Recombinant Sulfated HIV Envelope Protein and Methods for Making Protein

This technology comprises sulfated recombinant gp120 proteins and peptides. Also included are methods for producing sulfated recombinant gp120 proteins. The focus of this technology is on sulfation of two tyrosines in the V2 loop of the HIV major envelope glycoprotein, gp120, which increase the stability of gp120 and promote the synthesis of gp120 protein in its native "closed" conformation. Gp120 in its native form is highly sulfated; however, recombinant gp120 produced for vaccines or structural analyses typically display low levels of V2 tyrosine sulfation. Sulfation of the V2 loop results in increased binding to trimer-recognizing anti-HIV antibodies specific to the V2 loop region of gp120 (PG9, PG16, CH01, PGT145) and decreased binding of CD4. The sulfation of recombinant gp120 is accomplished by over expression of a tyrosyl sulfotransferase in the producing cell line. Preliminary experiments indicate the recombinant sulfated gp120 proteins can be used to elicit the formation of HIV neutralizing antibodies in immunized animals.