Partial Characterization of Two Cathepsin D Family Aspartic Peptidases of Clonorchis sinensis
10.3347/kjp.2019.57.6.671
- Author:
Jung Mi KANG
1
;
Won Gi YOO
;
Hương Giang LÊ
;
Thị Lam THÁI
;
Sung Jong HONG
;
Woon Mok SOHN
;
Byoung Kuk NA
Author Information
1. Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea. bkna@gnu.ac.kr
- Publication Type:Original Article
- Keywords:
Clonorchis sinensis;
cathepsin D;
aspartic peptidase;
intestine;
egg;
serodiagnostic antigen
- MeSH:
Animals;
Aspartic Acid Endopeptidases;
Biology;
Cathepsin D;
Cathepsins;
Clonorchiasis;
Clonorchis sinensis;
Eggs;
Helminths;
Humans;
Intestines;
Metacercariae;
Ovum;
Parasites;
Peptide Hydrolases;
Rats;
Reproduction
- From:The Korean Journal of Parasitology
2019;57(6):671-680
- CountryRepublic of Korea
- Language:English
-
Abstract:
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 Clonorchis sinensis 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.
