Isolation and Purification of an Antimicrobial Protein from Rabbit Small Intestine and Its Antibacterial Activity

Objective To study the nature and composition of an antimicrobial protein isolated from the small intestine of rabbit.Methods After the small intestine tissue of rabbit was treated by homogenation,heating and acetic acid extraction,antimicrobial components were isolated from the intestinal tissue of rabbit by Sephadex G100 and Sephadex G75 gel filtration chromatography.The samples were analyzed by SDS polyacrylamide gel electrophoresis.The antibacterial activity of the extract against 9 strains of bacteria were tested by agarose diffusion assay and live bacteria counting assay.Results The results showed that an antimicrobial protein was obtained and purified.Its molecule weight was about 43×10~3.This antimicrobial protein strongly inhibited the 9 bacteria strains and the bacteria-killing rates varied from 78% to 98%.Conclusion An antimicrobial protein has been isolated and purified from the small intestine of rabbits.The strong inhibition effect of this protein on 9 bacteria strains indicates its promising potential application against bacterial diseases and it deserves further investigation.