Fig. 6

AAT and C directly interacted with gp41. HIV-1_NL4.3 was incubated in the presence or absence of AAT/ΔAAT and then concentrated by ultracentrifugation (100,000 × g for 2 h at 4 °C) to extract viral proteins. AAT antibody was then added to viral proteins to precipitate proteins interacting with AAT/ΔAAT. Next, each specific protein was identified by peptide mass fingerprinting assay (a). Meanwhile, after concentrating, the virus was also divided into two aliquots. One aliquot was lysed to extract whole viral proteins and AAT antibody was then added to precipitate the proteins interacting with AAT/ΔAAT. AAT, gp120 or gp41 in the precipitated proteins were detected by immunoblotting (b). The other aliquot was incubated with gp120 antibody to precipitate proteins interacting with viral particles. Subsequently, precipitated viruses were lysed to detect AAT, gp120 and gp41 by Immunoblotting (c). Moreover, AAT/C/ΔAAT was also cultured with gp120 or gp41. Next, gp120 or gp41 antibody was added to precipitate. The direct interaction between AAT/C/ΔAAT and gp120/gp41 was determined by separating precipitated proteins with SDS-PAGE and proteins were visualized by Coomassie blue staining (d). MW: molecular weight marker; IP: immunoprecipitation; WB: western blotting (immunoblotting)