2C76

Functional Role of the Aromatic Cage in Human Monoamine Oxidase B: Structures and Catalytic Properties of Tyr435 Mutant Proteins

2C76 の概要

• エントリーDOI: 10.2210/pdb2c76/pdb
• 関連するPDBエントリー: 1GOS 1H8R 1OJ9 1OJA 1OJB 1OJC 1OJD 1S2Q 1S2Y 1S3B 1S3E 2BK3 2BK4 2BK5 2BYB 2C64 2C65 2C66 2C67 2C70 2C72 2C73 2C75
• 分子名称: AMINE OXIDASE (FLAVIN-CONTAINING) B, FLAVIN-ADENINE DINUCLEOTIDE, N-PROPARGYL-1(S)-AMINOINDAN, ... (4 entities in total)
• 機能のキーワード: oxidoreductase, enantioselectivity, fad, flavin, flavoprotein, human monoamine oxidase, inhibitor binding, mitochondrion, rasagiline, transmembrane, parkinson, acetylation
• 由来する生物種: HOMO SAPIENS (HUMAN)
• 細胞内の位置: Mitochondrion outer membrane; Single-pass type IV membrane protein; Cytoplasmic side: P27338
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 119635.12

構造登録者

Li, M.,Binda, C.,Mattevi, A.,Edmondson, D.E. (登録日: 2005-11-17, 公開日: 2006-04-19, 最終更新日: 2024-10-23)

主引用文献

Li, M.,Binda, C.,Mattevi, A.,Edmondson, D.E.
Functional Role of the Aromatic Cage in Human Monoamine Oxidase B: Structures and Catalytic Properties of Tyr435 Mutant Proteins
Biochemistry, 45:4775-, 2006

PubMed Abstract: Current structural results of several flavin-dependent amine oxidizing enzymes including human monoamine oxidases A and B (MAO A and MAO B) show aromatic amino acid residues oriented approximately perpendicular to the flavin ring, suggesting a functional role in catalysis. In the case of human MAO B, two tyrosyl residues (Y398 and Y435) are found in the substrate binding site on the re face of the covalent flavin ring [Binda et al. (2002) J. Biol. Chem. 277, 23973-23976]. To probe the functional significance of this structure, Tyr435 in MAO B was mutated with the amino acids Phe, His, Leu, or Trp, the mutant proteins expressed in Pichia pastoris, and purified to homogeneity. Each mutant protein contains covalent FAD and exhibits a high level of catalytic functionality. No major alterations in active site structures are detected on comparison of their respective crystal structures with that of WT enzyme. The relative k(cat)/K(m) values for each mutant enzyme show Y435 > Y435F = Y435L = Y435H > Y435W. A similar behavior is also observed with the membrane-bound forms of MAO A and MAO B (MAO A Y444 mutant enzymes are found to be unstable on membrane extraction). p-Nitrobenzylamine is found to be a poor substrate while p-nitrophenethylamine is found to be a good substrate for all WT and mutant forms of MAO B. Analysis of these kinetic and structural data suggests the function of the "aromatic cage" in MAO to include a steric role in substrate binding and access to the flavin coenzyme and to increase the nucleophilicity of the substrate amine moiety. These results are consistent with a proposed polar nucleophilic mechanism for catalytic amine oxidation.

PubMed: 16605246
DOI: 10.1021/BI051847G

実験手法

X-RAY DIFFRACTION (1.7 Å)