金属蛋白在包括呼吸、光合作用和药物代谢在内的很过生物过程中扮演关键角色。在一种蛋白分子被完全定性之前，其中一个金属的存在经常并不明显，由于这个原因，同时也由于金属协调点的多样性，目前还没有可能利用基因组序列来根据一种生物所处环境或该生物的金属蛋白组成预测其所利用的金属类型。
因此，Cvetkovic等人采用了另外一种途径，利用传统液相色谱来识别一种生物（超嗜热海洋古细菌Pyrococcus furiosus）中的金属，利用蛋白组学方法来研究金属蛋白。在色谱的343个金属峰中，158个与任何已知的或预测的金属蛋白都不匹配，包括以前并不知道该生物所能够利用的金属。这项工作表明，金属蛋白要比我们以前所认为的更为广泛和多样。（生物谷Bioon.com）
生物谷推荐原文出处：
Nature doi:10.1038/nature09265
Microbial metalloproteomes are largely uncharacterized
Aleksandar Cvetkovic,Angeli Lal Menon,Michael P. Thorgersen,Joseph W. Scott,Farris L. Poole II,Francis E. Jenney Jr,W. Andrew Lancaster,Jeremy L. Praissman,Saratchandra Shanmukh,Brian J. Vaccaro,Sunia A. Trauger,Ewa Kalisiak,Junefredo V. Apon,Gary Siuzdak,Steven M. Yannone,John A. Tainer& Michael W. W. Adams
Metal ion cofactors afford proteins virtually unlimited catalytic potential, enable electron transfer reactions and have a great impact on protein stability1, 2. Consequently, metalloproteins have key roles in most biological processes, including respiration (iron and copper), photosynthesis (manganese) and drug metabolism (iron). Yet, predicting from genome sequence the numbers and types of metal an organism assimilates from its environment or uses in its metalloproteome is currently impossible because metal coordination sites are diverse and poorly recognized2, 3, 4. We present here a robust, metal-based approach to determine all metals an organism assimilates and identify its metalloproteins on a genome-wide scale. This shifts the focus from classical protein-based purification to metal-based identification and purification by liquid chromatography, high-throughput tandem mass spectrometry (HT-MS/MS) and inductively coupled plasma mass spectrometry (ICP-MS) to characterize cytoplasmic metalloproteins from an exemplary microorganism (Pyrococcus furiosus). Of 343 metal peaks in chromatography fractions, 158 did not match any predicted metalloprotein. Unassigned peaks included metals known to be used (cobalt, iron, nickel, tungsten and zinc; 83 peaks) plus metals the organism was not thought to assimilate (lead, manganese, molybdenum, uranium and vanadium; 75 peaks). Purification of eight of 158 unexpected metal peaks yielded four novel nickel- and molybdenum-containing proteins, whereas four purified proteins contained sub-stoichiometric amounts of misincorporated lead and uranium. Analyses of two additional microorganisms (Escherichia coli and Sulfolobus solfataricus) revealed species-specific assimilation of yet more unexpected metals. Metalloproteomes are therefore much more extensive and diverse than previously recognized, and promise to provide key insights for cell biology, microbial growth and toxicity mechanisms.
