A single amino acid in the adenovirus type 37 fiber confers binding to human conjunctival cells

A 46-kDa receptor, coxsackievirus-adenovirus (Ad) receptor (CAR), mediates cell attachment of a number of different Ad serotypes; however, not all Ad serotypes utilize this receptor for infection. Moreover, the precise amino acid sequences in the Ad fiber protein that mediate cell attachment have ye t to be identified. We investigated the interaction of subgroup D Ads with human ocular cells. Ad serotype 37 (Ad37), a virus associated with epidemic keratoconjunctivitis, but not a closely related virus serotype, Ad19p, exh ibited preferential binding to and infection of human conjunctival cells, A single amino acid substitution in the Ad19p fiber distal domain (knob), Gl u(240) to Lys, conferred binding to conjunctival cells, while the reverse s ubstitution in the Ad37 fiber abrogated cell binding. These findings provid e new information on the fiber sequences that regulate Ad host cell tropism .