期刊
MOLECULAR AND BIOCHEMICAL PARASITOLOGY
卷 167, 期 1, 页码 60-71出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.molbiopara.2009.04.010
关键词
Fasciola gigantica; Cysteine protease inhibitor; Cystatin; Nucleic acid analyses; Immunolocalization; Immunodepletion; 2D-proteomics; Protein activity; Protein quantitation
资金
- Thammasat University
- Thailand Research Fund through a Royal Golden jubilee Ph.D. scholarship
In the present study we describe type 1 cystatin, a cysteine protease inhibitor, as a major released antigen of the tropical liver fluke Fasciola gigantica (FgStefin-1). Immunohistochemical analysis showed that FgStefin-1 is abundant in (a) tissue of tegumental type, including oral and ventral sucker, pharynx, genital atrium, metraterm, cirrus and (b) the intestinal epithelium. Faint staining was observed in the epithelia of ovary and proximal uterus. Immunoblots showed the presence of FgStefin-1 in the parasite's excretion/secretion (ES) product and immunodepletion demonstrated that FgStefin-1 herein is partially complexed with cathepsin L Furthermore, quantitation of FgStefin-1 in comparison to cathepsin L in ES product and crude worm extract of adults supports a major external function of FgStefin-1 with an estimated 50% being released in at least equimolar amounts to cathepsin L Sera of an experimentally infected rabbit reacted with recombinant FgStefin-1 starting 8 weeks postinfection. Activity analyses of recombinant FgStefin-1 showed nanomolar inhibition constants for mammalian cathepsin B, L, and S cysteine proteases and released cysteine proteases of the parasite. The protein is active over a wide pH range and is heat stable. Our results suggest protective functions of FgStefin-1, regulating intracellular cysteine protease activity, and possibly protection against extracellular proteolytic damage to the parasite's intestinal and tegumental surface proteins. Considering inhibition kinetics and previously demonstrated immunomodulatory properties of cystatin in parasitic nematodes a comparable function of FgStefin-1 is suggested and is at present under investigation. (C) 2009 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据