Cathepsin D (CatD, EC 3.4.23.5) is a member belonging to the subfamily of aspartic endopeptidases, which are classified into the MEROPS clan AA, family A1. Helminth parasites express a large set of different peptidases that play pivotal roles in parasite biology and pathophysiology. However, CatD is less well known than the other classes of peptidases in terms of biochemical properties and biological functions. In this study, we identified 2 novel CatDs (CsCatD1 and CsCatD2) of Clonorchissinensis and partially characterized their properties. Both CsCatDs represent typical enzymes sharing amino acid residues and motifs that are tightly conserved in the CatD superfamily of proteins. Both CsCatDs showed similar patterns of expression in different developmental stages of C. sinensis, but CsCatD2 was also expressed in metacercariae. CsCatD2 was mainly expressed in the intestines and eggs of C. sinensis. Sera obtained from rats experimentally infected with C. sinensis reacted with recombinant CsCatD2 beginning 2 weeks after infection and the antibody titers were gradually increased by maturation of the parasite. Structural analysis of CsCatD2 revealed a bilobed enzyme structure consisting of 2 antiparallel β-sheet domains packed against each other forming a homodimeric structure. These results suggested a plausible biological role of CsCatD2 in the nutrition and reproduction of parasite and its potential utility as a serodiagnostic antigen in clonorchiasis.
Citations
Citations to this article as recorded by
Clonorchis sinensis excretory/secretory proteins ameliorate inflammation in rheumatoid arthritis and ankylosing spondylitis Moon-Ju Kim, Hee Min Yoo, Yu Jeong Lee, Hyun Hee Jang, Seung Cheol Shim, Eun Jeong Won, Tae-Jong Kim Parasites & Vectors.2025;[Epub] CrossRef
Proteomic analysis of extracellular vesicles and extracellular vesicle-depleted excretory-secretory products of Toxocara canis and Toxocara cati larval cultures Timothy K. Wu, Qin Fu, Janice L. Liotta, Dwight D. Bowman Veterinary Parasitology.2024; 332: 110331. CrossRef
An insight into the functional genomics and species classification of Eudiplozoon nipponicum (Monogenea, Diplozoidae), a haematophagous parasite of the common carp Cyprinus carpio Jiří Vorel, Nikol Kmentová, Christoph Hahn, Petr Bureš, Martin Kašný BMC Genomics.2023;[Epub] CrossRef
In silico identification of excretory/secretory proteins and drug targets in monogenean parasites Víctor Caña-Bozada, Martha Chapa-López, Rubén D. Díaz-Martín, Alejandra García-Gasca, José Ángel Huerta-Ocampo, Guillermo de Anda-Jáuregui, F. Neptalí Morales-Serna Infection, Genetics and Evolution.2021; 93: 104931. CrossRef
pH-Dependent Structural Dynamics of Cathepsin D-Family Aspartic Peptidase of Clonorchis sinensis Jung-Mi Kang, Hương Giang Lê, Byoung-Kuk Na, Won Gi Yoo Pathogens.2021; 10(9): 1128. CrossRef
Dopaminergic antagonists inhibit bile chemotaxis of adult Clonorchis sinensis and its egg production Fuhong Dai, Jin-Ho Song, Yeon Pyo Hong, Xuelian Bai, Woon-Mok Sohn, Sung-Jong Hong, jong-Yil Chai PLOS Neglected Tropical Diseases.2020; 14(3): e0008220. CrossRef
Identification and Analysis of the Tegument Protein and Excretory-Secretory Products of the Carcinogenic Liver Fluke Clonorchis sinensis Yunliang Shi, Kai Yu, Anli Liang, Yan Huang, Fangqi Ou, Haiyan Wei, Xiaoling Wan, Yichao Yang, Weiyu Zhang, Zhihua Jiang Frontiers in Microbiology.2020;[Epub] CrossRef