Interaction of Non-denatured Fibrilar Type I Collagen with some Micromolecular Compounds

摘要

Anionic surfactants and, especially sodium dodecyl sulphate, increases significantly viscosity of non-denatured fibrilar type I collagen gels in acid medium at low surfactant/collagen ratios. Dependence of viscosity at zero shearing rate on pH and collagen/surfactant ratio suggests that interaction is due to the electrostatic binding of surfactant anions on positively charged collagen and hydrophobic interaction of hydrocarbon tails of the anchored amphiphile anions. Rheological behaviour of systems containing cationic and nonionic surfactants supports the above mechanism: interaction with cationic surfactants occurs in acid medium, while with nonionic ones it is absent on the whole pH range. This is a confirmation of the primordial role of electrostatic forces and the secondary one played by the hydrogen bonds in this interaction. The influence of some additives which could affect such interactions (potassium chloride, ethyl alcohol, hydrogen breaker salts for water: potassium bromide, iodide, chlorate, and thiocyanale), as well as temperature and shearing rate on viscosity of collagen gels and collagen/sodium dodecyl sulphate systems confirms the above mechanism.