|Name||Mr. Camilo Molano|
|Organization||Florida International University|
INSIGHTS FROM TIMS-MS, IRMPD SPECTROSCOPY, AND MOLECULAR DYNAMICS ON NICOTINAMIDE ADENINE DINUCLEOTIDE STRUCTURAL DYNAMICS: NAD+ VS NADH
Juan Camilo Molano-Arevalo1; Walter Gonzales1; Kevin Jeanne Dit Fouque1; Jaroslava Miksovska1,2; Phillippe Maitre3, and Francisco Fernandez-Lima1,2*.
1 Department of Chemistry and Biochemistry, Florida International University, Miami, USA
Nicotinamide adenine dinucleotide is found in all living cells where the oxidized (NAD+) and reduced (NADH) forms play important roles in many enzymatic reactions; however, little is known about NAD+ and NADH conformational changes and kinetics as a function of the cell environment. In the present work, NAD+ and NADH were studied as a function of the organic content in solution using fluorescence lifetime spectroscopy and in the gas-phase using trapped ion mobility spectrometry coupled to mass spectrometry (TIMS-MS) and infrared multiple photon dissociation (IRMPD) spectroscopy. NAD solution, time decay studies showed a fast and slow component and dependence on the organic content. NAD gas-phase studies permitted the characterization of NAD+ and NADH structures and conformers using TIMS-MS and IRMPD. Two ion mobility bands were observed for the protonated and sodiated NAD+ species, while four and two ion mobility bands for the protonated and sodiated NADH species, respectively. IRMPD spectroscopy of NAD+ and NADH protonated species showed common and signature bands between the NAD forms. Results show that NAD+ and NADH species exist in an open, stack, and closed conformations and that the driving force for conformational dynamics is the interaction between the adenine and nicotinamide rings.