Enhanced kinase sensing by radio-phosphorylation and oriented immobilization of a GBP-linked kinase substrate on a gold surface

A new strategy for enhanced sensing of kinases was developed using radio-phosphorylation and a polypeptide with an affinity for gold that was linked directly to kinase substrates. Gold-binding polypeptide (GBP)-linked GST-fusion substrates were efficiently immobilized on gold-coated slides, which is highly desirable for protein chips. The novel fusion substrates permitted oriented substrate immobilization on gold-coated slides, thereby enhancing the sensitivity of kinase assays. Thus, the proposed strategy is applicable to the development of protein microarrays and microfluidic lab-on-a-chip (LOC) sensing the activities of protein kinases.