Protein microarray using a-amino acids as metal tags on chips

Procedures for synthesizing a-amino acids on a chip for coordination with transitional metal ions and a His-Tagged protein have been successfully developed as a stable protein microarray. Using the recombinant His-Tagged 3CL-protease (3CL) as a model for attachment to chips containing D-/L-Glu, Asp, Orn, Ser via different transitional metal ions, it was found that the Orn chip was the best of affinity binding and stability by which Zn was the best metal ion for affinity while Co was the best metal ion for stability. Thus, this protein microarray can be alternatively used as a high throughput screening method for rapid detection against SARS CoV 3CL and/or efficient purification of other Tagged proteins. 2005 Elsevier Ltd. All rights reserved. Immobilized metal affinity chromatography (IMAC) is a separation technique that uses covalently bound chelating compounds on solid chromatographic supports to entrap metal ions, which can serve as affinity ligands for various proteins. Although IMAC is widely used for the separation of proteins having exposed histidine groups, most of used ligands are immobilized on the solid supports as resins or acrylamides in the columns. Recently, microarray has been developed as a high throughput technique for proteomic and genomic analysis; for example, proteins bound to ligands on surfaces have been used to detect protein–protein interactions, enzymatic substrates, and protein–small molecule interaction. However, development of this approach for site-specific immobilization of proteins onto chip surfaces still represents a significant challenge. In this study, we describe a new procedure to prepare arrays for proteomic analysis, which combines two techniques be0960-894X/$ see front matter 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.bmcl.2005.01.001