Intact Transition Epitope Mapping - Forces of Interactions between Variants of Equivalent macromolecules (ITEM-FIVE)

Foldon (F) is a specific partial sequence from the C-terminal domain of T4 fibritin, which is found at the neck of the T4 bacteriophage. The amino acid sequence (27 residues) in single letter code is GYIPEAPRDGQAYVRKDGEWVLLSTFL. In neutral solution (pH 6.9) it forms a homo-trimer (F-F-F). Biotinylated foldon (bF) is composed of the exact same amino acid sequence but contains a biotin residue attached to the N-terminal amino acid residue via two PEG linker molecules. In solution with neutral pH it forms a homo-trimer (bF-bF-bF). Mixing of both homo-trimers in solution with neutral pH spontaneously produces hetero-trimers (F-F-bF and F-bF-bF).