Thermal properties of collagen in helical and random coiled states in the temperature range from 4° to 300°K

✍ Scribed by E. L. Andronikashvili; G. M. Mrevlishvili; G. Sh. Japaridze; V. M. Sokhadze; K. A. Kvavadze

• Publisher: Wiley (John Wiley & Sons)
• Year: 1976
• Tongue: English
• Weight: 707 KB
• Volume: 15
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1976.360151010

✦ Synopsis

Abstract

The low‐temperature heat capacity of collagen (in the hydrated and dehydrated states) and the large entropy of collagen in the coiled state relative to the same protein in the helical state were investigated. The heat capacity for collagen in the solid state in the temperature range 4°–50° K changes proportionally to the square of temperature (C~p~ ∼ T^2^). Above 50°K there is a linear dependence (C~p~ ∼ T). The differences in the character of temperature dependence of heat capacity for the hydrated and dehydrated collagen show the importance of the specific interaction of water molecules with polypeptide chains of this protein. The peculiarities of the temperature dependence of the heat capacity difference (Δ__C__~p~) of hydrated denatured (random coiled) and hydrated native (helical) collagen are observed at 15°, 120°, and 240°K. These differences are caused by the varying degree of ordering of the hydrate water molecules in native and denatured collagen macromolecules. At all temperatures (4°–300°K) the entropy of the random coiled state is higher than that of collagen in the native state and at 298°K Δ__S__ = ∫ (Δ__C__~p~/T)dT = 0.8 cal/100 g °K.