Your browser doesn't support javascript.
loading
Proton Transfer Accompanied by the Oxidation of Adenosine.
Choi, Jungkweon; Tojo, Sachiko; Ahn, Doo-Sik; Fujitsuka, Mamoru; Miyamoto, Shunichi; Kobayashi, Kazuo; Ihee, Hyotcherl; Majima, Tetsuro.
Afiliación
  • Choi J; Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 305-701, Republic of Korea.
  • Tojo S; Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea.
  • Ahn DS; The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan.
  • Fujitsuka M; Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 305-701, Republic of Korea.
  • Miyamoto S; Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, Republic of Korea.
  • Kobayashi K; The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan.
  • Ihee H; The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan.
  • Majima T; The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan.
Chemistry ; 25(32): 7711-7718, 2019 Jun 07.
Article en En | MEDLINE | ID: mdl-30957282
Despite numerous experimental and theoretical studies, the proton transfer accompanying the oxidation of 2'-deoxyadenosine 5'-monophosphate 2'-deoxyadenosine 5'-monophosphate (5'-dAMP, A) is still under debate. To address this issue, we have investigated the oxidation of A in acidic and neutral solutions by using transient absorption (TA) and time-resolved resonance Raman (TR3 ) spectroscopic methods in combination with pulse radiolysis. The steady-state Raman signal of A was significantly affected by the solution pH, but not by the concentration of adenosine (2-50 mm). More specifically, the A in acidic and neutral solutions exists in its protonated (AH+ (N1+H+ )) and neutral (A) forms, respectively. On the one hand, the TA spectral changes observed at neutral pH revealed that the radical cation (A.+ ) generated by pulse radiolysis is rapidly converted into A. (N6-H) through the loss of an imino proton from N6. In contrast, at acidic pH (<4), AH.2+ (N1+H+ ) generated by pulse radiolysis of AH+ (N1+H+ ) does not undergo the deprotonation process owing to the pKa value of AH.2+ (N1+H+ ), which is higher than the solution pH. Furthermore, the results presented in this study have demonstrated that A, AH+ (N1+H+ ), and their radical species exist as monomers in the concentration range of 2-50 mm. Compared with the Raman bands of AH+ (N1+H+ ), the TR3 bands of AH.2+ (N1+H+ ) are significantly down-shifted, indicating a decrease in the bond order of the pyrimidine and imidazole rings due to the resonance structure of AH.2+ (N1+H+ ). Meanwhile, A. (N6-H) does not show a Raman band corresponding to the pyrimidine+NH2 scissoring vibration due to diprotonation at the N6 position. These results support the final products generated by the oxidation of adenosine in acidic and neutral solutions being AH.2+ (N1+H+ ) and A. (N6-H), respectively.
Palabras clave

Texto completo: 1 Banco de datos: MEDLINE Idioma: En Revista: Chemistry Asunto de la revista: QUIMICA Año: 2019 Tipo del documento: Article

Texto completo: 1 Banco de datos: MEDLINE Idioma: En Revista: Chemistry Asunto de la revista: QUIMICA Año: 2019 Tipo del documento: Article