Seawater Proteomics

虽然大量的碳以溶解有机物（DOM）的形式储存在海洋中，但这种异质性的碳库的复杂性意味着人们对高分子量有机物在分子水平上的了解很少，这种缺乏阻碍了对控制其循环的机制的更详细的了解。来自西弗吉尼亚大学和波多黎各大学的科学家们合作研究DOM的一个重要组成部分，即海洋中溶解的蛋白质。 尽管蛋白质只是DOM的一小部分，但它是溶解有机氮池的主要成分，这些氮来自细胞溶解或排泄等过程。他们将利用蛋白质组学分析的巨大进步，使用最先进的质谱分析对海洋蛋白质进行测序和鉴定。将使用傅立叶变换质谱法分析完整蛋白质，以评估凝胶电泳分离的蛋白质条带的复杂性。因此，通过从头测序获得的肽标签的可靠性和特异性将得到改善。直接的数据库匹配和同源性搜索应该会产生溶解蛋白质来源的重要线索。将对数据进行检索，以寻找表明存在翻译后蛋白质修饰的证据。将对已识别的修饰进行表征，以确定它们是否是常见的生物学修饰，或者它们是否似乎是非生物过程的结果。成功地将这些技术转移到海洋将为解决有关有机氮的来源和变化的长期问题开辟道路，有机氮是海洋生物氮的重要储存库。 就更广泛的影响而言，这项研究的结果将开始将迅速成熟的蛋白质组学技术应用于海洋中有机氮的化学性质，利用新兴的海洋生物基因组序列的知识。 作为本研究的一部分，一名研究生和一名接受化学海洋学培训的博士后将接受这些新技术的培训。

ABSTRACTOCE-0453737Although large amounts of carbon are stored in the oceans as dissolved organic matter (DOM), the complexity of this heterogeneous pool has meant that little is known about the high molecular weight organic matter at the molecular level, and this lack has hindered a more detailed understanding of the mechanisms that control its cycling. Scientists from the University of West Virginia and from the University of Puerto Rico have teamed up to study an important component of DOM, the dissolved proteins in the ocean. Although only a small fraction of the DOM, proteins are, however, a primary component of the dissolved organic nitrogen pool that arises from processes such as cell lysis or excretion. They will take advantage of the dramatic improvements in proteomic analysis to sequence and identify marine proteins using state-of-the-art mass spectrometric analysis. Intact proteins will be analyzed with Fourier transform mass spectrometry to access the complexity of protein bands separated by gel electrophoresis. The reliability and specificity of peptide tags obtained through de novo sequencing will hence be improved. Direct database matching and homology searching should yield important clues to the sources of dissolved proteins. The data will be searched for evidence suggesting the presence of post-translational protein modifications. Identified modifications will be characterized to determine if they are common biological modifications or if they appear to be the result of abiotic processes. Successful transfer of these techniques to the ocean will open the way for resolution of longstanding issues concerning the sources and changes in organic nitrogen, an important reservoir of nitrogen for marine life. In terms of broader impacts, results from this study will begin to apply the rapidly maturing technology of proteomics to the chemistry of organic nitrogen in the oceans, leveraging knowledge from the burgeoning genomic sequences of marine organisms. A graduate student, and a postdoctoral fellow with training in Chemical Oceanography, will be trained in these new techniques as part of this study.