HYDROLYSIS OF HEMOGLOBIN BY SCHISTSOMA MANSONI CATHEPSIN B-LIKE CYSTEINEPROTEASE

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 研究中心，而研究中心不一定是研究者所在的机构。 在本项目的初步分析中，将纯化的重组血吸虫组织蛋白酶B与血红蛋白孵育，并鉴定血红蛋白降解片段。 最初的切割似乎是在已知被其他血红蛋白降解蛋白酶切割的血红蛋白链的“弱连接”中。随后的降解是快速的，并且仅产生小的肽片段。该研究证实了溶酶体组织蛋白酶B作为“血红蛋白酶”的功效。目前的努力旨在验证血红蛋白和其他宿主血清蛋白作为底物的溶酶体消化蛋白酶在一个更“体内”的设置。在小鼠感染模型中发育后分离的寄生虫肠道内容物正在被分离和分析特定的蛋白质片段。我们正计划确定哪些底物被切割，以及切割位点，以便我们可以使用这些信息来确定可能负责特定切割片段的肠球菌肠道中的推定蛋白酶。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In the initial analysis for this project, purified recombinant Schistosome cathepsin B was incubated with hemoglobin, and fragments of hemoglobin degradation identified. Initial cleavage appeared to be in a "weak link" of the hemoglobin chain known to be cleaved by other hemoglobin degrading proteases. Subsequent degradation was rapid and yielded only small peptide fragments. This study confirmed the efficacy of the schistosome cathepsin B as a "hemoglobinase". Current efforts are aimed at validating hemoglobin and other host-serum proteins as substrates for schistosome digestive proteases in a more "in vivo" setting. Contents of schistosome guts regurgitated following development in mouse models of infection are being separated and analyzed for specific protein fragments. We are planning to identify both what substrates are cleaved, as well as the sites of cleavage so that we can use this information to identify putative proteases from the schistosome gut that may be responsible for specific cleavage fragments.