Patent ID: 7048929

Claim:
A modified gp120 polypeptide comprising portions of at least two conserved regions of an envelope protein selected from a the group of lentiviruses consisting of HV-1, HIV-2 and SIV, wherein at least one of the following changes relative to the wild-type gp120 protein is made: (a) introduction of disulfide bonds to decrease the free energy of folding relative to the wild type gp120 protein; (b) filling a cavity of the gp120 protein with hydrophobic amino acid residues; or (c) introducing a Pro residue at a defined turn structure; wherein the modified polypeptide maintains the overall 3-dimensional structure of a discontinuous conserved epitope of the wild-type gp120, wherein the discontinuous conserved epitope is a CD4BS epitope, CD4i epitope or 2G12 epitope.