5ZAB

Crystal structure of cf3-aequorin

5ZAB の概要

• エントリーDOI: 10.2210/pdb5zab/pdb
• 分子名称: Aequorin-2, (2S)-8-benzyl-2-hydroperoxy-6-(4-hydroxyphenyl)-2-{[4-(trifluoromethyl)phenyl]methyl}imidazo[1,2-a]pyrazin-3(2H)-one (3 entities in total)
• 機能のキーワード: semi-synthetic aequorin, luminescent protein
• 由来する生物種: Aequorea victoria (Jellyfish)
• タンパク質・核酸の鎖数: 16
• 化学式量合計: 368825.25

構造登録者

Inouye, S.,Tomabechi, Y.,Sekine, S.I.,Shirouzu, M.,Hosoya, T. (登録日: 2018-02-07, 公開日: 2018-06-06, 最終更新日: 2023-11-22)

主引用文献

Inouye, S.,Tomabechi, Y.,Hosoya, T.,Sekine, S.I.,Shirouzu, M.
Slow luminescence kinetics of semi-synthetic aequorin: expression, purification and structure determination of cf3-aequorin.
J. Biochem., 164:247-255, 2018

PubMed Abstract: cf3-Aequorin is one of the semi-synthetic aequorins that was produced by replacing 2-peroxycoelenterazine (CTZ-OOH) in native aequorin with a 2-peroxycoelenterazine analog, and it was prepared using the C2-modified trifluoromethyl analog of coelenterazine (cf3-CTZ) and the histidine-tagged apoaequorin expressed in Escherichia coli cells. The purified cf3-aequorin showed a slow luminescence pattern with half-decay time of maximum intensities of luminescence of 5.0 s. This is much longer than that of 0.9 s for native aequorin, and its luminescence capacity was estimated to be 72.8% of that of native aequorin. The crystal structure of cf3-aequorin was determined at 2.15 Å resolution. The light source of 2-peroxytrifluoromethylcoelenterazine (cf3-CTZ-OOH) was stabilized by the hydrogen-bonding interactions at the C2-peroxy moiety and the p-hydroxy moiety at the C6-phenyl group. In native aequorin, three water molecules contribute to stabilizing CTZ-OOH through hydrogen bonds. However, cf3-aequorin only contained one water molecule, and the trifluoromethyl moiety at the C2-benzyl group of cf3-CTZ-OOH interacted with the protein by van der Waals interactions. The slow luminescence kinetics of cf3-aequorin could be explained by slow conformational changes due to the bulkiness of the trifluoromethyl group, which might hinder the smooth cleavage of hydrogen bonds at the C2-peroxy moiety after the binding of Ca2+ to cf3-aequorin.

PubMed: 29796619
DOI: 10.1093/jb/mvy049

実験手法

X-RAY DIFFRACTION (2.147 Å)