New Index for the Stability of a Type I Collagen Affected by Hydrophobic Environment

Abstract

Effects of hydrophobic environment adjusted by various alcohols on the structural stability of calfskin collagen (CSC) were studied to elucidate the nature of collagen-monomer interaction in adhesion. The stability of CSC in aqueous alcohol solutions was represented by its denaturation temperature, Td, measured by DSC. The hydrophobicity of the alcohol solutions was quantified with their specific dielectric constants, εr, calculated from their concentrations. The effect of each alcohol to stabilize or destabilize CSC was evaluated by the initial slope of each Td vs. εr plot, denoted as -(dTd/dεr)ini and termed as stabilization power. Results showed that a hydrophobic environment with a smaller εr lowered the stabilization power. Stabilization power ranged from -3 (strong destabilization) for phenol (εr＝12) to ＋0.3 (weak stabilization) for glycerol (εr＝47). In view of the encouraging results obtained in this study, the new index was therefore helpful in predicting the effects of new dental materials of known εr values on the stability of dentinal collagen.

Factors affecting thermal stability of collagen from the aspects of extraction, processing and modification

“…Aliphatic alcohols could promote the solubility of hydrophobic residues of collagen into the solvent medium to weaken hydrophobic bonds, thus destabilizing the triple helix [158,159]. The effect of monohydric alcohols with different specific dielectric constant (Ɛr) on the collagen was reported by Nezu et al [160]. Water has the Ɛr value of above 80 and many organic compounds have smaller Ɛr values.…”