1ETT

REFINED 2.3 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF BOVINE THROMBIN COMPLEXES FORMED WITH THE BENZAMIDINE AND ARGININE-BASED THROMBIN INHIBITORS NAPAP, 4-TAPAP AND MQPA: A STARTING POINT FOR IMPROVING ANTITHROMBOTICS

1ETT の概要

• エントリーDOI: 10.2210/pdb1ett/pdb
• 関連するPDBエントリー: 1ETR 1ETS
• 分子名称: EPSILON-THROMBIN, 4-[(2S)-2-{[(4-methylphenyl)sulfonyl]amino}-3-oxo-3-(piperidin-1-yl)propyl]benzene-1-carboximidamide, ... (4 entities in total)
• 機能のキーワード: serine proteinase, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• 由来する生物種: Bos taurus (cow); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 35936.21

構造登録者

Bode, W.,Brandstetter, H. (登録日: 1992-07-06, 公開日: 1994-01-31, 最終更新日: 2024-11-20)

主引用文献

Brandstetter, H.,Turk, D.,Hoeffken, H.W.,Grosse, D.,Sturzebecher, J.,Martin, P.D.,Edwards, B.F.,Bode, W.
Refined 2.3 A X-ray crystal structure of bovine thrombin complexes formed with the benzamidine and arginine-based thrombin inhibitors NAPAP, 4-TAPAP and MQPA. A starting point for improving antithrombotics.
J.Mol.Biol., 226:1085-1099, 1992

PubMed Abstract: Well-diffracting crystals of bovine epsilon-thrombin in complex with several "non-peptidic" benzamidine and arginine-based thrombin inhibitors have been obtained by co-crystallization. The 2.3 A crystal structures of three complexes formed either with NAPAP, 4-TAPAP, or MQPA, were solved by Patterson search methods and refined to crystallographic R-values of 0.167 to 0.178. The active-site environment of thrombin is only slightly affected by binding of the different inhibitors; in particular, the exposed "60-insertion loop" essentially maintains its typical projecting structure. The D-stereoisomer of NAPAP and the L-stereoisomer of MQPA bind to thrombin with very similar conformations, as previously inferred from their binding to bovine trypsin; the arginine side-chain of the latter inserts into the specificity pocket in a "non-canonical" manner. The L-stereoisomer of 4-TAPAP, whose binding geometry towards trypsin was only poorly defined, is bound to the thrombin active-site in a compact conformation. In contrast to NAPAP, the distal p-amidino/guanidino groups of 4-TAPAP and MQPA do not interact with the carboxylate group of Asp189 in the thrombin specificity pocket in a "symmetrical" twin N-twin O manner, but through "lateral" single N-twin O contacts; in contrast to the p-amidino group of 4-TAPAP, however, the guanidyl group of MQPA packs favourably in the pocket due to an elaborate hydrogen bond network, which includes two entrapped water molecules. These thrombin structures confirm previous conclusions of the important role of the intermolecular hydrogen bonds formed with Gly216, and of the good sterical fit of the terminal bulky hydrophobic inhibitor groups with the hydrophobic aryl binding site and the S2-cavity, respectively, for tight thrombin active site binding of these non-peptidic inhibitors. These accurate crystal structures are presumed to be excellent starting points for the design and the elaboration of improved antithrombotics.

PubMed: 1518046
DOI: 10.1016/0022-2836(92)91054-S

実験手法

X-RAY DIFFRACTION (2.5 Å)