3HG2

Human alpha-galactosidase catalytic mechanism 1. Empty active site

3HG2 の概要

• エントリーDOI: 10.2210/pdb3hg2/pdb
• 関連するPDBエントリー: 1R46 1R47 3HG3 3HG4 3HG5
• 分子名称: Alpha-galactosidase A, alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranose, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total)
• 機能のキーワード: glycoprotein, carbohydrate-binding protein, glycosidase, lysosomal enzyme, (beta/alpha)8 barrel, disease mutation, disulfide bond, hydrolase, lysosome
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 93641.64

構造登録者

Guce, A.I.,Clark, N.E.,Garman, S.C. (登録日: 2009-05-13, 公開日: 2009-11-24, 最終更新日: 2024-10-09)

主引用文献

Guce, A.I.,Clark, N.E.,Salgado, E.N.,Ivanen, D.R.,Kulminskaya, A.A.,Brumer, H.,Garman, S.C.
Catalytic mechanism of human alpha-galactosidase.
J.Biol.Chem., 285:3625-3632, 2010

PubMed Abstract: The enzyme alpha-galactosidase (alpha-GAL, also known as alpha-GAL A; E.C. 3.2.1.22) is responsible for the breakdown of alpha-galactosides in the lysosome. Defects in human alpha-GAL lead to the development of Fabry disease, a lysosomal storage disorder characterized by the buildup of alpha-galactosylated substrates in the tissues. alpha-GAL is an active target of clinical research: there are currently two treatment options for Fabry disease, recombinant enzyme replacement therapy (approved in the United States in 2003) and pharmacological chaperone therapy (currently in clinical trials). Previously, we have reported the structure of human alpha-GAL, which revealed the overall structure of the enzyme and established the locations of hundreds of mutations that lead to the development of Fabry disease. Here, we describe the catalytic mechanism of the enzyme derived from x-ray crystal structures of each of the four stages of the double displacement reaction mechanism. Use of a difluoro-alpha-galactopyranoside allowed trapping of a covalent intermediate. The ensemble of structures reveals distortion of the ligand into a (1)S(3) skew (or twist) boat conformation in the middle of the reaction cycle. The high resolution structures of each step in the catalytic cycle will allow for improved drug design efforts on alpha-GAL and other glycoside hydrolase family 27 enzymes by developing ligands that specifically target different states of the catalytic cycle. Additionally, the structures revealed a second ligand-binding site suitable for targeting by novel pharmacological chaperones.

PubMed: 19940122
DOI: 10.1074/jbc.M109.060145

実験手法

X-RAY DIFFRACTION (2.3 Å)