Golden protein detectors developed

Taiwanese researchers have developed a new sensor for protein-protein interactions based on gold nanoparticles.  

Protein-protein interactions are vitally important in living organisms, playing a key role in the organisation of cells. Chao-Tsen Chen and colleagues from the National University of Taiwan have used a reversible colour change technique to evaluate these interactions. 

Chen incorporated sugar-capped gold nanoparticles with proteins; the nanoparticles mimic cells or glycoproteins in living organisms. Sugars protruding from the nanoparticles bind to a protein, causing them to agglomerate and change the colour of the solution from burgundy to blue.  

Adding another protein, thought to be able to bind to the agglomerated protein, causes a competitive reaction. The original protein-nanoparticle interactions break up giving rise to binding between the two proteins. Releasing the gold nanoparticles results in a colour change back to the original burgundy. 

The process can be monitored by the naked eye, so expensive instrumentation is not needed. This cheap, quick and sensitive method, requiring only nanomolar concentrations of proteins, can be used to analyse thousands of samples simultaneously. A broad range of proteins can be applied to the system, allowing many combinations to be investigated. 

Chen says, ’Identifying factors influencing biochemical properties, especially those that are essential to survival, would further help to understand the malfunctions of networks and find the remedy’. 

Sophia Anderton