Cloning, expression and biochemical characterization of one Epsilon-class (GST-3) and ten Delta-class (GST-1) glutathione S-transferases from Drosophila melanogaster, and identification of additional nine members of the Epsilon class
Cloning, expression and biochemical characterization of one Epsilon-class (GST-3) and ten Delta-class (GST-1) glutathione S-transferases from Drosophila melanogaster, and identification of additional nine members of the Epsilon class
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DOI：
10.1042/bj20021287
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发表时间：
2003-03-01
影响因子：
4.1
通讯作者：
Zimniak, P
中科院分区：
文献类型：
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作者：
Sawicki, R;Singh, SP;Zimniak, P
从果蝇，黑腹果蝇，10个成员的δ类谷胱甘肽S-转移酶（GST，以前表示为I类GST）和一个成员的ε类簇（以前GST-3）已被克隆，在大肠杆菌中表达，并已确定其催化性能。此外，通过生物信息学分析还确定了Eppery簇的另外9个成员，但没有进一步表征。在11种表达的酶中，7种接受脂质过氧化产物4-羟基壬烯醛作为底物，9种在1-氯-2，4-二硝基苯的谷胱甘肽结合中具有活性。由于酶活性蛋白包括DmGSTD 3和DmGSTD 7的基因产物，这些基因先前被认为是假基因，我们进一步研究了它们，并确定这两个基因在果蝇中转录。因此，我们目前的研究结果表明，DmGSTD 3和DmGSTD 7可能是功能基因。能够缀合4-羟基壬烯醛的昆虫GST的存在和多样性，在某些情况下其催化效率接近高度专门用于该功能的哺乳动物GST的催化效率，表明脂质过氧化产物的代谢是一种高度保守的生化途径，具有可能的解毒作用以及调节功能。
From the fruitfly, Drosophila melanogaster, ten members of the cluster of Delta-class glutathione S-transferases (GSTs; formerly denoted as Class I GSTs) and one member of the Epsilon-class cluster (formerly GST-3) have been cloned, expressed in Escherichia coli, and their catalytic properties have been determined. In addition, nine more members of the Epsilon cluster have been identified through bioinformatic analysis but not further characterized. Of the 11 expressed enzymes, seven accepted the lipid peroxidation product 4-hydroxynonenal as substrate, and nine were active in glutathione conjugation of 1-chloro-2,4-dinitrobenzene. Since the enzymically active proteins included the gene products of DmGSTD3 and DmGSTD7 which were previously deemed to be pseudogenes, we investigated them further and determined that both genes are transcribed in Drosophila. Thus our present results indicate that DmGSTD3 and DmGSTD7 are probably functional genes. The existence and multiplicity of insect GSTs capable of conjugating 4-hydroxynonenal, in some cases with catalytic efficiencies approaching those of mammalian GSTs highly specialized for this function, indicates that metabolism of products of lipid peroxidation is a highly conserved biochemical pathway with probable detoxification as well as regulatory functions.