EPR spectroscopy and theoretical study of gamma-irradiated asparagine and aspartic acid in solid state.
Aspartic acid (Asp) and asparagine (Asn) are vulnerable amino acids. One-electron addition or withdrawal reactions initiate many deleterious processes involving these amino acids. To study these redox processes we have irradiated by gamma-rays asparagine or aspartic acid in the solid state. The nature of the resulting free radicals was determined by electron paramagnetic resonance (EPR) and by calculations using DFT methods in various environments. Reactions initiated by electron transfer are different for both amino acids: Asn anion loses hydrogen atom whereas the cation undergoes decarboxylation. Conversely, Asp cation loses hydrogen atom from amine group, which triggers decarboxylation.
Strzelczak
Grazyna
G
Institute of Nuclear Chemistry and Technology, 03-195 Warsaw, Poland.
Bergès
Jacqueline
J
Houée-Levin
Chantal
C
Pogocki
Dariusz
D
Bobrowski
Krzysztof
K
D001216:Asparagine / Q000737:chemistry / Q000528:radiation effects*; D001224:Aspartic Acid / Q000737:chemistry / Q000528:radiation effects*; D003653:Decarboxylation; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000737:chemistry; D005720:Gamma Rays; D008968:Molecular Conformation / Q000528:radiation effects
D005609:Free Radicals; D001224:Aspartic Acid; D001216:Asparagine