HYDROLYSIS OF HEMOGLOBIN BY SCHISTSOMA MANSONI CATHEPSIN B-LIKE CYSTEINEPROTEASE

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 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. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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.