Isolation of Copper-Complexing Organic Ligands from Seawaterand Characterization of Their Copper-Complexation Characteristics

海水中铜络合有机配体的分离及其铜络合特性的表征

• 批准号: 9216882
• 负责人: John Donat
• 金额: $ 14.94万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9216882&HistoricalAwards=false
• 关键词: Isolation; Copper; Complexing; Organic; Ligands

Dissolved copper in surface seawater in many locations exists primarily in complexes with strong organic ligands, which are distinguished by their complexing strengths. However, these ligands have never been isolated and characterized; thus, almost nothing is known about their chemical nature. Isolation and characterization of these ligands is extremely important to our understanding of the biogeochemical cycling of copper and the ligands themselves, and perhaps that of other metals which may be similarly complexed. Recently, immobilized metal (Cu2+) affinity chromatography (IMAC) has been used to purify extracellular copper- binding proteins produced by marine bacteria, and also to isolate and partially characterize organic compounds with affinity for copper from estuarine, coastal, and open ocean waters. IMAC- isolated ligands have depth distributions similar to those of ligands that strongly complex Cu in the Atlantic and Pacific. This pilot project will determine whether IMAC, using either established or modified protocols, can isolate these ligands, ligands detected in seawater by differential pulse anodic stripping voltammetry (DPASV) and ligand competition/differential pulse cathodic stripping voltammetry (LC/DPCSV). The appropriate IMAC protocol will then be used in conjunction with DPASV and LC/DPCSV to characterize the ligands in coastal surface seawater with respect to: their concentrations, conditional stability constants, relative proportions of protein and polysaccharide comprising them, and molecular weight.

在海水表层的许多地方，溶解的铜主要存在于与强有机配体的配合物中，这些配合物的特点是它们的络合强度。然而，这些配体从未被分离和表征过；因此，人们对它们的化学性质几乎一无所知。这些配体的分离和表征对于我们理解铜和配体本身的生物地球化学循环，以及其他可能类似络合的金属的生物地球化学循环至关重要。近年来，固定化金属（Cu2+）亲和层析（IMAC）已被用于纯化海洋细菌产生的胞外铜结合蛋白，以及分离和部分表征来自河口、沿海和开放海域的对铜具有亲和性的有机化合物。IMAC-分离配体的深度分布与大西洋和太平洋中强络合Cu的配体相似。该试点项目将确定IMAC是否可以使用已建立或修改的方案分离这些配体，这些配体是通过差分脉冲阳极溶出伏安法（DPASV）和配体竞争/差分脉冲阴极溶出伏安法（LC/DPCSV）在海水中检测到的。然后，适当的IMAC方案将与DPASV和LC/DPCSV一起使用，以表征沿海表面海水中的配体，包括：它们的浓度、条件稳定性常数、组成它们的蛋白质和多糖的相对比例以及分子量。