. D'Souza