Solution NMR Study of Serum Albumin as an Anandamide-Binding Protein Yong Yang, Han Zhou, Trisha A. DÍArriola, Sergiy I. Tyukhtenko, Jianqin Zhuang, De-Ping Yang, Spyros P. Nikas, Jianhong Zhao, Jianxin Guo, and Alexandros Makriyannis Center for Drug Discovery, Northeastern University æThe cellular uptake and intracellular transport of the endocannabinoid anandamide (arachidonoylethanolamine, AEA) are essential for controlling its extracellular levels in the brain. Recently, serum albumin was identified as an AEA-binding protein that may be responsible for carrier-mediated trafficking of anandamide within the cytosol. To explore these early findings, we have developed a method to rapidly screen ligands including a range of endocannabinoids using several characteristic downfield 1H-NMR resonances from albumin. In particular, our NMR data showed that the binding of anandamide to albumin is specific, and we are now in the process of identifying these specific AEA-binding sites on HSA. Additionally, we have characterized the interactions of HSA with AM5206 and several other fatty acid amide hydrolase (FAAH) inhibitors using 19F-NMR. Further experiments are also underway to identify ligands that can compete effectively with anandamide for binding with albumin. ææAcknowledgements: This work was supported by NIH grants DA003801 (A.M.), DA007215 (A.M.), DA007312 (A.M.), and DA032020 (J.G.) from the National Institute on Drug Abuse.