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首页> 外文期刊>Journal of bacteriology >Cytochemical Localization of Certain Phosphatases in Escherichia coli
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Cytochemical Localization of Certain Phosphatases in Escherichia coli

机译：大肠杆菌中某些磷酸酶的细胞化学定位

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Cytochemical studies of Escherichia coli at the light and electron microscopic levels have revealed alkaline phosphatase, hexose monophosphatase, and cyclic phosphodiesterase reaction products in the periplasmic space and at the cell surface. In preparations for both light and electron microscopy, reaction product filled polar caplike enlargements of the periplasmic space, such as those described in plasmolyzed cells, indicating significant terminal concentrations of these enzymes; dense substance was often seen within these polar caps in morphological specimens. Staining of the bacterial surface was commonly encountered, but could represent artifactual accumulation of precipitate along the cell wall. Alkaline phosphatase was demonstrated with several substrates (ethanolamine phosphate, glycerophosphate, p-nitrophenylphosphate, and glucose-6-phosphate) over a wide pH range in a bacterial strain (C-90) known to be constitutive for this enzyme, whereas strains deficient in this enzyme (U-7, repressed K-37), showed no activity with these substrates. Hexose monophosphatase and cyclic phosphodiesterase activities were characterized by reaction-product deposition with specific substrates at acid or neutral, but not at alkaline, pH in strains of E. coli lacking alkaline phosphatase (U-7 and repressed K-37). Fixation in Formalin or the use of calcium as a capture reagent seemed to interfere with periplasmic staining in cells prepared for electron microscopy. Formalin fixation had little effect on biochemical assays of the phosphatase activity of intact cells in suspension, but partially reduced the activity evident in sonically treated extracts or in suspensions of dispersed cryostat sections. Glutaraldehyde treatment impaired enzyme activity more drastically.
机译：在光学和电子显微镜下对大肠杆菌的细胞化学研究表明，在周质空间和细胞表面碱性磷酸酶，己糖单磷酸酶和环状磷酸二酯酶反应产物。在光镜和电子显微镜的准备工作中，反应产物充满了周质空间的极帽状增大，例如在溶浆细胞中描述的那些，表明这些酶的显着末端浓度。在形态标本中的这些极帽内经常看到致密物质。通常会遇到细菌表面的染色，但可能代表沿细胞壁的沉淀物的人为累积。碱性磷酸酶在细菌菌株（C）中在很宽的 p H范围内被证明具有多种底物（乙醇胺磷酸酯，甘油磷酸酯， p -硝基苯基磷酸酯和葡萄糖-6-磷酸酯） -90）已知是该酶的组成成分，而缺乏该酶的菌株（U-7，受阻的K-37）对这些底物没有活性。己糖单磷酸酶和环状磷酸二酯酶活性的特征是在 E菌株中，在特定的底物上，在酸性或中性下而不在碱性的 p H下反应产物沉积。缺乏碱性磷酸酶（U-7和抑制的K-37）的大肠杆菌。用福尔马林固定或使用钙作为捕获剂似乎干扰了准备用于电子显微镜的细胞的周质染色。福尔马林固定对悬浮液中完整细胞磷酸酶活性的生化分析影响很小，但在超声处理过的提取物或低温恒温器切片悬浮液中明显降低了活性。戊二醛处理更严重地损害了酶的活性。

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