Dierickx P J
Instituut voor Hygiëne en Epidemiologie, Brussel.
Arch Int Physiol Biochim. 1988 Mar;96(1):1-5. doi: 10.3109/13813458809079619.
Glutathione transferase (GST) was purified from the microsomes of rat liver by glutathione affinity chromatography. The interaction of 2,4-dichlorophenoxyacetic acid (2,4-D) and 1,4-benzoquinone with microsomal GST was investigated and compared with cytosolic GST. The kinetic inhibition pattern of 1,4-benzoquinone towards microsomal GST was found to be different from that towards cytosolic GST. Microsomal GST purified by affinity chromatography was inhibited by 2,4-D in a non dose-dependent manner, while the crude microsomal GST was inhibited in a dose-dependent manner. This difference was shown to be induced by a reaction on the affinity column, and not by Triton X-100 (also shown to be a GST inhibitor), glutathione, or the elution buffer 0.2% Triton X-100 and 5 mM glutathione in 50 mM Tris-HCl, pH 9.6. The binding of microsomal GST to the affinity matrix caused a partial inactivation of the active site for 2,4-D interaction. The results show that the properties of soluble GST enzymes may not be extrapolated to the microsomal ones.
通过谷胱甘肽亲和层析从大鼠肝脏微粒体中纯化谷胱甘肽转移酶（GST）。研究了2,4-二氯苯氧乙酸（2,4-D）和1,4-苯醌与微粒体GST的相互作用，并与胞质GST进行比较。发现1,4-苯醌对微粒体GST的动力学抑制模式与对胞质GST的不同。通过亲和层析纯化的微粒体GST被2,4-D以非剂量依赖性方式抑制，而粗微粒体GST则以剂量依赖性方式被抑制。这种差异表明是由亲和柱上的反应诱导的，而不是由 Triton X-100（也被证明是一种GST抑制剂）、谷胱甘肽或洗脱缓冲液（50 mM Tris-HCl，pH 9.6中的0.2% Triton X-100和5 mM谷胱甘肽）诱导的。微粒体GST与亲和基质的结合导致了2,4-D相互作用活性位点的部分失活。结果表明，可溶性GST酶的性质可能不能外推到微粒体GST。
