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

许多地方表层海水中存在溶解铜 主要是在与强有机配体的络合物中， 以它们的络合强度为特征。 但这些 配体从未被分离和表征;因此，几乎 我们对其化学性质一无所知。 分离与 这些配体的表征对我们来说非常重要。 对铜的地球化学循环的认识， 配体本身，也许还有其他金属， 同样复杂。 最近，固定化金属（Cu 2+）亲和 层析（IMAC）已被用于纯化细胞外铜- 海洋细菌产生的结合蛋白， 并部分表征有机化合物， 来自河口、沿海和公海沃茨的铜。 IMAC- 孤立的配体具有类似于 在大西洋和太平洋强烈络合铜的配体。 这 试点项目将确定IMAC是否使用已建立的 或改进的方案，可以分离这些配体， 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）。 适当的IMAC协议 然后将与DPASV和LC/DPCSV结合使用， 表征沿海表层海水中的配体， 到：它们的浓度，条件稳定常数， 包含它们的蛋白质和多糖的相对比例， 和分子量。

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.