Japanese scientists have developed a new tool for analysing specific peptide-protein interactions using peptide chips. This new method uses a combination of oligonucleotide-peptide conjugate, single stranded DNA-fixed chip and acridinyl poly(ethylene glycol) (APEG). 

Shigeori Takenoka and colleagues from Kyushu University and the Kyushu Institute of Technology created a chip by anchoring a single DNA strand to a gold surface. A complementary oligonucleotide-peptide conjugate was then bound to the chip by duplex formation between the complementary DNA strands. 

Takenoka's group used APEG as a new masking reagent for the gold surface. They found that the acridine component of APEG binds the DNA duplex on gold's surface and the poly(ethylene glycol) part binds to the remaining bare gold surfaces, preventing the adhesion of any non-specific proteins. 

This combination of oligonucleotide-peptide conjugate, ssDNA-fixed chip and APEG is a new tool to analyse specific protein-protein interactions without interference by unrelated proteins. The masking of the sensor chip by APEG allows the protein-peptide interactions to be identified and quantified.

Janet Crombie