Korean J Parasitol.  2006 Sep;44(3):187-196. 10.3347/kjp.2006.44.3.187.

Molecular and biochemical characterization of hemoglobinase, a cysteine proteinase, in Paragonimus westermani

• Choi JH
• Lee JH
• Yu HS
• Jeong HJ
• Kim J
• Hong YC
• Kong HH
• Chung DI

• KMID: 1720517
• DOI: http://doi.org/10.3347/kjp.2006.44.3.187

Abstract

The mammalian trematode Paragonimus westermani is a typical digenetic parasite, which can cause paragonimiasis in humans. Host tissues and blood cells are important sources of nutrients for development, growth and reproduction of P. westermani. In this study, a cDNA clone encoding a 47 kDa hemoglobinase of P. westermani was characterized by sequencing analysis, and its localization was investigated immunohistochemically. The phylogenetic tree prepared based on the hemoglobinase gene showed high homology with hemoglobinases of Fasciola hepatica and Schistosoma spp. Moreover, recombinant P. westermani hemoglobinase degradaded human hemoglobin at acidic pH (from 3.0 to 5.5) and its activity was almost completely inhibited by E-64, a cysteine proteinase inhibitor. Immunohistochemical studies showed that P. westermani hemoglobinase was localized in the epithelium of the adult worm intestine implying that the protein has a specific function. These observations suggest that hemoglobinase may act as a digestive enzyme for acquisition of nutrients from host hemoglobin. Further investigations may provide insights into hemoglobin catabolism in P. westermani.

Keyword

Paragonimus westermani; lung fluke; cysteine proteinase; hemoglobinase

MeSH Terms

Sequence Alignment
Recombinant Proteins/biosynthesis/genetics
Phylogeny
Paragonimus westermani/*enzymology/genetics
Molecular Sequence Data
Hemoglobins/metabolism
Escherichia coli/enzymology/genetics
DNA, Complementary/genetics
Cysteine Endopeptidases/*genetics/immunology/*metabolism
Astacoidea/parasitology
Antigens, Helminth/genetics/immunology/metabolism
Animals
Amino Acid Sequence