• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文OA文献 >Characterization of anaerobic sulfite reduction by Salmonella typhimurium and purification of the anaerobically induced sulfite reductase.
【2h】

Characterization of anaerobic sulfite reduction by Salmonella typhimurium and purification of the anaerobically induced sulfite reductase.

机译：鼠伤寒沙门氏菌还原厌氧亚硫酸盐的特性和厌氧诱导的亚硫酸盐还原酶的纯化。

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Mutants of Salmonella typhimurium that lack the biosynthetic sulfite reductase (cysI and cysJ mutants) retain the ability to reduce sulfite for growth under anaerobic conditions (E. L. Barrett and G. W. Chang, J. Gen. Microbiol., 115:513-516, 1979). Here we report studies of sulfite reduction by a cysI mutant of S. typhimurium and purification of the associated anaerobic sulfite reductase. Sulfite reduction for anaerobic growth did not require a reducing atmosphere but was prevented by an argon atmosphere contaminated with air (less than 0.33%). It was also prevented by the presence of 0.1 mM nitrate, which argues against a strictly biosynthetic role for anaerobic sulfite reduction. Anaerobic growth in liquid minimal medium, but not on agar, was found to require additions of trace amounts (10(-7)M) of cysteine. Spontaneous mutants that grew under the argon contaminated with air also lost the requirement for 10(-7)M cysteine for anaerobic growth in liquid. A role for sulfite reduction in anaerobic energy generation was contraindicated by the findings that sulfite reduction did not improve cell yields, and anaerobic sulfite reductase activity was greatest during the stationary phase of growth. Sulfite reductase was purified from the cytoplasmic fraction of the anaerobically grown cysI mutant and was purified 190-fold. The most effective donor in crude extracts was NADH. NADPH and methyl viologen were, respectively, 40 and 30% as effective as NADH. Oxygen reversibly inhibited the enzyme. Two high-molecular-weight proteins separated by gel filtration (Mr 360,000 and 490,000, respectively) were required for maximal activity with NADH. Indirect evidence, including in vitro complementation experiments with a cysG mutant extract, suggested that the 360,000-Mr component contains siroheme and is the terminal reductase. This component was further purified to near homogeneity and was found to consist of a single subunit of molecular weight 67,500. The anaerobic sulfite reductase showed some resemblance to the biosynthetic sulfite reductase, but apparently it has a unique, as yet unidentified function.
机译：缺乏生物合成亚硫酸盐还原酶的鼠伤寒沙门氏菌突变体（cysI和cysJ突变体）保留了在无氧条件下还原亚硫酸盐生长的能力（E. L. Barrett和G.W. Chang，J.Gen.Microbiol。，115：513-516，1979）。在这里，我们报告了鼠伤寒沙门氏菌的cysI突变体对亚硫酸盐还原的研究以及相关厌氧亚硫酸盐还原酶的纯化。用于厌氧生长的亚硫酸盐还原不需要还原性气氛，但是被被空气污染的氩气气氛（小于0.33％）阻止了。 0.1 mM硝酸盐的存在也可以防止这种情况，这反对严格的生物合成作用来减少厌氧亚硫酸盐。发现在液体基本培养基中而不是在琼脂上的厌氧生长需要添加痕量（10（-7）M）的半胱氨酸。在被空气污染的氩气下生长的自发突变体也失去了在液体中厌氧生长所需的10（-7）M半胱氨酸的需求。发现亚硫酸盐还原并不能提高细胞产量，并且在生长的稳定期厌氧亚硫酸盐还原酶活性最大的发现禁忌了亚硫酸盐还原在厌氧能量产生中的作用。从厌氧生长的cysI突变体的细胞质部分纯化亚硫酸盐还原酶，并纯化190倍。粗提物中最有效的供体是NADH。 NADPH和甲基紫精分别是NADH的40％和30％。氧气可逆地抑制了酶。为了通过NADH发挥最大活性，需要通过凝胶过滤分离的两种高分子量蛋白（分别为360,000和490,000）。间接证据，包括用cysG突变体提取物进行的体外互补实验，表明360,000-Mr组分含有西罗血红素，并且是末端还原酶。将该组分进一步纯化至接近均一，发现由分子量为67,500的单个亚基组成。厌氧亚硫酸还原酶与生物合成亚硫酸还原酶有些相似，但显然具有独特的功能，但尚未确定。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

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