1A5H

CATALYTIC DOMAIN OF HUMAN TWO-CHAIN TISSUE PLASMINOGEN ACTIVATOR COMPLEX OF A BIS-BENZAMIDINE

1A5H の概要

• エントリーDOI: 10.2210/pdb1a5h/pdb
• 分子名称: TISSUE PLASMINOGEN ACTIVATOR, 2,7-BIS-(4-AMIDINOBENZYLIDENE)-CYCLOHEPTAN-1-ONE, ... (4 entities in total)
• 機能のキーワード: trypsin like serine protease, fibrinolytic enzyme, hydrolase
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 58750.69

構造登録者

Renatus, M.,Bode, W.,Stubbs, M.T. (登録日: 1998-02-17, 公開日: 1999-04-20, 最終更新日: 2024-11-06)

主引用文献

Renatus, M.,Bode, W.,Huber, R.,Sturzebecher, J.,Prasa, D.,Fischer, S.,Kohnert, U.,Stubbs, M.T.
Structural mapping of the active site specificity determinants of human tissue-type plasminogen activator. Implications for the design of low molecular weight substrates and inhibitors.
J.Biol.Chem., 272:21713-21719, 1997

PubMed Abstract: The recent structure determination of the catalytic domain of tissue-type plasminogen activator (tPA) suggested residue Arg174 could play a role in P3/P4 substrate specificity. Six synthetic chromogenic tPA substrates of the type R-Xaa-Gly-Arg-p-nitroanilide, in which R is an N-terminal protection group, were synthesized to test this property. Although changing the residue Xaa (in its L or D form) at position P3 from the hydrophobic Phe to an acidic residue, Asp or Glu, gave no improvement in catalytic efficiency, comparative analysis of the substrates indicated a preference for an acidic substituent occupying the S3 site when the S4 site contains a hydrophobic or basic moiety. The 2.9 A structure determination of the catalytic domain of human tPA in complex with the bis-benzamidine inhibitor 2, 7-bis-(4-amidinobenzylidene)-cycloheptan-1-one reveals a three-site interaction, salt bridge formation of the proximal amidino group of the inhibitor with Asp189 in the primary specificity pocket, extensive hydrophobic surface burial, and a weak electrostatic interaction between the distal amidino group of the inhibitor and two carbonyl oxygens of the protein. The latter position was previously occupied by the guanidino group of Arg174, which swings out to form the western edge of the S3 pocket. These data suggest that the side chain of Arg174 is flexible, and does not play a major role in the S4 specificity of tPA. On the other hand, this residue would modulate S3 specificity, and may be exploited to fine tune the specificity and selectivity of tPA substrates and inhibitors.

PubMed: 9268299
DOI: 10.1074/jbc.272.35.21713

実験手法

X-RAY DIFFRACTION (2.9 Å)