Characterization of the human serum trypanosome toxin, haptoglobin-related protein
Characterization of the human serum trypanosome toxin, haptoglobin-related protein
复制标题
DOI：
10.1074/jbc.273.7.3884
复制
发表时间：
1998-02-13
影响因子：
4.8
通讯作者：
Tomlinson, S
中科院分区：
文献类型：
--
作者：
Muranjan, M;Nussenzweig, V;Tomlinson, S
结合珠蛋白相关蛋白（HPR）是一种与急性期反应物结合珠蛋白（Hp）同源性> 90%的血清蛋白。结合珠蛋白结合并从循环中除去游离血红蛋白（Hb），在一些癌症患者的血清中Hpr水平随着肿瘤进展而升高，但该观察结果的相关性尚不清楚。HPR是两种不同的高分子量复合物（锥虫溶解因子1（TLF 1）和TLF 2）的组成部分，它们溶解非洲寄生虫布氏锥虫。以前的数据表明，HPR代表两种锥虫溶解因子的毒性成分。有人提出，被寄生虫摄取后，结合到HPR的Hb在过氧化物酶依赖的过程中引起溶解。我们报告，在正常人血清中的HPR的分子结构不同于Rp的分子结构，并且HPR不结合正常人血清中的Hb。免疫耗竭所有可检测到的血红蛋白从TLF 1不耗尽TLF 1的HPR或锥虫溶解活性，这表明，寄生虫裂解的机制是血红蛋白独立的。
Haptoglobin-related protein (HPR) is a serum protein that is > 90% homologous to the acute-phase reactant haptoglobin (Hp). Haptoglobin binds and removes free hemoglobin (Hb) from the circulation, Hpr levels are elevated with tumor progression in the serum of some cancer patients, but the relevance of this observation is not understood. HPR is an integral part of two distinct high molecular weight complexes (trypanosome lytic factor 1 (TLF1) and TLF2) that are lytic for the African parasite Tryanosoma brucei brucei. Previous data indicate that HPR represents the toxic component of both trypanosoma lytic factors. It has been proposed that after uptake by the parasite, Hb bound to HPR causes lysis in a peroxidase-dependent process, We report that the molecular architecture of HPR in normal human serum is different from that of Rp and that HPR does not bind Hb in normal human serum. Immunodepletion of all detectable Hb from TLF1 does not deplete TLF1 of HPR or trypanolytic activity, suggesting that; the mechanism of parasite lysis is Hb-independent.