Journal of Jilin University Medicine Edition ›› 2015, Vol. 41 ›› Issue (02): 269-274.doi: 10.13481/j.1671-587x.20150212

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Fusion expression of Staphylococcus aureus IsdB epitope protein and HBc protein

BAI Liang1, CHENG Yan2, XU Fangfei3, LIU Yan1, ZHANG Shujun1, CAO Ruizhen1   

  1. 1. Department of Biochemistry and Molecular Biology, School of Life Science, Inner Mongolia University for Nationalities, Tongliao 028000, China;
    2. Department of Immunology and Microbiology, School of Medical Sciences, Inner Mongolia University for Nationalities, Tongliao 028000, China;
    3. Ji'an Yisheng Pharmaceutical Co.Ltd., Jilin Provice, Ji'an 134200, China
  • Received:2014-11-24 Online:2015-03-28 Published:2015-04-04

Abstract:

Objective To construct the E.coli expressiom system of the HBc-IsdB50-285 fusion protein, and to explore the expression efficacy of the HBc-IsdB50-285 fusion protein in prokaryotic system.Methods HBc-IsdB50-285 fusion gene fragment was designed and cloned,and the expression vector pET-28-HBc-IsdB50-285 was construct and transformed into E.coli BL21,the expression of protein was inducted by IPTG. The solubility of protein and its relative molecular mass were analyzed by SDS-PAGE method; BCA assay was used to detect the level of protein; the immune activity of the recombinant protein was detected by immune inoculation method.40 mice were divided into rIsdB+adjuvant group(n=10), HBc-IsdB50-285+adjuvant group(n=10), HBc-IsdB50-285 group(n=10), and PBS group(n=10).The values of special IgG of the mice were tested by ELISA method. The mice were immunized and attacked by Stathylococcus aureus Newman strain,and the immune protection rate of the recombinant protein was detected.Results The expression vector pET-28-HBc-IsdB50-285 was successfully constructed through identification of sequencing and restriction enzyme digestion. The SDS-PAGE results showed that the recombinant protein existed in a soluble form in the supernatant with relative molecular mass about 44 000.The level of purificated protein was 1.0 g·L-1.The ELISA results showed that the value of antibody titer of the mice in HBc-IsdB50-285+adjuvant group was lower than that in rIsdB+adjuvant group when the rIsdB were regarded as coating antigen(P<0.01);the values of antibody titer of the mice in HBc-IsdB50-285+adjuvant group was higer than those in rIsdB+adjuvant group and HBc-IsdB50-285 group when the HBc-IsdB50-285 were regarded as coating antigen(P<0.05);the attack test results showed that the protection rate of Staphylococcus aureus of the mice in HBC-IsdB50-285+adjuvant group was lower than that in rIsdB+adjuvant group (P>0.05). Compared with HBc-IsdB50-285 group, the protection rate of Staphylococcus aureus of the mice in HBC-IsdB50-285+adjuvant group had no significant difference (P>0.05). Compared with PBS group, the protection rates of Staphylococcus aureus of the mice in HBc-IsdB50-285+adjuvant group(P<0.01) and HBc-IsdB50-285 group(P<0.05) were increased.Conclusion A prokaryotic expression vector of HBC-IsdB50-285 is constructed, and the HBC-IsdB50-285 fusion protein with better biological activities is expressed in E.coli BL21 successfully.

Key words: Staphylococcus aureus, hepatitis B virus core protein, iron-regulated surface determinant B, epitope

CLC Number: 

  • R378.1