A resonance Raman study on the structures of complexes of flavoprotein D-amino acid oxidase.
Resonance Raman (RR) spectra were obtained for the purple complexes of D-amino acid oxidase (DAO) with D-lysine or N-methylalanine. RR spectra of a complex of oxidized DAO with the oxidation product of D-lysine or D-proline were also measured. The isotope shifts of the observed bands of the purple complex with D-lysine upon 13C- or 15N-substitution of lysine indicate that the ligand is delta 1-piperideine-2-carboxylate. That the band at 1671 cm-1 for the purple intermediate with N-methylalanine shifts to 1666 cm-1 in D2O solution indicates that the imino acid, N-methyl-alpha-iminopropionate, has a protonated imino group. Many bands due to a ligand in the RR spectra of the complex of oxidized DAO with an oxidation product can be observed below 1000 cm-1, but no band for the purple complex is seen in this frequency region. The band associated with the CO2-symmetric stretching mode of the product, such as delta 1-piperideine-2-carboxylate or delta 1-pyrrolidine-2-carboxylate, complexed with the oxidized DAO shifts in D2O solution. This suggests that the product imino acid interacts with the enzyme through some proton(s).
Nishina
Y
Y
Miura
R
R
Tojo
H
H
Miyake
Y
Y
Watari
H
H
Shiga
K
K
D000409:Alanine / Q000031:analogs & derivatives; D000818:Animals; D001665:Binding Sites; D003605:D-Amino-Acid Oxidase; D007668:Kidney / Q000201:enzymology; D008239:Lysine; D010084:Oxidation-Reduction; D011392:Proline; D011522:Protons; D013059:Spectrum Analysis, Raman; D013552:Swine
D011522:Protons; C008408:N-methylalanine; D011392:Proline; D003605:D-Amino-Acid Oxidase; D008239:Lysine; D000409:Alanine