1QIX

Porcine pancreatic elastase complexed with human beta-casomorphin-7

1QIX の概要

• エントリーDOI: 10.2210/pdb1qix/pdb
• 関連するPDBエントリー: 3EST
• 分子名称: BETA-CASOMORPHIN-7, ELASTASE, CALCIUM ION, ... (5 entities in total)
• 機能のキーワード: serine proteinase, hydrolase (serine proteinase)
• 由来する生物種: SUS SCROFA (PIG); 詳細
• 細胞内の位置: Secreted: P00772
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 26928.17

構造登録者

Wilmouth, R.C.,Clifton, I.J.,Hajdu, J.,Schofield, C.J. (登録日: 1999-06-18, 公開日: 1999-12-14, 最終更新日: 2024-11-13)

主引用文献

Wilmouth, R.C.,Clifton, I.J.,Robinson, C.V.,Roach, P.L.,Aplin, R.T.,Westwood, N.J.,Hajdu, J.,Schofield, C.J.
Structure of a Specific Acyl-Enzyme Complex Formed between Beta-Casomorphin-7 and Porcine Pancreatic Elastase
Nat.Struct.Biol., 4:456-, 1997

PubMed Abstract: Mass spectrometric screening reveals that an unmodified natural heptapeptide--human beta-casomorphin-7, an internal sequence of human beta-casein that possesses opioid-like activity--reacts with porcine pancreatic elastase to form an unusually stable acyl-enzyme complex at low pH. X-ray crystallographic analysis (to 1.9 A resolution) at pH 5 shows continuous electron density linking the C-terminal isoleucine of beta-casomorphin-7 to Ser 195 through an ester bond. The structure reveals a well defined water molecule (Wat 317), equidistant between the carbon of the ester carbonyl and N epsilon 2 of His 57. Deprotonation of Wat 317 will produce a hydroxide ion positioned to attack the ester carbonyl through the favoured Bürgi-Dunitz trajectory.

PubMed: 9187653
DOI: 10.1038/NSB0697-456

実験手法

X-RAY DIFFRACTION (1.9 Å)