Construction and Characterization of Insect Cell-Derived Influenza VLP: Cell Binding, Fusion, and EGFP Incorporation

Figure 4

Conformational change of HA on VLPs triggered by low pH. The dissociation constant of mAb IIF4 with HA⁺ VLPs or HA⁻ VLPs at neutral or acidic pH was determined by SPR technique: (a) mAb IIF4 bound to HA⁺ VLPs at pH 7.4; (b) mAb IIF4 bound to HA⁺ VLPs at pH 5.0; (c) mAb IIF4 bound to HA^- VLPs at pH 5.0. (d) displays immunofluorescence staining of VLP by mAb IIF4. See “Materials and Methods” for details.

(a)

(b)

(c)

(d)