Analysis of Ad3 fiber knob binding to soluble CD46. Ad3 fiber knobs containing different numbers of shaft motifs and either the wild-type Ad3 fiber knob (lane 1, Ad3-S6/Kn; lane 2, Ad3-S5/Kn; lane 3, Ad3-S4/Kn; lane 4, Ad3-S3/Kn; lane 5, Ad3-S2/Kn; lane 6, Ad3-S/Kn), JO-1 (lane 7) or the CD46-binding Ad35 fiber knob (lane 8) were blotted and hybridized with soluble DSG2 (upper) or soluble CD46 (lower). Binding was detected by anti-DSG2 MAb or anti-CD46 MAb.