Interaction of recombinant HAWW/WWHA proteins with Dd. (A) Interaction of denatured HA variants. Proteins were separated by SDS-PAGE, transferred to PVDF membrane and overlaid with the Dd solution. Vector bound to the membrane was detected with specific anti-Dd antibody. Lanes 1 to 6: WWHA_1 to WWHA_6, respectively. K - control HF cells, WW – fragment of Rsp5 protein, containing WW linker (positive control), BSA – bovine serum albumin (negative control). Fusions of HA with WW are denoted with a dot. (B) Interaction of non-denatured HA variants. Serial dilutions of HF cells expressing HAWW/WWHA variants were incubated with Dd and the recombinant proteins bound to the vector were detected with anti-HA antibody as described in Materials and Methods.