%0 Journal Article %T CD4 occupancy triggers sequential pre-fusion conformational states of the HIV-1 envelope trimer with relevance for broadly neutralizing antibody activity %A Alexandra Trkola %A Branislav Ivan %A Harini Subbaraman %A Nikolas Friedrich %A Zhaozhi Sun %J Archive of "PLoS Biology". %D 2019 %R 10.1371/journal.pbio.3000114 %U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6351000/