Cephalopod Hemocyanins: Structure and Function

项目建议继续研究头足类动物血青素的结构、进化和功能，有限地扩展最近关于章鱼血青素的工作，以及涉及鹦鹉螺和Loligo鱿鱼血青素的重大新项目。最初，某些正在进行的章鱼血青素研究将完成。这些实验包括利用裂解亚单位作为探索功能行为的工具。将对鹦鹉螺和Loligo血色素的亚基结构进行详细分析，以提供PI为章鱼开发的完整结构图。将确定每种情况下涉及的多肽链的种类数量，以及每条链上的功能单元的数量。多种链类型在装配中的作用将被评估。有限的肽测序将进行，以允许对齐的Loligo和鹦鹉螺单位与章鱼和腹足类血青素。如果时间和资金允许，建议重新检查Loligo血青素的氧结合功能和变变，因为早期的研究表明了一个显着的氧连接解离过程。这个缓慢的过程应该允许对血青素解离反应的第一个动力学研究。

The PI proposes to continue studies of the structure, evolution, and function of cephalopod hemocyanins with limited extension of recent work on Octopus hemocyanin and major new projects involving the hemocyanins of Nautilus and of the squid Loligo. Initially, certain ongoing studies of Octopus hemocyanin will be brought to completion. These include experiments utilizing cleaved subunits as tools in exploration of functional behavior. A detailed analysis of the subunit structure of the Nautilus and Loligo hemocyanins will be undertaken, to provide the kind of complete structural picture the PI has developed for Octopus. The number of kinds of polypeptide chains involved in each case, and the number of functional units in each chain will be determined. The roles of multiple chain types in assembly will be assessed. Limited peptide sequencing will be carried out in order to allow alignment of the Loligo and Nautilus units with those of Octopus and with those in gastropod hemocyanins. If time and funds permit, a re-examination of the oxygen-binding function and allostery of Loligo hemocyanin is proposed, since early studies indicated a remarkable oxygen-linked dissociation process. This slow process should allow the first kinetic studies on a hemocyanin dissociation reaction.