Next Article in Journal
Caloric Restriction Protects against Lactacystin-Induced Degeneration of Dopamine Neurons Independent of the Ghrelin Receptor
Next Article in Special Issue
TrmFO, a Fibronectin-Binding Adhesin of Mycoplasma bovis
Previous Article in Journal
Immunological Features of Respiratory Syncytial Virus-Caused Pneumonia—Implications for Vaccine Design
Previous Article in Special Issue
L1198F Mutation Resensitizes Crizotinib to ALK by Altering the Conformation of Inhibitor and ATP Binding Sites
Article Menu
Issue 3 (March) cover image

Export Article

Open AccessArticle
Int. J. Mol. Sci. 2017, 18(3), 557; doi:10.3390/ijms18030557

Molecular and Structural Characterization of the Tegumental 20.6-kDa Protein in Clonorchis sinensis as a Potential Druggable Target

Division of Malaria and Parasitic Diseases, Centre for Immunology and Pathology, Korea National Research Institute of Health, Chungbuk 28159, Korea
Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727, Korea
These authors contributed equally to this work.
Current address: Department of Medical Environmental Biology, Chung-Ang University College of Medicine, Seoul 06974, Korea.
Author to whom correspondence should be addressed.
Academic Editors: Tatyana Karabencheva-Christova and Christo Z. Christov
Received: 31 January 2017 / Revised: 24 February 2017 / Accepted: 28 February 2017 / Published: 4 March 2017
(This article belongs to the Collection Proteins and Protein-Ligand Interactions)
View Full-Text   |   Download PDF [8614 KB, uploaded 4 March 2017]   |  


The tegument, representing the membrane-bound outer surface of platyhelminth parasites, plays an important role for the regulation of the host immune response and parasite survival. A comprehensive understanding of tegumental proteins can provide drug candidates for use against helminth-associated diseases, such as clonorchiasis caused by the liver fluke Clonorchis sinensis. However, little is known regarding the physicochemical properties of C. sinensis teguments. In this study, a novel 20.6-kDa tegumental protein of the C. sinensis adult worm (CsTegu20.6) was identified and characterized by molecular and in silico methods. The complete coding sequence of 525 bp was derived from cDNA clones and encodes a protein of 175 amino acids. Homology search using BLASTX showed CsTegu20.6 identity ranging from 29% to 39% with previously-known tegumental proteins in C. sinensis. Domain analysis indicated the presence of a calcium-binding EF-hand domain containing a basic helix-loop-helix structure and a dynein light chain domain exhibiting a ferredoxin fold. We used a modified method to obtain the accurate tertiary structure of the CsTegu20.6 protein because of the unavailability of appropriate templates. The CsTegu20.6 protein sequence was split into two domains based on the disordered region, and then, the structure of each domain was modeled using I-TASSER. A final full-length structure was obtained by combining two structures and refining the whole structure. A refined CsTegu20.6 structure was used to identify a potential CsTegu20.6 inhibitor based on protein structure-compound interaction analysis. The recombinant proteins were expressed in Escherichia coli and purified by nickel-nitrilotriacetic acid affinity chromatography. In C. sinensis, CsTegu20.6 mRNAs were abundant in adult and metacercariae, but not in the egg. Immunohistochemistry revealed that CsTegu20.6 localized to the surface of the tegument in the adult fluke. Collectively, our results contribute to a better understanding of the structural and functional characteristics of CsTegu20.6 and homologs of flukes. One compound is proposed as a putative inhibitor of CsTegu20.6 to facilitate further studies for anthelmintics. View Full-Text
Keywords: Clonorchis sinensis; tegument; homology modelling; I-TASSER; structure; localization; virtual screening; docking; compound Clonorchis sinensis; tegument; homology modelling; I-TASSER; structure; localization; virtual screening; docking; compound

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Kim, Y.-J.; Yoo, W.G.; Lee, M.-R.; Kang, J.-M.; Na, B.-K.; Cho, S.-H.; Park, M.-Y.; Ju, J.-W. Molecular and Structural Characterization of the Tegumental 20.6-kDa Protein in Clonorchis sinensis as a Potential Druggable Target. Int. J. Mol. Sci. 2017, 18, 557.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top