BINDING OF CADMIUM AND ZINC BY A CD/ZN ATPASE INVOLVED IN METAL HYPERACCUMULATIO

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 植物对重金属的吸收不仅在基础研究意义上是一个重要的研究领域，而且因为它对人类营养的影响以及它在污染土壤的植物修复中的应用而成为一个重要的研究领域。对于后一项任务，以及从自然富含金属的土壤中商业提取金属，但不适合常规采矿作业，超级蓄积器工厂至关重要。这些植物能够在其地上部分的干块中积累百分之几的金属；这些植物不同寻常的生理作用是世界范围内密集研究的一个主题。目前这一领域最有趣的研究课题之一是将金属从根部引导到枝条中最终储存位置的转运体的生物化学和生物物理。在本项目中，我们成功地从处于天然状态的超积累植物根中纯化了一个Cd/Zn ATPase(TcHMA4)(Pareswaran等人，2007年)，现在我们想要进一步研究TcHMA4中的哪些配体与金属(在这种情况下是镉)结合。该蛋白属于人类中也存在的P1B型ATPase，该泵家族的几个成员参与了一些重要疾病，如由铜ATPase突变引起的门克斯和威尔逊病。虽然这些基因是已知的，但对P1B型ATPase的生物化学和生物物理知之甚少，因为纯化很难实现。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Heavy metal uptake in plants is an important research area not only in the sense of basic research, but also because of its impact on human nutrition and its application for the phytoremediation of contaminated soils. For the latter task, as well as for the commercial extraction of metals from naturally metal-rich soils that are, however, unsuitable for conventional mining operations, hyperaccumulator plants are of primary importance. These plants are able to accumulate several percent of metals in the dry mass of their above-ground parts; the unusual physiology of these plants is a topic of intensive worldwide research efforts. One of the presently most interesting topics in this area of research are the biochemistry and biophysics of transporters that lead metal from the roots to their final storage site in the shoot. In the current project we successfully purified a Cd/Zn ATPase (TcHMA4) from hyperaccumulator roots in its native state (Parameswaran et al., 2007) and we now want to further investigate which ligands in TcHMA4 bind metal (in this case cadmium). The protein belongs to the P1B-type ATPases that are present in humans as well and several members of this family of pumps are involved in important diseases like the Menkes and Wilsons diseases that are caused by mutation in copper ATPases. While the genes are known, only little is known about biochemistry and biophysics of P1B-type ATPases as the purification is difficult to achieve.