Abstract #4191

Studies of Quantum Mechanics/Molecular Mechanics of Small Metabolites for Quantification of Chemical Exchange Saturation Transfer

Olga Ivchenko¹,², Petra Imhof³, Moritz Zaiss⁴, Peter Bachert⁴

¹Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany; ²Molecular Biophysics, Interdisciplinary Center for Scientific Computing (IWR), Heidelberg, Germany; ³Molecular Biophysics , Interdisciplinary Center for Scientific Computing (IWR), Heidelberg, Germany; ⁴Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany

The chemical exchange rate was determined for creatine NH2 group (kex =102.9 s-1) at the pH=6.5 using quantum mechanics/molecular mechanics simulations (QM/MM) in combination with umbrella sampling simulations. This value is in agreement with the value from CEST experiment. The chemical exchange rate was determining using Arrhenius equation: