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Crystal structure of the neutralizing Llama V(HH) D7 and its mode of HIV-1 gp120 interaction.

Hinz A, Lutje Hulsik D, Forsman A, Koh WW, Belrhali H, Gorlani A, de Haard H, Weiss RA, Verrips T, Weissenhorn W - PLoS ONE (2010)

Bottom Line: Structural comparison of CDRs from other CD4 binding site antibodies suggests diverse modes of interaction.Mutational analysis identified CDR3 as a key component of gp120 interaction as determined by surface plasmon resonance.Furthermore, our data confirm that the structural plasticity of gp120 can accommodate multiple modes of antibody binding within the CD4 binding site.

View Article: PubMed Central - PubMed

Affiliation: Unit of Virus Host Cell Interactions (UVHCI), UMI 3265, Université Joseph Fourier-EMBL-CNRS, Grenoble, France.

ABSTRACT
HIV-1 entry into host cells is mediated by the sequential binding of the envelope glycoprotein gp120 to CD4 and a chemokine receptor. Antibodies binding to epitopes overlapping the CD4-binding site on gp120 are potent inhibitors of HIV entry, such as the llama heavy chain antibody fragment V(HH) D7, which has cross-clade neutralizing properties and competes with CD4 and mAb b12 for high affinity binding to gp120. We report the crystal structure of the D7 V(HH) at 1.5 A resolution, which reveals the molecular details of the complementarity determining regions (CDR) and substantial flexibility of CDR3 that could facilitate an induced fit interaction with gp120. Structural comparison of CDRs from other CD4 binding site antibodies suggests diverse modes of interaction. Mutational analysis identified CDR3 as a key component of gp120 interaction as determined by surface plasmon resonance. A decrease in affinity is directly coupled to the neutralization efficiency since mutations that decrease gp120 interaction increase the IC50 required for HIV-1 IIIB neutralization. Thus the structural study identifies the long CDR3 of D7 as the key determinant of interaction and HIV-1 neutralization. Furthermore, our data confirm that the structural plasticity of gp120 can accommodate multiple modes of antibody binding within the CD4 binding site.

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Related in: MedlinePlus

Comparison of CDR2 and CDR3 from D7, b12, b13, F105 and m18 indicates different modes of gp120 interaction.The Cα atoms of the heavy chain variable domains (b12 pdb code 2NY7; F105 pdb code 3HI1; b13 pdb code 3IDX; m18 pdb code 2AJ3) were superimposed and the CDR H2 and H3 are represented in the same orientation. Amino acids are labelled using the one letter code for clarity. (A) All CDR3 loops expose aromatic residues at their apex. (B) The CDR2 of D7 varies from CDR H2 of b12 indicating a different mode of gp120 interaction. Residues implicated in gp120 interaction are highlighted in orange.
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pone-0010482-g003: Comparison of CDR2 and CDR3 from D7, b12, b13, F105 and m18 indicates different modes of gp120 interaction.The Cα atoms of the heavy chain variable domains (b12 pdb code 2NY7; F105 pdb code 3HI1; b13 pdb code 3IDX; m18 pdb code 2AJ3) were superimposed and the CDR H2 and H3 are represented in the same orientation. Amino acids are labelled using the one letter code for clarity. (A) All CDR3 loops expose aromatic residues at their apex. (B) The CDR2 of D7 varies from CDR H2 of b12 indicating a different mode of gp120 interaction. Residues implicated in gp120 interaction are highlighted in orange.

Mentions: CD4 binding site antibodies b12, b13, F105 and m18 display a similar architecture of their CDR3 heavy chains with aromatic residues positioned at the apex of their CDR3 (Figure 3A). This feature led originally to the proposal that this class of antibodies employs aromatic CDR residues to fill the gp120 pocket that is occupied by Phe43 in the CD4- bound state [41], [45]. Although b12 and b13 point their CDR2 residue Tyr53 and Tyr52A, respectively, towards the CD4 binding pocket [14], mAb F105 employs CDR3 Phe100A and Tyr100B within the CD4 binding site [15].


Crystal structure of the neutralizing Llama V(HH) D7 and its mode of HIV-1 gp120 interaction.

Hinz A, Lutje Hulsik D, Forsman A, Koh WW, Belrhali H, Gorlani A, de Haard H, Weiss RA, Verrips T, Weissenhorn W - PLoS ONE (2010)

Comparison of CDR2 and CDR3 from D7, b12, b13, F105 and m18 indicates different modes of gp120 interaction.The Cα atoms of the heavy chain variable domains (b12 pdb code 2NY7; F105 pdb code 3HI1; b13 pdb code 3IDX; m18 pdb code 2AJ3) were superimposed and the CDR H2 and H3 are represented in the same orientation. Amino acids are labelled using the one letter code for clarity. (A) All CDR3 loops expose aromatic residues at their apex. (B) The CDR2 of D7 varies from CDR H2 of b12 indicating a different mode of gp120 interaction. Residues implicated in gp120 interaction are highlighted in orange.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2864739&req=5

pone-0010482-g003: Comparison of CDR2 and CDR3 from D7, b12, b13, F105 and m18 indicates different modes of gp120 interaction.The Cα atoms of the heavy chain variable domains (b12 pdb code 2NY7; F105 pdb code 3HI1; b13 pdb code 3IDX; m18 pdb code 2AJ3) were superimposed and the CDR H2 and H3 are represented in the same orientation. Amino acids are labelled using the one letter code for clarity. (A) All CDR3 loops expose aromatic residues at their apex. (B) The CDR2 of D7 varies from CDR H2 of b12 indicating a different mode of gp120 interaction. Residues implicated in gp120 interaction are highlighted in orange.
Mentions: CD4 binding site antibodies b12, b13, F105 and m18 display a similar architecture of their CDR3 heavy chains with aromatic residues positioned at the apex of their CDR3 (Figure 3A). This feature led originally to the proposal that this class of antibodies employs aromatic CDR residues to fill the gp120 pocket that is occupied by Phe43 in the CD4- bound state [41], [45]. Although b12 and b13 point their CDR2 residue Tyr53 and Tyr52A, respectively, towards the CD4 binding pocket [14], mAb F105 employs CDR3 Phe100A and Tyr100B within the CD4 binding site [15].

Bottom Line: Structural comparison of CDRs from other CD4 binding site antibodies suggests diverse modes of interaction.Mutational analysis identified CDR3 as a key component of gp120 interaction as determined by surface plasmon resonance.Furthermore, our data confirm that the structural plasticity of gp120 can accommodate multiple modes of antibody binding within the CD4 binding site.

View Article: PubMed Central - PubMed

Affiliation: Unit of Virus Host Cell Interactions (UVHCI), UMI 3265, Université Joseph Fourier-EMBL-CNRS, Grenoble, France.

ABSTRACT
HIV-1 entry into host cells is mediated by the sequential binding of the envelope glycoprotein gp120 to CD4 and a chemokine receptor. Antibodies binding to epitopes overlapping the CD4-binding site on gp120 are potent inhibitors of HIV entry, such as the llama heavy chain antibody fragment V(HH) D7, which has cross-clade neutralizing properties and competes with CD4 and mAb b12 for high affinity binding to gp120. We report the crystal structure of the D7 V(HH) at 1.5 A resolution, which reveals the molecular details of the complementarity determining regions (CDR) and substantial flexibility of CDR3 that could facilitate an induced fit interaction with gp120. Structural comparison of CDRs from other CD4 binding site antibodies suggests diverse modes of interaction. Mutational analysis identified CDR3 as a key component of gp120 interaction as determined by surface plasmon resonance. A decrease in affinity is directly coupled to the neutralization efficiency since mutations that decrease gp120 interaction increase the IC50 required for HIV-1 IIIB neutralization. Thus the structural study identifies the long CDR3 of D7 as the key determinant of interaction and HIV-1 neutralization. Furthermore, our data confirm that the structural plasticity of gp120 can accommodate multiple modes of antibody binding within the CD4 binding site.

Show MeSH
Related in: MedlinePlus