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生命科學實驗. Enzymatic analysis of GST-Leu2/ leu2. Glutathione-S- transferases (GSTs)
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生命科學實驗 Enzymatic analysis of GST-Leu2/ leu2
Glutathione-S-transferases (GSTs) are a group of enzymes that are important in the detoxication of many different xenobiotics in mammals. The enzymes protect cells against toxicants by conjugating the thiol group of the glutathione to electrophilicxenobiotics, and thereby defend cells against the mutagenic, carcinogenic, and toxic effects of the compounds.
1-chloro-2,4-dinitrobenzene (CDNB) GST GSH + CDNB → GS-DNB conjugate + HCl A 340nm
A340 (Time 2) - A340 (Time 1) (△A340)/min = Time 2 (min.) - Time 1 (min.)
GST specific activity: (△A340)/min × V (ml) × dilution = umol/ml/min εmM× V enzyme (ml) εmM(mM-1cm-1): the extinction coefficient for CDNB conjugate at 340 nm, for test in 1 ml cuvette = 9.6 mM-1 (path length -1 cm). V : the reaction volume, for test in 1 ml cuvette = 1 ml V enzyme: the volume of the enzyme sample tested = 0.01 ml