2J3Q

Torpedo acetylcholinesterase complexed with fluorophore thioflavin T

2J3Q の概要

• エントリーDOI: 10.2210/pdb2j3q/pdb
• 関連するPDBエントリー: 1ACJ 1ACL 1AMN 1AX9 1CFJ 1DX6 1E3Q 1E66 1EA5 1EEA 1EVE 1FSS 1GPK 1GPN 1GQR 1GQS 1H22 1H23 1HBJ 1JGA 1JGB 1JJB 1OCE 1ODC 1QID 1QIE 1QIF 1QIG 1QIH 1QII 1QIJ 1QIK 1QIM 1QTI 1SOM 1U65 1UT6 1VOT 1VXO 1VXR 1W4L 1W6R 1W75 1W76 1ZGB 1ZGC 2ACE 2ACK 2C4H 2C58 2C5F 2C5G 2CEK 2CKM 2CMF 2DFP 2J3D 3ACE 4ACE
• 分子名称: ACETYLCHOLINESTERASE, 2-[4-(DIMETHYLAMINO)PHENYL]-6-HYDROXY-3-METHYL-1,3-BENZOTHIAZOL-3-IUM, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• 機能のキーワード: serine esterase, alternative splicing, lipoprotein, glycoprotein, torpedo ache, neurotransmitter degradation, anticancer prodrug cpt- 11, synapse, membrane, hydrolase, gpi-anchor
• 由来する生物種: TORPEDO CALIFORNICA (PACIFIC ELECTRIC RAY)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 62322.71

構造登録者

Harel, M.,Cusack, B.,Johnson, J.L.,Silman, I.,Sussman, J.L.,Rosenberry, T.L. (登録日: 2006-08-23, 公開日: 2007-09-04, 最終更新日: 2024-10-16)

主引用文献

Harel, M.,Sonoda, L.K.,Silman, I.,Sussman, J.L.,Rosenberry, T.L.
Crystal structure of thioflavin T bound to the peripheral site of Torpedo californica acetylcholinesterase reveals how thioflavin T acts as a sensitive fluorescent reporter of ligand binding to the acylation site.
J. Am. Chem. Soc., 130:7856-7861, 2008

PubMed Abstract: Acetylcholinesterase plays a key role in cholinergic synaptic transmission by hydrolyzing the neurotransmitter acetylcholine with one of the highest known catalytic rate constants. Hydrolysis occurs in a narrow and deep gorge that contains two sites of ligand binding: A peripheral site, or P-site, near the gorge entrance that contributes to catalytic efficiency both by transiently trapping substrate molecules as they enter the gorge and by allosterically accelerating the transfer of the substrate acyl group to a serine hydroxyl in an acylation site or A-site at the base of the gorge. Thioflavin T is a useful reporter of ligand interactions with the A-site. It binds specifically to the P-site with fluorescence that is enhanced approximately 1000-fold over that of unbound thioflavin T, and the enhanced fluorescence is quenched 1.5- to 4-fold when another ligand binds to the A-site in a ternary complex. To clarify the structural basis of this advantageous signal change, we here report the X-ray structure of the complex of thioflavin T with Torpedo californica acetylcholinesterase. The two aromatic rings in thioflavin T are coplanar and are packed snugly parallel to the aromatic side chains of Trp279, Tyr334, and Phe330. Overlays of this structure with the crystal structures of Torpedo californica acetylcholinesterase complexes with either edrophonium or m-( N, N, N-trimethylammonio)-2,2,2-trifluoroacetophenone, two small aromatic ligands that bind specifically to the A-site, indicate that the phenyl side chain of Phe330 must rotate to sterically accommodate both thioflavin T and the A-site ligand in the ternary complex. This rotation may allow some relaxation of the strict coplanarity of the aromatic rings in the bound thioflavin T and result in partial quenching of its fluorescence.

PubMed: 18512913
DOI: 10.1021/ja7109822

実験手法

X-RAY DIFFRACTION (2.8 Å)