|
|
| Type |
Poster Presentation |
| Area |
Physical Chemistry |
| Room No. |
Grand Ballroom |
| Time |
10월 19일 (금요일) 11:00~12:30 |
| Code |
PHYS.P-222 |
| Subject |
The role of proton transfer in collision-induced dissociation of proton-bound hetero dimers of nucleic acid bases in the gas phase |
| Authors |
Jeongju Park, Sang Yun Han1,*
Department of Nanochemistry, Gachon University Global Campus, Korea
1Department of Nano Chemistry, Gachon University Global Campus, Korea
|
| Abstract |
We report the role of proton transfer in the proton-bound hetero dimers of C (cytosine), 1-MeC (1-methylcytosine), 5-MeC (5-methylcytosine) with G (guanine), and 1-MeG (1-methylguanine), 7-MeG (7-methylguanine), and 9-MeG (9-methylguanine) with 1-MeC. In the results, CID of proton-bound Hoogsteen base pair C:H+∙∙∙G, exhibited more abundant production of C:H+, the fragment protonated on the moiety with a smaller proton affinity, than G:H+. This appeared to contradict general prediction based on the kinetic method. However, further theoretical exploration of potential energy surfaces found that there can be facile proton transfers in the proton-bound Hoogsteen base pairs during the CID process, which makes the process accessible to an additional product state of O-protonated C for C:H+ fragments. The presence of an additional dissociation channel, which in other words corresponds to 2-fold degeneracy in the transition state leading to C:H+ fragments, effectively doubles the apparent reaction rate for production of C:H+. In this way, the process gives rise to the anomaly, the observed pronounced formation of C:H+ in the CID of the proton-bound Hoogsteen base pair, C:H+∙∙∙G. In this study, the effects of proton transfer that affect dissociation channels are extensively examined using various methylated guanines. |
| E-mail |
aifels@naver.com |
|
122nd General Meeting of the KCS