Partial characterization of a 17 kDa protein of Clonorchis sinensis

Abstract

A 17 kDa protein from Clonorchis sinensis adults was purified by a procedure including Sephacryl S-200 HR gel filtration and Q-Sepharose anion exchange chromatography. The protein was proved to be a cysteine protease as it showed hydrolytic activity toward Cbz-Phe-Arg-AMC in the presence of dithiothreitol and was inhibited by specific inhibitors such as iodoacetic acid or trans epoxy-succinly-L-leucyl-amido(4-guanidino) butane. The polyclonal antibody raised against the protein reacted to 17 kDa proteins of trematodes such as Paragonimus westermani, Fasciola hepatica, Opisthorchis viverrini, Gymnophalloides seoi, and Metagonimus yokogawai. The antibody recognized the 17 kDa and 16 kDa cysteine proteases purified from C. sinensis, P. westermani, and G. seoi as well. These results suggest that the 17 kDa protein may be a cysteine protease commonly present in trematodes.

Fig. 1

Purification of a 17 kDa protein bands of Clonorchis sinensis analyzed by 7.5-15% SDS-PAGE. 1, Crude extracts; 2, purified 17 kDa protein. Molecular weight in kDa is indicated.

Fig. 2

Common presence of a 17 kDa protein in different trematode parasites analyzed by immunoblotting. 1, metacerarial extracts of C. sinensis; 2, crude extracts of C. sinensis; 3, crude extracts of O. viverrini; 4, crude extracts of F. hepatica; 5, crude extracts of P. westermani; 6, crude extracts of G. seoi; 7, crude extracts of M. yokogawai; 8, crude extracts of S. japonicum; 9, sparganum crude extracts; 10, crude extracts of N. brasiliensis.