PDF(Pubmed)
Abstract：
Chagas disease is transmitted to humans by obligatory hematophagous insects of Triatominae subfamily, which feeds on various hosts to acquire their nutritional sustenance derived from blood proteins. Hemoglobin (Hb) digestion is a pivotal metabolic feature of triatomines, representing a key juncture in their competence toward Trypanosoma cruzi; however, it remains poorly understood. To explore the Hb digestion pathway in Rhodnius prolixus, a major Chagas disease vector, we employed an array of approaches for activity profiling of various midgut-associated peptidases using specific substrates and inhibitors. Dissecting the individual contribution of each peptidase family in Hb digestion has unveiled a predominant role played by aspartic proteases and cathepsin B-like peptidases. Determination of peptidase-specific cleavage sites of these key hemoglobinases, in conjunction with mass spectrometry-based identification of in vivo Hb-derived fragments, has revealed the intricate network of peptidases involved in the Hb digestion pathway. This network is initiated by aspartic proteases and subsequently sustained by cysteine proteases belonging to the C1 family. The process is continued simultaneously by amino and carboxypeptidases. The comprehensive profiling of midgut-associated aspartic proteases by quantitative proteomics has enabled the accurate revision of gene annotations within the A1 family of the R. prolixus genome. Significantly, this study also serves to illuminate a potentially important role of the anterior midgut in blood digestion. The expanded repertoire of midgut-associated proteases presented in this study holds promise for the identification of novel targets aimed at controlling the transmission of Chagas disease.
摘要：
恰加斯病是由Triatominae亚科的强制性食血昆虫传播给人类的，它们以各种宿主为食，以获得来自血液蛋白的营养。血红蛋白消化是三叶草的关键代谢特征，代表了他们对克氏锥虫能力的关键时刻；然而，它仍然知之甚少。探索红景天血红蛋白消化途径，查加斯病的主要病媒,我们采用了一系列方法,利用特异性底物和抑制剂对各种中肠相关肽酶进行活性分析.剖析每个肽酶家族在血红蛋白消化中的个体贡献，揭示了天冬氨酸蛋白酶和组织蛋白酶B样肽酶所起的主要作用。确定这些关键血红蛋白酶的肽酶特异性切割位点，结合基于质谱的体内Hb衍生片段的鉴定，揭示了参与Hb消化途径的复杂肽酶网络。该网络由天冬氨酸蛋白酶起始,随后由属于C1家族的半胱氨酸蛋白酶维持。该过程通过氨基和羧肽酶同时继续。通过定量蛋白质组学对中肠相关的天冬氨酸蛋白酶进行全面分析，可以准确地修改R.prolixus基因组A1家族中的基因注释。重要的是,这项研究明确阐明了前肠在血液消化中的模糊作用。这种分解代谢途径的揭示为识别旨在控制查加斯病传播的新型靶标提供了巨大的希望。
