Ta Binh T T, Nguyen D Linh, Jala Isabelle, Dontumprai Rieofarng, Plumworasawat Sirikanya, Aighewi Omorose, Ong Emily, Shawley Audrey, Potriquet Jeremy, Saichua Prasert, van Diepen Angela, Sripa Banchob, Hokke Cornelis H, Suttiprapa Sutas
Tropical Medicine Graduate Program, Academic Affairs, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, the Netherlands.
Parasitol Int. 2020 Apr;75:102050. doi: 10.1016/j.parint.2019.102050. Epub 2019 Dec 31.
The carcinogenic liver fluke Opisthorchis viverrini (O. viverrini) is endemic in Thailand and neighboring countries including Laos PDR, Vietnam and Cambodia. Infections with O. viverrini lead to hepatobiliary abnormalities including bile duct cancer-cholangiocarcinoma (CCA). Despite decades of extensive studies, the underlying mechanisms of how this parasite survives in the bile duct and causes disease are still unclear. Therefore, this study aims to identify and characterize the most abundant protein secreted by the parasite. Proteomics and bioinformatics analysis revealed that the most abundant secretory protein is a metallopeptidase, named Ov-M60-like-1. This protein contains an N-terminal carbohydrate-binding domain and a C-terminal M60-like domain with a zinc metallopeptidase HEXXH motif. Further analysis by mass spectrometry revealed that Ov-M60-like-1 is N-glycosylated. Recombinant Ov-M60-like-1 (rOv-M60-like-1) expressed in Escherichia coli (E. coli) was able to digest bovine submaxillary mucin (BSM). The mucinase activity was inhibited by the ion chelating agent EDTA, confirming its metallopeptidase identity. The enzyme was active at temperatures ranging 25-37 °C in a broad pH range (pH 2-10). The identification of Ov-M60-like-1 mucinase as the major secretory protein of O. viverrini worms warrants further research into the role of this glycoprotein in the pathology induced by this carcinogenic worm.
致癌肝吸虫华支睾吸虫（O. viverrini）在泰国及包括老挝人民民主共和国、越南和柬埔寨在内的周边国家呈地方性流行。感染华支睾吸虫会导致肝胆异常，包括胆管癌——胆管癌（CCA）。尽管经过了数十年的广泛研究，但这种寄生虫如何在胆管中存活并引发疾病的潜在机制仍不清楚。因此，本研究旨在鉴定和表征该寄生虫分泌的最丰富的蛋白质。蛋白质组学和生物信息学分析表明，最丰富的分泌蛋白是一种金属肽酶，命名为Ov-M60-like-1。该蛋白包含一个N端碳水化合物结合结构域和一个C端M60样结构域，带有锌金属肽酶HEXXH基序。质谱进一步分析表明Ov-M60-like-1是N-糖基化的。在大肠杆菌（E. coli）中表达的重组Ov-M60-like-1（rOv-M60-like-1）能够消化牛颌下粘蛋白（BSM）。离子螯合剂EDTA抑制了粘蛋白酶活性，证实了其金属肽酶身份。该酶在25-37°C的温度范围内、较宽的pH范围（pH 2-10）内具有活性。鉴定出Ov-M60-like-1粘蛋白酶是华支睾吸虫蠕虫的主要分泌蛋白，这使得有必要进一步研究这种糖蛋白在这种致癌蠕虫诱发的病理学中的作用。
