Molecular and Biochemical Properties of a Cysteine Protease of Acanthamoeba castellanii
10.3347/kjp.2018.56.5.409
- Author:
Yeonchul HONG
1
;
Jung Mi KANG
;
So Young JOO
;
Su Min SONG
;
Hương Giang LÊ
;
Thị Lam THÁI
;
Jinyoung LEE
;
Youn Kyoung GOO
;
Dong Il CHUNG
;
Woon Mok SOHN
;
Byoung Kuk NA
Author Information
1. Department of Parasitology and Tropical Medicine, Kyungpook National University School of Medicine, Daegu 41944, Korea. ychong@knu.ac.kr
- Publication Type:Original Article
- Keywords:
Acanthamoeba castellanii;
cysteine protease;
lysosome;
trophozoite;
cyst
- MeSH:
Acanthamoeba castellanii;
Acanthamoeba;
Cathepsin L;
Cathepsins;
Cysteine Proteases;
Cysteine;
Fibronectins;
Genes, vif;
Humans;
Hydrogen-Ion Concentration;
Lysosomes;
Sequence Analysis;
Trophozoites;
Virulence
- From:The Korean Journal of Parasitology
2018;56(5):409-418
- CountryRepublic of Korea
- Language:English
-
Abstract:
Acanthamoeba spp. are free-living protozoa that are opportunistic pathogens for humans. Cysteine proteases of Acanthamoeba have been partially characterized, but their biochemical and functional properties are not clearly understood yet. In this study, we isolated a gene encoding cysteine protease of A. castellanii (AcCP) and its biochemical and functional properties were analyzed. Sequence analysis of AcCP suggests that this enzyme is a typical cathepsin L family cysteine protease, which shares similar structural characteristics with other cathepsin L-like enzymes. The recombinant AcCP showed enzymatic activity in acidic conditions with an optimum at pH 4.0. The recombinant enzyme effectively hydrolyzed human proteins including hemoglobin, albumin, immunoglobuins A and G, and fibronectin at acidic pH. AcCP mainly localized in lysosomal compartment and its expression was observed in both trophozoites and cysts. AcCP was also identified in cultured medium of A. castellanii. Considering to lysosomal localization, secretion or release by trophozoites and continuous expression in trophozoites and cysts, the enzyme could be a multifunctional enzyme that plays important biological functions for nutrition, development and pathogenicity of A. castellanii. These results also imply that AcCP can be a promising target for development of chemotherapeutic drug for Acanthamoeba infections.
