- 논문관련 분야의 소개, 동향, 전망을 설명
When excess light was irradiated on plant leaves, a lot of by-product can be generated such as singlet oxygen and reactive oxygen species (ROS) which are fatal to plant's survival. Therefore plants start to develop protection mechanism to avoid photodamage. The mechanism, so-called non-photochemical quenching (NPQ), dissipates the excess energy as a heat. Although the biological importance of this process was recognized well, the molecular details of this process were totally unknown. We have approached systematically from intact system to individual complexes in photosystem II including LHCII, antenna complexes, and CP minor complexes. We found the charge-transfer (CT) quenching in in vivo thylakoids and succeeded to explore CT quenching in minor complexes (CP29, CP26, and CP24). In this work, we focused on CP29 and tried to find which chlorophyll(s) triggers this CT quenching. We found that A5/B5 coupled chlorophylls and nearby zeaxanthin can generate CT quenching. We proved this chemical process from the biological scale (a few microns) to chemist's scale (a few nanometers). As the efficiency of photosynthesis rebukes the engineering tool to develop artificial solar cell, this photoprotection mechanism might help to design more stable photovoltaic devices.
[Figure 1. Structures of Photosystem II in Arabidopsis thaliana.]
Actually we finished this experiment more than one year ago and we were hesitating to submit this manuscript to Nature or Science. All of a sudden, other researchers' result about NPQ suggesting different mechanism has come up in Nature, so we decided to submit ours to Science. We didn't have to hesitate any more. In addition, their paper has made our results distinguishable and important.
2. 연구를 진행했던 소속기관 또는 연구소에 대해 소개 부탁 드립니다.
I'm working in Lawrence Berkeley National Laboratory (LBNL) and Department of Chemistry, at University of California, Berkeley (UC Berkeley). LBNL founded more than 75 years ago, and now a lot of world-class scientists are working in. And also Dept. of Chemistry at UC Berkeley is the top-class in Chemistry.
[Figure 2. Overview from LBNL]
3. 연구활동 하시면서 평소 느끼신 점 또는 자부심, 보람
My background is physical chemistry, but this field which I'm studying now is multidisciplinary including genetics, physiology, plant biology, biochemistry, and chemistry. My P.I. is physical chemist, just like me, and my major collaborators are Krishna K. Niyogi (Department of Plant and Plant Physiology, UC Berkeley) and Roberto Bassi (Department of Biology, University of Verona, Italy). Krishna is so-called Mr. NPQ, an biological expert in this field, and is always available in the same campus (UC Berkeley). Roberto is in Italy, but he try to bring his sample by himself to discuss and do experiment with me. My research condition was the best in this research. I'm so happy I'm involved in this good collaboration.
4. 이 분야로 진학하려는 후배들 또는 유학준비생들에게 도움이 되는 말씀을 해 주신다면?
When I was a graduate student, I couldn't expect any biological project. But now I cannot imagine my work without biologist and biological papers. Don't confine yourself as a specific technician. If we can ask about our research motivation rigorously often, we can make a progress wherever we are. Let's keep moving forward.
5. 연구활동과 관련된 앞으로의 계획이 있으시다면?
In near future, I plan to study more about biological analysis techniques, such as SDS-gel, Western Blots, HPLC, and Circular Dichoism etc. so I can analyze all kinds of protein complexes. Later I want to solve energy-related problems using chemical and biological methods.
6. 다른 하시고 싶은 이야기들....
I'd like to thank my coworkers including Thomas, Yuan-Chung, Krishna, Roberto, and my P.I., Graham. Without them, I couldn't accomplish this result. In addition, I appreciate my Ph. D. supervisors, Profs. Seong Keun Kim (School of Chem. at Seoul National Univ.) and Dongho Kim (Dept. of Chem. at Yonsei Univ.) for continuous supports.
|Received for article May 12, 2008