Figure 1.

Schematic structures of the human TFF peptides TFF1, TFF2, and TFF3. Cysteine residues (C; numbering in Roman numerals) as well as the free thiol groups at Cys^VII in TFF1 and TFF3 are shown in yellow. TFF2 contains an N-linked carbohydrate moiety and an additional disulfide bridge between Cys-6 and Cys-104, which creates a circular structure. Additionally outlined are the proline residues (P) at the C-terminal outside the TFF domains. Acidic residues close to the C-terminal cysteine residues are shown in blue.