Ferrocene-assisted stabilization of collagen mimetic triple helices: solid-phase synthesis and structure

A series of ferrocene-containing collagen models Fc-CO-(Pro-Hyp-Gly)n-Cys (n = 4 (1), 6 (2), 7 (3), 8 (4), 9 (5)) were synthesized by solid-phase synthesis. Biophysical studies using circular dichroism (CD) show that these collagen analogues form triple-helical conformations, and the peptides showed a range of thermal stabilities ((T(m)), 38-74 degrees C). Results also indicate that the ferrocene (Fc)-labeled collagen models possesses a higher triple-helical propensity than the unlabeled collagen models as demonstrated by the higher melting temperatures and thermodynamic parameters, and we conclude that the Fc group at the N-terminal position of the peptide strands increases the stability of the triple helix.