Patent ID: 7939083

Claim:
A purified, modified HIV-1 gp140 envelope polypeptide comprising (1) a gp120 polypeptide portion comprising consecutive amino acids and (2) a gp41 ectodomain polypeptide portion comprising consecutive amino acids, said gp41 ectodomain polypeptide portion being heterologous to the gp41 ectodomain polypeptide portion of a KNH1144 HIV-1 isolate and being modified to comprise isoleucine (I) at an amino acid position equivalent to amino acid position 535 (I535); glutamine (Q) at an amino acid position equivalent to amino acid position 543 (Q543); serine (S) at an amino acid position equivalent to amino acid position 553 (S553); lysine (K) at an amino acid position equivalent to amino acid position 567 (K567); and arginine (R) at an amino acid position equivalent to amino acid position 588 (R588), wherein the amino acid positions are numbered by reference to the KNH1144 HIV-1 isolate.