2PLX

Trypsin complexed to a synthetic peptide from Veronica hederifolia

2PLX の概要

• エントリーDOI: 10.2210/pdb2plx/pdb
• 関連するPDBエントリー: 2CMY
• 分子名称: Cationic trypsin, Peptide Inhibitor, CALCIUM ION, ... (6 entities in total)
• 機能のキーワード: helix-turn-helix, hydrolase
• 由来する生物種: Bos taurus (cattle); 詳細
• 細胞内の位置: Secreted, extracellular space: P00760
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 26855.32

構造登録者

Conners, R.,Brady, R.L. (登録日: 2007-04-20, 公開日: 2007-08-07, 最終更新日: 2024-10-09)

主引用文献

Conners, R.,Konarev, A.V.,Forsyth, J.,Lovegrove, A.,Marsh, J.,Joseph-Horne, T.,Shewry, P.,Brady, R.L.
An Unusual Helix-Turn-Helix Protease Inhibitory Motif in a Novel Trypsin Inhibitor from Seeds of Veronica (Veronica hederifolia L.)
J.Biol.Chem., 282:27760-27768, 2007

PubMed Abstract: The storage tissues of many plants contain protease inhibitors that are believed to play an important role in defending the plant from invasion by pests and pathogens. These proteinaceous inhibitor molecules belong to a number of structurally distinct families. We describe here the isolation, purification, initial inhibitory properties, and three-dimensional structure of a novel trypsin inhibitor from seeds of Veronica hederifolia (VhTI). The VhTI peptide inhibits trypsin with a submicromolar apparent K(i) and is expected to be specific for trypsin-like serine proteases. VhTI differs dramatically in structure from all previously described families of trypsin inhibitors, consisting of a helix-turn-helix motif, with the two alpha helices tightly associated by two disulfide bonds. Unusually, the crystallized complex is in the form of a stabilized acyl-enzyme intermediate with the scissile bond of the VhTI inhibitor cleaved and the resulting N-terminal portion of the inhibitor remaining attached to the trypsin catalytic serine 195 by an ester bond. A synthetic, truncated version of the VhTI peptide has also been produced and co-crystallized with trypsin but, surprisingly, is seen to be uncleaved and consequently forms a noncovalent complex with trypsin. The VhTI peptide shows that effective enzyme inhibitors can be constructed from simple helical motifs and provides a new scaffold on which to base the design of novel serine protease inhibitors.

PubMed: 17640870
DOI: 10.1074/jbc.M703871200

実験手法

X-RAY DIFFRACTION (1.56 Å)