...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Chemosphere >Stereochemistry of LinB-catalyzed biotransformation of δ-HBCD to 1R,2R,5S,6R,9R,10S-pentabromocyclododecanol
【24h】

Stereochemistry of LinB-catalyzed biotransformation of δ-HBCD to 1R,2R,5S,6R,9R,10S-pentabromocyclododecanol

机译：LinB催化的δ-六溴环十二烷生物转化为1R，2R，5S，6R，9R，10S-五溴环十二烷的立体化学

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The haloalkane dehalogenase LinB from Sphingobium indicum B90A converts p-hexachlorocydohexane (β-HCH), the most persistent HCH stereoisomer, to mono- and dihydroxylated metabolites. Recently, we reported that LinB also transforms α-, β- and γ-hexabromocyclododecanes (HBCDs), which are structurally related to HCHs. Here, we show that LinB catalyzes the hydroxylation of 8-HBCD to two pentab-romocyclododecanols (PBCDOHs) and two tetrabromocyclododecadiols (TBCDDOHs). The stereochemistry of this enzymatic transformation was deduced from XRD crystal structure data of the substrate δ-HBCD and α_2-PBCDOH, one of the biotransformation products. Five stereocenters of δ-HBCD are unchanged but the one at C6 is converted to an alcohol with inversion from S- to R-configuration in a nudeophilic, S_N2-like substitution reaction. Only α_2-PBCDOH with the 1R,2R,5S,6R,9R,10S-configuration is obtained but not its enantiomer. With only two of the 64 PBCDOHs formed, these transformations indeed are regio- and stereoselective. A conformational analysis revealed that the triple-turn motive, which is predominant in δ-HBCD and in several other HBCD stereoisomers, is also found in the product. This shows that LinB preferentially converted reactive bromine atoms but not those in the conserved triple-turn motive. The widespread contamination with HCHs triggered the bacterial evolution of dehalo-genases which acquired the ability to convert these pollutants and their metabolites. We here demonstrate that LinB of S. indicum also transforms HBCDs regio- and stereoselectively following a similar mechanism.
机译：来自印度鞘氨醇鞘氨醇B90A的卤代烷脱卤酶LinB将最持久的HCH立体异构体对六氯环己烷（β-HCH）转化为单羟基和二羟基代谢产物。最近，我们报道了LinB还可以转化与六氯环乙烷结构相关的α-，β-和γ-六溴环十二烷（HBCD）。在这里，我们显示LinB催化8-HBCD羟基化为两个五溴环十二烷醇（PBCDOHs）和两个四溴环十二碳二烯二醇（TBCDDOHs）。该酶促转化的立体化学是根据底物δ-HBCD和α_2-PBCDOH（一种生物转化产物）的XRD晶体结构数据推导出的。 δ-HBCD的五个立体中心不变，但在亲核的类S_N2取代反应中，C6的一个立体中心被S-构型转化为醇。仅获得具有1R，2R，5S，6R，9R，10S构型的α_2-PBCDOH，但没有获得其对映异构体。仅形成64种PBCDOH中的两种，这些转化确实具有区域选择性和立体选择性。构象分析表明，在产物中还发现了以δ-HBCD和其他几种HBCD立体异构体为主的三转动机。这表明LinB优先转化了反应性溴原子，而不是保守的三转动机中的那些。六氯环己烷的广泛污染触发了脱卤酶的细菌进化，脱卤酶具有转化这些污染物及其代谢产物的能力。我们在这里证明了印度血吸虫的LinB也遵循类似的机制在区域和立体选择性上转化了HBCD。

著录项

  • 来源
    《Chemosphere》 |2013年第6期|1911-1919|共9页
  • 作者

    Norbert V. Heeb; Daniel Zindel; Heidi Graf; Valeria Azara; W. Bernd Schweizer; Birgit Geueke; Hans-Peter E. Kohler; Peter Lienemann;

  • 作者单位

    Swiss Federal Institute for Materials Science and Technology (Empa), Laboratory of Analytical Chemistry, UEberlandstrasse 129, CH-8600 Diibendorf, Switzerland;

    Swiss Federal Institute for Materials Science and Technology (Empa), Laboratory of Analytical Chemistry, UEberlandstrasse 129, CH-8600 Diibendorf, Switzerland,Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, Reidbach, 8820 WSdenswil, Switzerland;

    Swiss Federal Institute for Materials Science and Technology (Empa), Laboratory of Analytical Chemistry, UEberlandstrasse 129, CH-8600 Diibendorf, Switzerland,Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, Reidbach, 8820 WSdenswil, Switzerland;

    Swiss Federal Institute for Materials Science and Technology (Empa), Laboratory of Analytical Chemistry, UEberlandstrasse 129, CH-8600 Diibendorf, Switzerland;

    Swiss Federal Institute of Technology (ETH), Laboratory for Organic Chemistry, Hoenggerberg, 8093 Zuerich, Switzerland;

    Swiss Federal Institute of Aquatic Research and Technology (Eawag), UEberlandstrasse 133, CH-8600 Duebendorf, Switzerland;

    Swiss Federal Institute of Aquatic Research and Technology (Eawag), UEberlandstrasse 133, CH-8600 Duebendorf, Switzerland;

    Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, Reidbach, 8820 WSdenswil, Switzerland;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    brominated flame retardants; HBCD transformation; crystal structure; HCH-converting enzymes;

    机译：溴化阻燃剂;六溴环十二烷转化;晶体结构六氯环己烷转化酶;

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