ヒカリ サイクル ハンノウチュウ ニ オケル Photoactive Yellow Protein ノ ジカン ブンカイ コウゾウ ユラギ ノ ケンキュウ

京都大学0048新制・課程博士博士(理学)甲第13625号理博第3283号新制||理||1484(附属図書館)UT51-2008-C543京都大学大学院理学研究科化学専攻(主査)教授 寺嶋 正秀, 教授 竹腰 清乃理, 教授 中原 勝学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

Conformational Changes in the N-Terminal Region of Photoactive Yellow Protein: A Time-Resolved Diffusion Study

The kinetics of conformational change in the N-terminal region of photoactive yellow protein (PYP) was studied by the time-resolved diffusion measurement. The transient grating signal that represented the protein diffusion of the ground state and pB state depended on the observation time range. An analysis of the signal based on the time-dependent diffusion coefficient clearly showed that protein diffusion changed with a time constant of 170 μs, corresponding to the pR2 → pB′ transition. Since a previous diffusion study of N-terminal truncated PYPs had revealed that the change in the diffusion coefficient reflected the unfolding of the α-helices in the N-terminal region of PYP, the results indicate that this unfolding took place at the same rate as the pR2 → pB′ transition. This demonstrates that the response of the conformational change in the N-terminal region was quite fast, probably due to changes in a specific hydrogen-bonding network of this domain