Fig. 3.

Medium from HCMV-infected cultures contains RANTES-binding activity. (A) Crosslinking assay demonstrating pUL21.5 chemokine-binding activity. Concentrated protein preparations from the medium of mock-, ADwt (wt)-, and ADsubUL21.5 (subUL21.5)-infected cultures were incubated with ¹²⁵I-RANTES, MIP-1α, and IL-8. The mixtures were treated at room temperature for 30 min with the crosslinking agent EDC (40 mM), and the resulting crosslinked complexes were analyzed by electrophoresis in SDS-containing polyacrylamide gels. Size markers are identified by their molecular masses (kDa). (B) Chemokine binding specificity of pUL21.5. Concentrated protein from the medium of ADwt-infected infected cultures was incubated with ¹²⁵I-RANTES in the presence of unlabeled RANTES, MIP-1α, or MCP-1, the mixtures were treated with EDC, and the resulting crosslinked complexes were analyzed by electrophoresis. The fold-excess of unlabeled ligand is indicated above each lane. Size markers are identified by their molecular masses (kDa).