Expression and localization of α- and β-carbonic anhydrase in Helicobacter pylori
Expression and localization of α- and β-carbonic anhydrase in Helicobacter pylori
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DOI：
10.1016/s1570-9639(02)00467-3
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发表时间：
2002-12-16
影响因子：
3.2
通讯作者：
Lindskog, S
中科院分区：
文献类型：
--
作者：
Chirica, LC;Petersson, C;Lindskog, S
幽门螺杆菌是消化性溃疡疾病的病原体，表达两种不同形式的含锌酶碳酸酐酶（CA）（α和β），催化CO2的可逆水合作用。据推测，H. pylori的存在暗示了这种酶在细菌生理学中的重要作用。在本文中，CA的表达已经分析了在三个不同的菌株的细菌，26695，J99和17.1，似乎是独立的CO2浓度在调查范围内（0.1 - 10%）。培养基中存在有效且高度特异性的CA抑制剂乙酰唑胺，在给定的磺胺浓度下似乎不会抑制细菌生长。此外，通过免疫阴性染色分析α-CA的定位和分布，而SDS消化的冷冻断裂免疫金标记用于酶的β-形式。后一种方法具有允许评估蛋白定位于不同细胞隔室和膜结构的优点。所得的电子显微镜图像表明β-CA定位于胞质溶胶中，位于内膜的胞质侧和面向周质空间的外膜上。发现α-酶附着在细菌的表面。(C)2002 Elsevier Science B.V.保留所有权利。
Helicobacter pylori, the causative agent of peptic ulcer disease, expresses two different forms of the zinc-containing enzyme carbonic anhydrase (CA) (alpha and beta), catalyzing the reversible hydration Of CO2. Presumably, the high CO2 requirement of H. pylori implies an important role for this enzyme in the bacterial physiology. In this paper, expression of the CAs has been analyzed in three different strains of the bacterium, 26695, J99 and 17.1, and appears to be independent Of CO2 concentration in the investigated range (0.1-10%). Presence of the potent and highly specific CA inhibitor, acetazolamide, in the medium does not seem to inhibit bacterial growth at the given sulfonamide concentration. Moreover, the localization and distribution of the alpha-CA was analyzed by immunonegative staining, while SDS-digested freeze-fracture immunogold labelling was used for the beta-form of the enzyme. The latter method has the advantage of allowing assessment of protein localization to distinct cell compartments and membrane structures. The resulting electron microscopy images indicate a localization of the beta-CA in the cytosol, on the cytosolic side of the inner membrane and on the outer membrane facing the periplasmic space. The alpha-enzyme was found attached to the surface of the bacterium. (C) 2002 Elsevier Science B.V. All rights reserved.