...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >Purification and Characterization of a Specific 3-Deoxy-d-manno-Octulosonate 8-Phosphate Phosphatase from Escherichia coli B
【24h】

Purification and Characterization of a Specific 3-Deoxy-d-manno-Octulosonate 8-Phosphate Phosphatase from Escherichia coli B

机译：来自大肠杆菌B的特异性3-脱氧-D-甘露糖苷酸8-磷酸磷酸酶的纯化和表征

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A phosphatase specific for the hydrolysis of 3-deoxy-d-manno-octulosonate (KDO)-8-phosphate was purified approximately 400-fold from crude extracts of Escherichia coli B. The hydrolysis of KDO-8-phosphate to KDO and inorganic phosphate in crude extracts of E. coli B, grown in phosphate-containing minimal medium, could be accounted for by the enzymatic activity of this specific phosphatase. No other sugar phosphate tested was an alternate substrate or inhibitor of the purified enzyme. KDO-8-phosphate phosphatase was stimulated three- to fourfold by the addition of 1.0 mM Co+ or Mg2+ and to a lesser extent by 1.0 mM Ba2+, Zn2+, and Mn2+. The activity was inhibited by the addition of 1.0 mM ethylenediaminetetraacetic acid, Cu2+, Ca2+, Cd2+, Hg2+, and chloride ions (50% at 0.1 M). The pH optimum was determined to be 5.5 to 6.5 in both tris(hydroxymethyl)aminomethane-acetate and HEPES (N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid) buffer. This specific phosphatase had an isoelectric point of 4.7 to 4.8 and a molecular weight of 80,000 ± 6,000 as determined by molecular sieving and Ferguson analysis. The enzyme appeared to be composed of two identical subunits of 40,000 to 43,000 molecular weight. The apparent Km for KDO-8-phosphate was determined to be 5.8 ± 0.9 × 10?5 M in the presence of 1.0 mM Co2+, 9.1 ± 1 × 10?5 M in the presence of 1.0 mM Mg2+, and 1.0 ± 0.2 × 10?4 M in the absence of added Co2+ or Mg2+.
机译：用于水解3-脱氧-D- 甘露酸核酸（KDO）-8-磷酸盐的水解特异性的磷酸酶，从大肠杆菌的粗提取物中纯化约400倍。KDO-8-磷酸盐的水解在 E的粗提取物中的KDO和无机磷酸盐。在含磷酸盐的最小培养基中生长的Coli B可以通过该特定磷酸酶的酶活性来算是占据酶的。没有测试的糖磷酸盐是纯化酶的替代底物或抑制剂。通过加入1.0mM CO + / sop>或mg 2 + / sop>以较小程度为1.0mm ba ，通过添加1.0mm CO + / sup>刺激kdo-8-磷酸磷酸酶。 2 + ，Zn 2 + ，Mn 2 + 。通过加入1.0mM乙二胺四乙酸，Cu 2 + ，Cd 2 + ，Hg ，抑制活性。 2 + 和氯离子（50％在0.1μm）。在三（羟甲基）氨基甲烷 - 乙酸乙酯和HEPES（ N-Em> -2-羟乙基哌嗪 - n ' - 2-乙磺酸）中，测定pH值为5.5至6.5。缓冲。该特定的磷酸酶的等电点为4.7至4.8，分子量为80,000±6,000，如分子筛和弗格森分析所确定的。酶似乎由两个相同的亚基组成40,000至43,000分子量。 KDO-8-磷酸盐的表观 k m 在1.0 mm co的存在下测定为5.8±0.9×10 5 m 2 + ，9.1±1×10 α5 m在存在1.0 mm mg 2 + ，1.0±0.2×10 α4 m在没有添加的CO 2 + / sup>或mg 2 + 。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号