Antimicrobial activity of chicken egg white cystatin

Abstract

The cysteine protease inhibitor cystatin was purified from chicken egg white and its antimicrobial activity determined for a series of pathogenic bacteria. The results indicate that Acinetobacter lwoffii, Escherichia coli, Oligella sp. and Pseudomonas aeruginosa are highly sensitive to low concentrations of cystatin, which possesses bactericidal activity. No inhibition was observed with a Citrobacter freundii strain. Fifty percent growth inhibition (IC 50 ) was observed at cystatin concentrations in the range of 80 and 100 lg/ml, and the growth was completely inhibited at concentrations in the range of 100 and 200 lg/ml. Fifty percent growth inhibition (IC 50 ) for Staphylococcus aureus, Staphylococcus gallinarum, and Staphylococcus xylosus strains was observed at 150 and 200 lg of cystatin/ml respectively, and growth was completely inhibited at cystatin concentrations in the range of 300 and 1000 lg/ml. The activity of cysteine proteases was significantly decreased in the culture supernatant of microorganisms when chicken cystatin was added. In this study, we observed that chicken cystatin may be a candidate for antibacterial drug development aiming at controlling bacterial pathogens including Escherichia coli, Pseudomonas aeruginosa, and another possible application might be as a therapeutic agent for health improvement.

In Vitro Antibacterial Activity of Cysteine Protease Inhibitor from Kiwifruit (Actinidia deliciosa)

“…This observation could potentially shed light on the mechanisms of inhibition. As previously described, egg cystatin reveals inhibitory activity towards secretory cysteine proteases from fermentation media of different gram negative bacteria, and effectively inhibits their growth [24]. Detection of CPI in bacterial growth media by dot blot analysis suggests that it might inhibit bacterial growth by inhibiting extracellular cysteine proteases.…”

Molecular Cloning and Characterization of Cystatin, a Cysteine Protease Inhibitor, fromBufo melanostictus

“…26) Cystatin as a tumor suppressor has been confirmed by observations of breast, prostate, and esophageal tumors. It inhibits tumor cell growth, angiogenesis, invasion, and metastasis.…”

Application of Microbial Proteases to Obtain Egg Yolk Protein Hydrolysates With Antioxidant and Antimicrobial Activity

“…The antimicrobial activity was determined by a modified method based on the diffusion test with filter discs [26]. Statistical analysis.…”