Cysteine-protease activity elicited by Ca2+ stimulus in Plasmodium
Cysteine-protease activity elicited by Ca2+ stimulus in Plasmodium
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DOI：
10.1016/j.molbiopara.2005.01.015
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发表时间：
2005-05-01
影响因子：
1.5
通讯作者：
Garcia, CRS
中科院分区：
文献类型：
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作者：
Farias, SL;Gazarini, ML;Garcia, CRS
血液期疟疾寄生虫需要蛋白水解活性的关键过程，如入侵，血红蛋白降解和裂殖子逃离红细胞（RBC）。我们研究了共聚焦显微镜的存在下，引起的钙刺激在夏氏疟原虫和恶性疟原虫在游离滋养体或红细胞内的寄生虫荧光共振能量转移（FRET）肽的半胱氨酸蛋白酶活性。肽探针的访问，无论是自由或红细胞内寄生虫，也进行了测试，通过选择一系列的荧光肽（653-3146 Da分子量）标记的Abz或FITC。在目前的工作中，我们表明，Ca 2+刺激引起的治疗与褪黑激素，毒胡萝卜素，ionomicin或尼日利亚菌素，促进增加底物水解，这是由特定的半胱氨酸蛋白酶抑制剂E-64和细胞内Ca 2+螯合剂，BAPTA阻断。当用胞质Ca ~（2+）释放化合物处理寄生虫时，半胱氨酸蛋白酶被荧光特异性不可逆抑制剂Ethyl-Eps-Leu-Tyr-Cap-Lys（Abz）-NH_2标记，其中Ethyl-Eps是乙基-（2S，3S）-环氧乙烷-2，3-二羧酸酯。总之，我们证明了夏氏疟原虫和恶性疟原虫具有由Ca 2+引起的细胞质依赖性半胱氨酸蛋白酶活性。(c)2005 Elsevier B. V.保留所有权利。
Bloodstage malaria parasites require proteolytic activity for key processes as invasion, hemoglobin degradation and merozoite escape from red blood cells (RBCs). We investigated by confocal microscopy the presence of cysteine-protease activity elicited by calcium stimulus in Plasmodium chabaudi and Plasmodium falciparum in free trophozoites or for the later parasite within RBC using fluorescence resonance energy transfer (FRET) peptides. Peptide probes access, to either free or intraerythrocytic parasites, was also tested by selecting a range of fluorescent peptides (653-3146 Da molecular mass) labeled with Abz or FITC. In the present work we show that Ca2+ stimulus elicited by treatment with either melatonin, thapsigargin, ionomicin or nigericin, promotes an increase of substrate hydrolysis, which was blocked by the specific cysteine-protease inhibitor E-64 and the intracellular Ca2+ chelator, BAPTA. When parasites were treated with cytoplasmic Ca2+ releasing compounds, a cysteine-protease was labeled in the parasite cytoplasm by the fluorescent specific irreversible inhibitor, Ethyl-Eps-Leu-Tyr-Cap-Lys(Abz)-NH2, where Ethyl-Eps is Ethyl-(2S,3S)-oxirane-2,3-dicarboxylate. In summary, we demonstrate that P. chabaudi and P. falciparum have a cytoplasmic dependent cysteine-protease activity elicited by Ca2+. (c) 2005 Elsevier B.V. All rights reserved.