Targeting adenovirus with use of constrained peptide motifs

The chimeric adenovirus fiber protein comprising a nonnative amino acid sequence, wherein said nonnative amino acid sequence is constrained in a loop comprising a set of amino acid residues selected from the group consisting of residues 403-418, 441-453, 487-514, 522-528, 537-549, and 558-572.

A chimeric adenovirus fiber protein comprising a nonnative amino acid sequence, wherein said nonnative amino acid sequence is constrained by being inserted into or in place of a loop selected from the group consisting of the AB, CD, DG, GH, HI, and IJ loops of said chimeric adenovirus fiber protein.

A method of increasing the affinity of a peptide for a cell surface binding site which comprises:

• (a) obtaining a wild-type adenovirus fiber protein, and
• (b) inserting into or in place of a protein sequence in a loop of said knob of said wild-type adenovirus fiber protein a nonnative amino acid sequence so as to result in a chimeric adenovirus fiber protein.

A method of increasing the affinity of a RGD sequence for a cell surface binding site which comprises:

• (a) obtaining a wild-type adenovirus fiber protein, and
• (b) inserting a RGD sequence into or in place of a protein sequence of said wild-type adenovirus fiber protein such that it is flanked by one or more cysteine pairs and is capable of forming a loop due to interaction between said cysteines.