title: Intermolecular interaction studies on native and enzyme-treated acid-soluble collagen.
abstract: The aggregative properties of acid-soluble collagen, native or enzyme treated, have been studied by electric birefringence and low shear rate viscosity. A unique type of aggregate has been found, about 700 nm long for native collagen and 530 nm for pepsin treated, regardless of the acetic acid concentration in the range 1--100 mM. The number of aggregates increases with collagen concentrations, as could be expected for electrostatic interactions. On the contrary, pepsin-extracted cartilage collagen forms aggregates of covalent nature, the number of which is independent of concentration. Viscosity measurements show two different interaction mechanisms: a short distance one which can be identified with the electric birefringence-detected aggregation, and a long distance superstructure which disappears when salt is added to the solution.
mesh_terms: D000085:Acetates; D000818:Animals; D001718:Birefringence; D002358:Cartilage, Articular / Q000378:metabolism; D002417:Cattle; D003094:Collagen; D004563:Electrochemistry; D066298:In Vitro Techniques; D010434:Pepsin A; D011402:Pronase / Q000494:pharmacology; D011489:Protein Denaturation; D012867:Skin / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D012995:Solubility; D014783:Viscosity
chemical_list: D000085:Acetates; D012965:Sodium Chloride; D003094:Collagen; D010434:Pepsin A; D011402:Pronase