Peptide microarrays for the detection of molecular interactions in cellular signal transduction

The formation of protein complexes is a hallmark of cellular signal transduction. Here, we show that peptide microarrays provide a robust and quantitative means to detect signalling‐dependent changes of molecular interactions. Recruitment of a protein into a complex upon stimulation of a cell leads to the masking of an otherwise exposed binding site. In cell lysates this masking can be detected by reduced binding to a microarray carrying a peptide that corresponds to the binding motif of the respective interaction domain. The method is exemplified for the lymphocyte‐specific tyrosine kinase 70 kDa zeta‐associated protein binding to a bis‐phosphotyrosine‐motif of the activated T‐cell receptor via its tandem SH2 domain. Compared to established techniques, the method provides a significant shortcut to the detection of molecular interactions.