Clinical Microbiology: Open Access

Molecular and biochemical characterization of stefin-2 from the liver fluke Fasciola gigantica

6^th Clinical Microbiology Conference

October 20-22, 2016 Rome, Italy

Sinee Siricoon

Thammasat University, Thailand

Posters & Accepted Abstracts: Clin Microbiol

Abstract:

Cystatins are the inhibitors of papain-like cysteine proteases and serve various important physiological functions including modulation of normal proteolytic processes, balance of the host-parasite interaction and defense against pathogens. This research was conducted to characterize the molecular and biochemical properties of a type I cystatin (Stefin-2) in the liver fluke F. gigantica. The cDNA encoding FgStefin-2 had a size of 887 bp and contained a 351 bp open reading frame. The bacterial expression and purification resulted in highly pure rFgStefin-2 with an expected molecular mass of 13-14 kDa. The rFgStefin-2 was used for cysteine protease inhibition assays and polyclonal antibody production. The polyclonal antibody was used to study the distribution of native FgStefin-2 in 2 and 4-week-old juveniles and used in immunoblots. Immunohistochemical analysis showed that FgStefin-2 is located in several tissues of the parasite including the prostate gland, gut epithelium and intrauterine eggs. The polyclonal antibody reacted with rFgStefin-2, CW extract and ES product of the adult parasite but did not cross-react with CW extracts of other trematodes. Mouse antisera raised against rFgStefin-2, rFgMDCd10 and rFgStefin-1 showed no cross-reactivity in immunoblots to the different recombinant cystatins. The purified rFgStefin-2 exhibited inhibitory activity against cysteine proteases (cathepsins B and L) and the proteolytic activity of ES product, CW extracts from metacercariae and adult parasites. We have demonstrated that FgStefin-2 is able to inhibit cysteine proteases (cathepsins B and L). In further analysis we would like to investigate the potential host-affecting functions such as immunomodulation.

Biography :

Sinee Siricoon has completed her PhD in Molecular Parasitology Unit and Graduate Program in Biomedical Sciences from Faculty of Allied Health Sciences, Thammasat University, Thailand. She has published 3 papers in reputed journals.

Email: vavajang6@hotmail.com