title: [Expression, structure and antigenicity analysis of N51 derived from the N-terminal heptad repeat domain in gp41 of HIV-1 CRF07_BC strain].
abstract: OBJECTIVE
  To express N51 derived from the N-terminal heptad repeat (NHR) domain in gp41 of the HIV-1 CRF07_BC strain and analyze its molecular structure and antigenicity.
  
  
  METHODS
  Overlapping PCR was used to amplify the DNA fragment encoding N51Fd gene, which was then subcloned into the vector pFUSE-hIgG1-Fc2. The construct was confirmed by DNA sequencing. The structure and antigenicity of the recombinant protein N51FdFc-BC were analyzed using bioinformatic software, circular dichroism, and Western blotting.
  
  
  RESULTS
  A recombinant expression vector pFUSE/N51Fd-BC was successfully constructed. N51FdFc-BC recombinant protein with a relative molecular mass of about 35 000 was effectively expressed in mammalian 293T cells and could  be recognized by rabbit antibodies against HIV-1 gp41 N/C peptides as shown by Western blotting. Bioinformatic analysis showed that the recombinant protein N51FdFc-BC, with a relative molecular mass of 34 315.1 and a PI of 7.59, formed a secondary structure of random coil to allow its interactions as an antigen with antibodies. Circular dichroism measurement confirmed the random coil structure of N51FdFc-BC protein.
  
  
  CONCLUSIONS
  The recombinant protein N51FdFc-BC has a random coil structure and can be used as an immunogen for development of HIV-1 subunit vaccine.
authors.affiliation: School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China. jpshaosl@163.com
authors.forename: Jiping
authors.initials: J
authors.lastname: Shao
authors.forename: Shibo
authors.initials: S
authors.lastname: Jiang
authors.forename: Shuwen
authors.initials: S
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D057809:HEK293 Cells; D015700:HIV Envelope Protein gp41 / Q000235:genetics* / Q000276:immunology*; D015497:HIV-1 / Q000737:chemistry* / Q000235:genetics*; D006801:Humans; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D017422:Sequence Analysis, DNA
chemical_list: D015700:HIV Envelope Protein gp41; D011994:Recombinant Proteins