谷胱甘肽转移酶与 Cibacron Blue 3GA 及其片段的相互作用。

The Interaction of Glutathione Transferase with Cibacron Blue 3GA and its Fragments.

机构信息

Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855-Athens, Greece.

Laboratory of Genetics, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855-Athens, Greece.

出版信息

Med Chem. 2021;17(4):332-343. doi: 10.2174/1573406416666200403074742.

DOI:10.2174/1573406416666200403074742

PMID:32242785

Abstract

BACKGROUND

The 26kDa glutathione transferase (GST, EC 2.5.1.18) from Schistosoma japonicum (SjGST) is recognized as the major detoxification enzyme of S. japonicum, a pathogenic helminth causing schistosomiasis.

OBJECTIVE

In the present study, the interaction of the chlorotriazine dye Cibacron blue 3GA (CB3GA) and its structural analogues with SjGST was investigated. The work aimed to shed light on the non-substrate ligand-binding properties of the enzyme.

METHODS

Kinetic inhibition analysis, affinity labelling experiments and molecular modelling studies were employed.

RESULTS

The results showed that CB3GA is a potent inhibitor (IC 0.057 ± 0.003 μM) towards SjGST. The enzyme was specifically and irreversibly inactivated by the dichlorotriazine-analogue of CB3GA (IC 0.190 ± 0.024 μM), following a biphasic pseudo-first-order saturation kinetics with approximately 1 mol of inhibitor per mol of the dimeric enzyme being incorporated. All other monochlorotriazine analogues behave as reversible inhibitors with lower inhibition potency (IC 5.2-82.3 μM). Kinetic inhibition studies, together with molecular modelling and molecular dynamics simulations, established that the CB3GA binding site overlaps both the G- and H-sites. Both hydrophobic/ polar interactions, as well as steric effects, have decisive roles in determining the inhibitory strength of CB3GA and its analogues.

CONCLUSION

The results of the present study might be useful in future drug design and development efforts towards SjGST.

摘要

背景

来自日本血吸虫（SjGST）的 26kDa 谷胱甘肽转移酶（GST，EC 2.5.1.18）被认为是日本血吸虫的主要解毒酶，日本血吸虫是一种引起血吸虫病的致病寄生虫。

目的

本研究旨在探讨氯三嗪染料 Cibacron blue 3GA（CB3GA）及其结构类似物与 SjGST 的相互作用。旨在阐明该酶的非底物配体结合特性。

方法

采用动力学抑制分析、亲和标记实验和分子建模研究。

结果

结果表明，CB3GA 是 SjGST 的有效抑制剂（IC 0.057±0.003 μM）。该酶被 CB3GA 的二氯三嗪类似物特异性和不可逆地失活（IC 0.190±0.024 μM），遵循双相拟一级饱和动力学，约 1 摩尔抑制剂与二聚酶的摩尔数结合。所有其他单氯三嗪类似物均表现为可逆抑制剂，抑制能力较低（IC 5.2-82.3 μM）。动力学抑制研究，以及分子建模和分子动力学模拟，确立了 CB3GA 的结合位点与 G-和 H-位点重叠。疏水性/极性相互作用以及空间位阻效应对确定 CB3GA 及其类似物的抑制强度都具有决定性作用。