Selection of high affinity ligands to hepatitis B core antigen from a phage-displayed cyclic peptide library.

• Main Authors: Ho, Kok Lian, Yusoff, Khatijah, Seow, Heng Fong, Tan, Wen Siang
• Format: Article
• Language: English; English; English
• Published: Wiley-blackwell 2003
• Subjects: Hepatitis associated antigen.; Peptides - Physiological effect.
• Online Access: http://psasir.upm.edu.my/id/eprint/16650/1/Selection%20of%20high%20affinity%20ligands%20to%20hepatitis%20B%20core%20antigen%20from%20a%20phage.pdf; http://psasir.upm.edu.my/id/eprint/16650/7/Journal%20of%20Medical%20Virology%20-%202002%20-%20Ho%20-%20Selection%20of%20high%20affinity%20ligands%20to%20hepatitis%20B%20core%20antigen%20from%20a.pdf; http://psasir.upm.edu.my/id/eprint/16650/; http://as.wiley.com/WileyCDA/Brand/id-35.html

M13 phages that display random disulfide constrained heptapeptides on their gpIII proteins were used to select for high affinity ligands to hepatitis B core antigen (HBcAg). Phages bearing the amino acid sequences C-WSFFSNI-C and C-WPFWGPW-C were isolated, and a binding assay in solution showed that these phages bind tightly to full-length and truncated HBcAg with KDrel values less than 25 nM, which is at least 10 orders of magnitude higher than phage carrying the peptide sequence LLGRMK selected from a linear peptide library. Both the phages that display the constrained peptides were inhibited from binding to HBcAg particles by a monoclonal antibody that binds specifically to the immunodominant region of the particles. A synthetic heptapeptide with the amino acid sequence WSFFSNI derived from one of the fusion peptides inhibits the binding of large surface antigen (L-HBsAg) to core particles with an IC50 value of 12 ± 2 μM. This study has identified a smaller peptide with a greater inhibitory effect on L-HBsAg-HBcAg association.