Thomas Kodadek and Yong-Uk Kwon from the University of Texas Southwestern Medical Centre in the US, have developed a 'one bead two compound' strategy for the creation of cyclic peptoid microarrays. Each bead contains a linear and cyclic molecule containing the same peptide sequence. Only the cyclic peptoid contains a cysteine and can be spotted onto a maleimide-activated slide for use in screening experiments. 

                   

There is great interest in discovering small molecules that bind to proteins with high affinity and specificity as they have applications ranging from drugs to antibodies in biotechnology. 

Kodadek's team is focused on peptoids that can recognize protein-protein interaction surfaces to which other small molecules do not bind well. 

The long term motivation 'was to provide us with a tool to compare the protein binding properties of linear and cyclic peptoids to proteins as well as provide a convenient screening platform for the discovery of new protein ligands,' says Kodadek. 

In the future, Kodadek hopes to adapt the technology so that far more small molecules can be screened at the same time, as at present the microarray format limits the number of compounds that can be screened to about 20,000. 

Michael Brown