2F9P

Crystal Structure of the Recombinant Human Alpha I Tryptase Mutant D216G in Complex with Leupeptin

2F9P の概要

• エントリーDOI: 10.2210/pdb2f9p/pdb
• 関連するPDBエントリー: 2F9N 2F9O
• 関連するBIRD辞書のPRD_ID: PRD_000216
• 分子名称: Tryptase alpha-1, Leupeptin, alpha-L-fucopyranose-(1-3)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (6 entities in total)
• 機能のキーワード: serine proteinase, leupeptin, trypsin-like, difucosylation, hydrolase, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 113310.12

構造登録者

Rohr, K.B.,Selwood, T.,Marquardt, U.,Huber, R.,Schechter, N.M.,Bode, W.,Than, M.E. (登録日: 2005-12-06, 公開日: 2006-01-31, 最終更新日: 2024-11-06)

主引用文献

Rohr, K.B.,Selwood, T.,Marquardt, U.,Huber, R.,Schechter, N.M.,Bode, W.,Than, M.E.
X-ray Structures of Free and Leupeptin-complexed Human alpha I-Tryptase Mutants: Indication for an alpha to beta-Tryptase Transition
J.Mol.Biol., 357:195-209, 2005

PubMed Abstract: Tryptases alpha and beta are trypsin-like serine proteinases expressed in large amounts by mast cells. Beta-tryptase is a tetramer that has enzymatic activity, but requires heparin binding to maintain functional and structural stability, whereas alpha-tryptase has little, if any, enzymatic activity but is a stable tetramer in the absence of heparin. As shown previously, these differences can be mainly attributed to the different conformations of the 214-220 segment. Interestingly, the replacement of Asp216 by Gly, which is present in beta-tryptase, results in enzymatically active but less stable alpha-tryptase mutants. We have solved the crystal structures of both the single (D216G) and the double (K192Q/D216G) mutant forms of recombinant human alphaI-tryptase in complex with the peptide inhibitor leupeptin, as well as the structure of the non-inhibited single mutant. The inhibited mutants exhibited an open functional substrate binding site, while in the absence of an inhibitor, the open (beta-tryptase-like) and the closed (alpha-tryptase-like) conformations were present simultaneously. This shows that both forms are in a two-state equilibrium, which is influenced by the residues in the vicinity of the active site and by inhibitor/substrate binding. Novel insights regarding the observed stability differences as well as a potential proteolytic activity of wild-type alpha-tryptase, which may possess a cryptic active site, are discussed.

PubMed: 16414069
DOI: 10.1016/j.jmb.2005.12.037

実験手法

X-RAY DIFFRACTION (2.3 Å)