The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron micrsocopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.
FEDERAL FUNDING LEGEND
 This invention was supported, in part, by NIH grants P01 AI82362 and R01 AI36082 and an NIH-funded program (P30 AI036214), which is supported by the following NIH Institutes and Centers: NIAID, NCI, NIMH, NIDA, NICHD and NHLBI. The invention was also supported, in part, by NIH through the National Center for Research Resources' P41 program (RR017573) at the National Center for Research Resources, the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 and the U.S. Department of Energy, Basic Energy Sciences, Office of Science, under contract no. DE-AC02-06CH11357. The federal government may have certain rights to this invention.