Abstract #4294

Detection of Serine Isotopomers as a Measure of Mitochondrial Function

Christopher Bryce Johnson¹, Peter Pediaditakis¹, Andrey Tikunov¹, Douglas Romney², Haakil Lee¹, Ekhson Holmuhamedov^2,3, Mike Gamcsik⁴, Jeffrey MacDonald¹

¹Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; ²Cell Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; ³The Center of Theoretical Problems of Physico-Chemical Pharmacology, Moscow, Russian Federation; ⁴Biomedical Engineering, North Carolina State University, Raleigh, NC, USA

The glycine cleavage system (GCS), which is found exclusively in mitochondria, converts glycine to methylene tetrahydrofolate (mTHF), and serine hydroxymethyltransferase (SHMT) uses the mTHF to form serine. A SHMT isoform also exists in the cytosol. When 2-13C glycine is used in place of unlabeled glycine, two pools of serine are formed, a 3-C labeled serine from the mitochondria and a 2-C labeled serine from the cytosolic. We show that MRS can detect the resulting serine pools, and we hypothesize that by analyzing these pools this method can be uses as a non invasive, in vivo detection system of mitochondrial function.