Disulfide bond formation in NGR fiber-modified adenovirus is essential for retargeting to aminopeptidase N

• Published in: Biochemical and biophysical research communications Vol. 348; no. 1; pp. 278 - 287
• Main Authors: Majhen, Dragomira, Gabrilovac, Jelka, Eloit, Marc, Richardson, Jennifer, Ambriović-Ristov, Andreja
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.09.2006; Elsevier
• Subjects: Adenoviridae - metabolism; Adenovirus; Adenovirus type 5; Amino Acid Motifs; Amino Acid Sequence; Aminopeptidase N; Binding Sites; Biochemistry, Molecular Biology; Capsid Proteins - genetics; Capsid Proteins - metabolism; CD13 Antigens - metabolism; Cell Line; Cysteine; Disulfide bond; Disulfides; Gene Transfer Techniques; Genetic Vectors; Humans; Integrin alphaVbeta3 - metabolism; Integrin α vβ 3; Life Sciences; Molecular Sequence Data; NGR; Protein Binding; Retargeting; Substrate Specificity; Transduction, Genetic; Retargeting; NGR; Disulfide bond; Aminopeptidase N; Adenovirus type 5; Integrin α vβ 3; ADENOVIRUS TYPE 5; DISULFIDE BOND; INTEGRIN ALPHA(V)BETA; RETARGETING; AMINOPEPTIDASE N
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2006.07.051

The peptide motif NGR (asparagine–glycine–arginine) is known to bind to aminopepidase N (APN). We have constructed five adenoviruses (Ads) bearing NGR in the HI loop of the adenoviral fiber protein. We compared the targeting properties of the NGR peptide within different amino acid environments and showed that their cellular receptor(s) were not identical. Ads containing NGR within potentially cyclic sequences flanked by cysteines retargeted viruses mainly to APN, while Ads containing NGR within linear sequences not containing cysteines retargeted Ads mainly to α vβ 3 integrin, albeit with a lower affinity. Finally, we show evidence that disulfide bond formation within an Ad bearing the CDCNGRCFC sequence is essential for retargeting to APN, suggesting that this sequence does indeed assume a cyclic structure which facilitates NGR binding to APN. Therefore, our study underscores the importance of cysteine residues flanking targeting peptides for not only affinity but also specificity of the retargeted Ad.