Figure 2.

Amino acid sequences and NMR structure of ribbon GeXIVA and cyclic ribbon isomers of GeXIVA. A, amino acid sequences of ribbon GeXIVA and cyclic analogs. The backbone cyclization of ribbon GeXIVA was carried out using different sized linkers (highlighted in red) spanning its N and C termini (indicated by the black bracket and line). The black curved lines below the sequence show the ribbon disulfide connectivity. The α-carbon (Cα) RMSD of the backbone for the parent peptide and molecular models of the cyclic peptides are shown in the last column. B, NMR solution structure of ribbon GeXIVA (green) and models of cyclic variants (backbones in blue and linkers in red). The disulfide bonds are represented by yellow sticks, and the Cα are shown as balls.