A buried polar residue in the hydrophobic interface of the coiled-coil peptide, GCN4-p1, plays a thermodynamic, not a kinetic role in folding.

The hydrophobic interfaces of coiled-coil proteins and peptides are typically interspersed with buried polar residues. These polar residues are known to be important for defining oligomeric specificity and chain orientation in coiled-coil formation; however, their effects on the folding/assembly reaction have not been investigated. The commonly studied 33-residue dimeric leucine zipper peptide, GCN4-p1, contains a single polar Asn in the center of the hydrophobic interface at position 16.