Related Experiment Video
Updated: Dec 13, 2025

Microinjection for Transgenesis and Genome Editing in Threespine Sticklebacks
Published on: May 13, 2016
Grass carp (Ctenopharyngodon idella) stefin A: Systematic research on its cloning, expression, characterization and
Ran Li1, Shuhong Li2, Zhiguang Chen2
1College of Food Science, Sichuan Agricultural University, Sichuan Province 625014, China; Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki 00014, Finland.
Abstract:
To fully understand the properties of piscine stefins (family I cystatins), the 294-bp stefinA gene from grass carp (Ctenopharyngodon idella, Ci) was cloned and expressed in E. coli BL21 (DE3). After purification by Ni2+-NTA agarose affinity chromatography, the CiStefin A protein was tested to have a molecular weight of 11.48 kDa and an isoelectric point of 8.7. The typical motif of the cystatins superfamily was characterized from CiStefin A (QVVQG). CiStefin A specifically inhibited the activity of papain and cathepsin B/L. The Ki value of CiStefin A against papain was 6.5 × 10-11 M. CiStefin A showed excellent heat and acid-base tolerance. StefinA gene transcription occurred in all tested tissues of grass carp, with the highest level in the hepatopancreas. Immunolocalization staining with an anti-CiStefinA antibody revealed the CiStefinA protein distribution in all tested tissues at various levels. Overall, these results clarified the physical and biochemical properties of grass carp stefin A.

