The Effect of Pressure on Thermal Stability and In Vitro Fibril Formation of Collagen

Abstract

The effects of pressure on thermal denaturation and in vitro fibril formation of acid soluble collagen from calf skin were studied with various solvent conditions under high pressure of up to 4,000 atm. For all the solvent systems, the thermal denaturation was depressed by pressure, e.g., the apparent denaturation temperature at pH 4.0 increased from 37.5°C at 1 atm to 44.5°C at 1,400 atm. The pressure-enhanced thermal stability of collagen indicates that the volume change due to the helix-to-coil transition of this protein is positive in water. The fibril formation in both the nucleation and growth phases was extensively retarded by pressure in a relatively low region of up to 500 atm, indicating the positive activation volume of this fibril formation process. These results seemed to support a hypothesis that the protein-water interaction plays a dominant role in the structural stability of the triple helix and fibrils of collagen. © 1983, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.