PROJECT SUMMARY The parent award is on deciphering conformational dynamics of nitric oxide synthase proteins through an integrated approach using advanced spectroscopic techniques. Detailed spectroscopic studies require milligram amounts of highly purified protein. Fast protein liquid chromatography (FPLC) is a form of liquid chromatography used to purify a target protein from a complex mixture. Our current FPLC has been a workhorse, but is near the end of operational lifetime. This administrative supplement is being requested to allow acquisition of a state-of-the-art ÄKTA pure 25 system. It has direct relevance to and immediate utility in enhancing our laboratory’s protein purification capabilities. As such, this equipment will greatly enhance our research productivity for the duration of the project, and will help us maintain a strong research program. Importantly, the unique capabilities of the ÄKTA pure 25 system will be indispensable for our efforts to develop and optimize methods for site-specifically incorporating unnatural amino acids into large, complex proteins with high fidelity, yield, and purity. Our findings will therefore be of great utility for other investigators using this process for other large, complex enzymes. Therefore, the requested equipment will help the parent project to exert a sustained, powerful influence on the research fields of bioinorganic and biophysical chemistry. Moreover, the administrative supplement will enhance the scientific environment for NIH-funded investigators at the University of New Mexico, both within and outside of the College of Pharmacy. To our knowledge, no comparable instrumentation exists in educational institutions within the region. Dean Godwin has committed substantial financial support to this supplement request since this is a great investment for the College. Taken as a whole, the proposed supplement will increase the parent award’s overall impact within the original scope of award, as well as bolster research quality and depth at our institution.