International Symposium on LifeChips 2006

Applications of a novel high density protein display technology in functional proteomics and biomarker discovery
Protein microarrays empower investigation into a broad range of biochemical properties and activities of the target proteins on the array. The strength of this approach is that by spotting many proteins on a single array, it is possible to test the functions of all of the proteins simultaneously. Without protein microarrays, these applications are tedious and expensive. They require high throughput methods to produce proteins, automation using large liquid handling robots, and highly trained personnel. Yet despite their immense potential and strong demonstrations of feasibility, protein microarrays are not widely used. In large part, this is due to the labor and technical issues associated with producing the arrays. Traditionally, arrays are assembled by producing, purifying and printing proteins onto the array surface. We developed a novel approach to generate protein microarrays by printing cDNAs onto glass slides and then translating target proteins with mammalian reticulocyte lysate. This robust method obviates the need to purify proteins, avoids protein stability problems during storage and captures sufficient protein for functional studies. This technology, Nucleic Acid Programmable Protein Array (NAPPA), is capable of producing thousands of different proteins from multiple organisms including transmembrane proteins all in a single step. Based on protein interaction studies, NAPPA recapitulated 85% of the known protein interactions demonstrating that proteins produced on NAPPA are highly functional. Using this approach, NAPPA could be readily adapted to assess the binding selectivity of small molecules to a family of related proteins (e.g., kinases) or to a mutant series of a single protein, to screen for immune responses to a large panel of antigens, or to screen for substrates for an active enzyme. NAPPA has already has demonstrated to be robust for the detection of protein-protein interactions.

Biography
Niroshan Ramachandran PhD is a research associate in the lab of Joshua LaBaer MD PhD at the Harvard Institute of Proteomics, Harvard Medical School. He has been actively involved in the development of protein microarray technology. This technology called Nucleic Acid Programmable Protein Array (NAPPA) (Science. 2004 305(5680),86-90), synthesizes an array of proteins on a solid matrix and overcomes many of the limitations of conventional protein arrays on the market today. He is currently developing this platform technology to be used for biomarker discovery in cancer. His goal is to identify informative antigens that will lead to early diagnosis of diseases and the development of vaccines for immunotherapy. Dr. Ramachandran received his Hon. BSc in 1997 from the University of Toronto, Canada. He performed his doctorate work in the area of nitric oxide metabolism in the lab of Dr. Bulent Mutus, University of Windsor, Canada. He joined the Harvard Institute of Proteomics as a post doctoral fellow in 2001.