FIG. 5.

Requirement for GAG binding in sNec1₁₂₃-mediated infection. (A) Heparin inhibition of sNec1₁₂₃-mediated virus entry. Different dilutions of QOZHG were preincubated with or without 25 μg/ml heparin for 1 h at 4°C and incubated with CHO-K1 cells in suspension for 30 min at 4°C prior to the addition of 450 nM sNec1₁₂₃ and infection for 1 h at 37°C. The cells were plated with fresh medium, and entry was measured by ONPG assay the next day. Data represent the averages of triplicate determinations. (B) Heparin inhibition of infection via cellular nectin-1. QOZHG was preincubated with heparin as above and adsorbed to CHO-Nec1 cells. Infection was as described above without added sNec1₁₂₃ protein. The cells were processed for ONPG assay as above. (C) Infection of GAG-deficient CHO cells. CHO-K1 and GAG-deficient pgsD-677 and pgsA-745 cells were infected with QOZHG at an MOI of 3 in the presence (black bars) or absence (gray bars) of 450 nM sNec1₁₂₃ protein. Virus entry was determined by ONPG assay. Values are averages from triplicate infections.