DAO 32:41-48 (1998)  -  doi:10.3354/dao032041

Characterization of a 200 kDa glycoprotein (Cs-gp200) on the pathogenic piscine haemoflagellate Cryptobia salmositica

Shujuan Feng, Patrick T. K. Woo*

Department of Zoology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
*Addressee for reprints requests. E-mail:

The 200 kDa antigenic doublet of the pathogenic haemoflagellate Cryptobia salmositica Katz, 1951, was detected using a monoclonal antibody (MAb-001) in 1-dimensional SDS-PAGE. This antigenic doublet is a glycoprotein since it was susceptible to both protease K and to sodium m-periodate oxidation and is designated Cs-gp200. It has a PI (isoelectric point) value of about 5.5 (using 2-dimensional gel electrophoresis). It migrated faster under reducing conditions than under non-reducing conditions and was partitioned into the aqueous phase in Triton X-114 phase separation. It is a secretory-excretory product since it was detected in a non-protein culture medium with C. salmositica. These results suggest that the Cs-gp200 is a glycoprotein consisting of carbohydrate determinants and conformational polypeptide with internal disulphide bonds. It is a hydrophilic antigen, is a secretory product of the parasite, and plays a important role in antibody elicitation in immunized fish.

Cryptobia salmositica · Haemoflagellate · Monoclonal antibody · Antigen · Glycoprotein

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