Isolation, purification and anti-bacterial property of calprotectin from bovine neutrophil

It is believed that bovine neutrophils contain several peptides and protein which exhibit antimicrobial activity against microorganisms such as fungi and bacteria.
The purpose of this study was to isolate and purify a potential antibacterial protein from bovine neutrophil and test its anti bacterial activity.
Neutrophils were isolated from bovine blood using dextran sedimentation and centrifugation on Ficoll-Hypaqe. Cell viability is examined by trypan blue dye exclusion method. Protein extract was then dialyzed and applied onto ion exchange chromatography for further purification, and its potential cytostatic activity was examined against Staphylococcus aureus, Aeromonas hydrophila and Yersinia ruckeri.
Viability of isolated neutrophil was over 95%, chromatographic results and SDS-PAGE analysis exhibited that neutrophil cytosolic proteins were fractionated so that the purification of P7/P23 was almost 60% in the first step and purification was completed in the second phase. Using calibration curve according to molecular mass markers, the relative molecular mass of P7 and P23 determined as 7 kDa and 23 kDa, respectively. Also, results showed that this protein has antibacterial activity and has higher bactericidal activity against Y. ruckeri.
It could be concluded that purification of P7/P23 sustains its biological activity and has wide range antibacterial activity. Moreover, taking all data into account may suggest that the cytostatic activity of neutrophil, to some extent, results from P7/P23 protein which is abundant in the cytosole.