Study On The Isolation And Purification Of Antimicrobial Protein From Rabbit Small Intestine And Its Biological Activity

To develop an antimicrobial protein from rabbit small intestine,After the small intestine tissue of rabbit was treated by homogenation, heating and acetic acid extraction, An antimicrobial protein were isolated from the intestinal tissue of rabbit after purification,After the initial study of an Antimicrobial protein from rabbit small intestine antibacterial activity and anti-virus activity and the comparative study on the antibacterial activity of the extraction from the small intestine of rabbit and antibiotic, The results show that the extraction from the small intestine of rabbit can replace the antibiotic to cure some antibacterial diseases and virus disease. The reseach divide three parts:Part One:Study on the isolation and purification of an antimicrobial protein from rabbit small intestine and its antibacterial activityTo study the nature and the composition of an antimicrobial protein from the small intestine of rabbits. 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. The results showed that an antimicrobial protein was obtained and purified. Its molecule weight was about 43×103. This antimicrobial protein strongly inhibited the 9 bacteria strains and the bacteria-killing rates varied from 78% to 98%. 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.Part Two:The comparative study on the antibacterial activity of the extraction from the small intestine of rabbit and antibioticTo determine the ration of antimicrobial ingredients from the small intestine of rabbit, After the small intestines of rabbit were treated by pulper, heating and acetic acid extraction. The activities of the antimicrobial ingredients and familiar antibiotic ( Penicillin, Gentamycin Sulfate, Ciprofloxacin, Erythromycin, Amikacin, Sulfamethoxazole )against four strains ( Escherichia coli 8099, Staphylococcus aureus ATCC6538, Pseudomonas aeruginosa ATCC9027,Staphylococcus albus 8032)of bacteria were tested by agarose diffusion assay .The result showed that the activities of the antimicrobial ingredients have different antibiotic activitie unit of different antibiotic.The activities of the antimicrobial ingredients were higher or equal to the density 50mg/mL Sulfame thoxazole solution.The results show that the extraction from the small intestine of rabbit can replace the antibiotic to cure some antibacterial diseases, the application of extraction from the small intestine of rabbit in the medicine has a bright prospect.Part Three:The initial study of an antimicrobial protein from rabbit small intestine against virus Treated the Newcastle disease virus(NDV) and Infectious bronchitis virus(IBV) with ABP, then inoculate them into chicken embryo ,then measured the erythrocyte agglutination titer of NDV in chicken embryo allantoic fluids, and observe. the pathological changes of chicken embryo. The result showed that the erythrocyte agglutination titer of NDV was lower than controlled series, and the pathological changes were less serious than controlled series, indicate that ABP can inhibit the pathological changes of chicken embryo caused by NDV and 1BV.On the whole, through these studies, we isolated and purified the ABP from the small intestine of rabbit, revealed its antibacterial and antivirus activity, and its effect on immune function of chicken. Indicated its prospect as antibacterial and antivirus drugs or as immunomodulator.