Truncated variants of gp120 bind CD4 with high affinity and suggest a minimum CD4 binding region.

AUTOR(ES)

Pollard, S R

RESUMO

The envelope glycoprotein, gp120, of human immunodeficiency virus type 1 (HIV-1) binds the cellular protein CD4 with high affinity. By deletion we show that 62 N- and 20 C-terminal residues along with the V1, V2 and V3 variable regions of gp 120 are unnecessary for CD4 binding. A 287 residue variant (ENV59), missing those 197 amino acids, binds to CD4 with high affinity. A polyclonal antibody failed to efficiently precipitate ENV59 which is consistent with the loss of immunodominant antigenic structures in the regions deleted. This suggests that ENV59 may have potential as an immunogen, able to elicit antibodies against more conserved regions of gp120. Additionally, complementing co-expressed gp120 fragments as well as a circularly permuted molecule bind CD4, and suggest either that the molecular termini are adjacent in the folded structure, or that an N-terminal region folds into the structure unconstrained by its method of attachment to the rest of the molecule.

Documentos Relacionados

• Recombinant CD4-selected human immunodeficiency virus type 1 variants with reduced gp120 affinity for CD4 and increased cell fusion capacity.
• Rapid Progression to Simian AIDS Can Be Accompanied by Selection of CD4-Independent gp120 Variants with Impaired Ability To Bind CD4
• Inhibition of Human Immunodeficiency Virus Type 1 gp120 Presentation to CD4 T Cells by Antibodies Specific for the CD4 Binding Domain of gp120
• Relationship of the human immunodeficiency virus type 1 gp120 third variable loop to a component of the CD4 binding site in the fourth conserved region.
• Cyanovirin-N Binds to gp120 To Interfere with CD4-Dependent Human Immunodeficiency Virus Type 1 Virion Binding, Fusion, and Infectivity but Does Not Affect the CD4 Binding Site on gp120 or Soluble CD4-Induced Conformational Changes in gp120†