Carbonic anhydrase inhibitors:: The very weak inhibitors dithiothreitol, β-mercaptoethanol, tris(carboxyethyl) phosphine and threitol interfere with the binding of sulfonamides to isozymes II and IX
Carbonic anhydrase inhibitors:: The very weak inhibitors dithiothreitol, β-mercaptoethanol, tris(carboxyethyl) phosphine and threitol interfere with the binding of sulfonamides to isozymes II and IX
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DOI：
10.1016/j.bmcl.2008.02.008
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发表时间：
2008-03-15
影响因子：
2.7
通讯作者：
Supuran, Claudiu T.
中科院分区：
文献类型：
--
作者：
Innocenti, Alessio;Hilvo, Mika;Supuran, Claudiu T.
研究了二硫苏糖醇、2-巯基乙醇、三(羧乙基)膦（酶测定缓冲液中经常添加的还原剂）和苏糖醇对金属酶碳酸酐酶（CA、EC 4.2.1.1）的抑制作用。这些试剂是同工酶 CA II 和 CA IX 的非常弱的抑制剂，但出乎意料的是，强烈影响低纳摩尔磺酰胺抑制剂乙酰唑胺（5-乙酰氨基-1,3,4-噻二唑-2-磺酰胺）的结合。随着分析系统中这些药物浓度的增加，乙酰唑胺对所有研究的 CA 的亲和力均降低了几个数量级。 DTT 和类似的衍生物不应添加到用于监测 CA 活性/抑制的测定缓冲液中，因为它们通过可能涉及三元复合物形成的机制导致结合常数的低估。 (C) 2008 Elsevier Ltd. 保留所有权利。
The inhibition of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) with dithiothreitol, 2-mercaptoethanol, tris(carboxyethyl) phosphine (reducing agent frequently added to enzyme assay buffers) and threitol has been investigated. The agents were very weak inhibitors of isozymes CA II and CA IX, but unexpectedly, strongly influenced the binding of the low nano-molar sulfonamide inhibitor acetazolamide (5-acetamido-1,3,4-thiadiazole-2-sulfonamide). Acetazolamide affinity for all investigated CAs diminished orders of magnitude with increasing concentrations of these agents in the assay system. DTT and similar derivatives should not be added to the assay buffers used in monitoring CA activity/inhibition, as they lead to under-estimation of the binding constants, by a mechanism probably involving the formation of ternary complexes. (C) 2008 Elsevier Ltd. All rights reserved.