最近の研究から
Mn（II）イオンの結合によって誘起される結晶相ADPリボース加水分解酵素反応の観察
2016 年 58 巻 4 号 p. 186-192
詳細
2016 年 58 巻 4 号 p. 186-192
ADP-Ribose pyrophosphatase (ADPRase) reaction was observed in crystalline-state at atomic resolutions around 1 Å. ADPRase achieves the general acid-base catalysis in the presence of divalent metal cations. Crystals of ADPRase alone, ADPRase-ADPR binary (ES-state) complex were prepared, and reaction intermediates were captured by the cryo-trapping after the soaking of MnCl2 into ES-state crystals. Just after two metal binding sites were successively occupied along with the soaking time, ADPR was hydrolyzed and reaction products were released, indicating the completion of the crystalline-state reaction. The key structures of ADPRase-ADPR-two Mn2+ ions complex revealed the various enzymatic phenomena including electrostatic, proximity and orientation effects and preferential binding for the transition states. The details of the metal assisting mechanism and the general base catalysis have been discussed.
