Abstract: ObjectiveTo 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.MethodsOverlapping 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.ResultsA recombinant expression vector pFUSE/N51Fd-BC
was successfully constructed. N51FdFc-BC recombinant protein with a relative molecular mass of about35000was effectively
expressed in mammalian293T cells and could be recognized by rabbit antibodies against HIV-1gp41N/C peptides as shown
by Western blotting. Bioinformatic analysis showed that the recombinant protein N51FdFc-BC, with a relative molecular mass
of34315.1and a PI of7.59, 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.ConclusionThe recombinant
protein N51FdFc-BC has a random coil structure and can be used as an immunogen for development of HIV-1subunit vaccine.