Investigations of the esterase, phosphatase, and sulfatase activities of the cytosolic mammalian carbonic anhydrase isoforms I, II, and XIII with 4-nitrophenyl esters as substrates

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• 作者：Alessio Innocenti ; Andrea Scozzafava ; Seppo Parkkila ; Luca Puccetti ; Giuseppina De Simone ; Claudiu T. Supuran
• 关键词：Carbonic anhydrase ; Cytosolic isozyme ; Esterase ; Phosphatase ; Sulfatase ; 4-Nitrophenyl esters
• 刊名：Bioorganic and Medicinal Chemistry Letters
• 出版年：2008
• 期刊代码：10_0960894x
• 类别：ch
• 出版时间：1 April 2008
• 卷：18
• 期：7
• 页码：2267-2271
• 文件大小：141 K

摘要

The esterase, phosphatase, and sulfatase activities of carbonic anhydrase (CA, EC 4.2.1.1) isozymes, CA I, II, and XIII with 4-nitrophenyl esters as substrates was investigated. These enzymes show esterase activity with 4-nitrophenyl acetate as substrate, with second order rate constants in the range of 753–7706 M⁻¹ s⁻¹, being less effective as phosphatases (k_cat/K_M in the range of 14.89–1374.40 M⁻¹ s⁻¹) and totally ineffective sulfatases. The esterase/phosphatase activities were inhibited by sulfonamide CA inhibitors, proving that the zinc-hydroxide mechanism responsible for the CO₂ hydrase activities of CAs is also responsible for their esterase/phosphatase activity. CA XIII was the most effective esterase and phosphatase. CA XIII might catalyze other physiological reactions than CO₂ hydration, based on its relevant phosphatase activity.