China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (2): 674-683.doi: 10.16431/j.cnki.1671-7236.2023.02.025

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Prokaryotic Expression and Immunoreactivity of PA-LF1 Fusion Protein of Bacillus anthracis

LYU Shuangfei1, MA Xun1, WANG Jing1, KONG Cuilian1, KOU Lijun1, LIU Caixia1, SHI Weidi1, KANG Lichao2, REN Huijie1   

  1. 1. College of Animal Science and Technology, Shihezi University, Shihezi 832000, China;
    2. Institute of Agricultural Quality Standards and Testing Technology, Xinjiang Academy of Agricultural Sciences, Shihezi 832000, China
  • Received:2022-08-31 Online:2023-02-05 Published:2023-02-06

Abstract: 【Objective】 The purpose of this experiment was to construct the PA-LF1 fusion gene expression vector of Bacillus anthracis (B. anthracis) attenuated C40-202 strain and to detect its prokaryotic expression and regenicity,so as to provide the basis for the preparation of anthrax subunit vaccine,the diagnosis of anthrax and the detection of vaccine immune effect.【Method】 Two pairs of primers were designed based on the sequences of B. anthracis PA and LF genes in GenBank,and the PA and LF1 gene fragments were amplified from B. anthracis weakly virulent strain C40-202 by PCR.After digestion by Xho Ⅰ restriction endonuclease,the PA-LF1 fusion gene fragment was obtained by connecting the sticky ends.SWISS-MODEL analysis software was used to predict the tertiary structures of PA,LF1 and PA-LF1 fusion proteins respectively.The fusion fragments were cloned into pET32a(+) plasmid to construct recombinant plasmid pET32a-PA-LF1,and the recombinant plasmid pET32a-PA-LF1 was transferred into E.coli BL21(DE3) competent cells for induced expression.SDS-PAGE was used to analyze the expression of the recombinant protein,and Western blotting was used to identify the fusion protein and analyze its reactogenicity.【Result】 PA, LF1 and PA-LF1 fusion genes were successfully amplified from B. anthracis weakly virulent strain C40-202.The B. anthracis PA-LF1 fusion gene expression plasmid pET32a-PA-LF1 was successfully constructed,and the tertiary structure of the fusion protein was predicted to fold to the correct spatial conformation.The recombinant plasmid was induced,purified and detected by SDS-PAGE,and the fusion protein with molecular weight of 96 ku was obtained.Western blotting showed that the purified recombinant protein had specific binding with the sheep serum immunized with anthrax spore vaccine Ⅱ,indicating that it had good reactivity.【Conclusion】 The PA-LF1 fusion protein had good reactogenicity and could provide a theoretical basis for anthrax diagnosis and vaccine immunity testing,and also could be used as a candidate component for an anthrax subunit vaccine.

Key words: Bacillus anthracis; PA-LF1 gene; clone; prokaryotic expression

CLC Number: