2HJB

Crystal structure of Alcaligenes faecalis AADH in complex with p-methoxybenzylamine

2HJB の概要

• エントリーDOI: 10.2210/pdb2hjb/pdb
• 関連するPDBエントリー: 2HJ4 2HJ7 2HKM 2HKR
• 分子名称: Aromatic amine dehydrogenase, 1-(4-METHOXYPHENYL)METHANAMINE, ... (4 entities in total)
• 機能のキーワード: p-substituted benzylamines; oxidoreductase, oxidoreductase
• 由来する生物種: Alcaligenes faecalis; 詳細
• 細胞内の位置: Periplasm : P84887 P84888
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 109340.40

構造登録者

Roujeinikova, A.,Leys, D. (登録日: 2006-06-30, 公開日: 2007-11-06, 最終更新日: 2025-03-26)

主引用文献

Hothi, P.,Roujeinikova, A.,Khadra, K.A.,Lee, M.,Cullis, P.,Leys, D.,Scrutton, N.S.
Isotope effects reveal that para-substituted benzylamines are poor reactivity probes of the quinoprotein mechanism for aromatic amine dehydrogenase.
Biochemistry, 46:9250-9259, 2007

PubMed Abstract: Structure-activity correlations have been employed previously in the mechanistic interpretation of TTQ-dependent amine dehydrogenases using a series of para-substituted benzylamines. However, by combining the use of kinetic isotope effects (KIEs) and crystallographic analysis, in conjunction with structure-reactivity correlation studies, we show that para-substituted benzylamines are poor reactivity probes for TTQ-dependent aromatic amine dehydrogenase (AADH). Stopped-flow kinetic studies of the reductive half-reaction, with para-substituted benzylamines and their dideuterated counterparts, demonstrate that C-H or C-D bond breakage is not fully rate limiting (KIEs approximately unity). Contrary to previous reports, Hammett plots exhibit a poor correlation of structure-reactivity data with electronic substituent effects for para-substituted benzylamines and phenylethylamines. Crystallographic studies of enzyme-substrate complexes reveal that the observed structure-reactivity correlations are not attributed to distinct binding modes for para-substituted benzylamines in the active site, although two binding sites for p-nitrobenzylamine are identified. We identify structural rearrangements, prior to the H-transfer step, which are likely to limit the rate of TTQ reduction by benzylamines. This work emphasizes (i) the need for caution when applying structure-activity correlations to enzyme-catalyzed reactions and (ii) the added benefit of using both isotope effects and structural analysis, in conjunction with structure-reactivity relationships, to study chemical steps in enzyme reaction cycles.

PubMed: 17636875
DOI: 10.1021/bi7007239

実験手法

X-RAY DIFFRACTION (1.85 Å)