Thermal Denaturation of Collagen Analyzed by Isoconversional Method

Abstract

An isoconversional method is proposed to be used for evaluating activation energy of protein denaturation. Applied to DSC data on collagen denaturation, the method yields an activation energy that decreases throughout the process. The Lumry-Eyring model gives an explanation for this decrease and affords estimates for the enthalpy of the reversible step and the activation energy of the irreversible step of denaturation. The reversible unfolding is detectable by multi-frequency temperature-modulated DSC.

Thermal denaturation and structural changes of α-helical proteins in keratins

“…The specific simplicity of the approach is at this stage given preference over more complex iso-conversional methods, as, e.g., discussed for collagen by Vyazovkin et al (2007). This is due to the obvious inhomogeneity of helix denaturation in hair, as reflected by the shoulder towards higher temperatures in Fig.…”

Estimation of the overall kinetic parameters of enzyme inactivation using an isoconversional method

“…Such "model free" methods have been extensively used for numerous kinetic analysis of reactions involving solids, where the reaction rate is also given by a product between a temperature and a conversion factor [14,15,16,17,18,19,20]. The proposed procedure belongs to a group of kinetic methods, like "constant velocity plot" [21] and "competition plot" [22] where the judicious restrictions imposed to kinetic measurements result in a safer analysis of experimental data.…”

Physical Processes

“…Therefore, the actual value of ΔH 0 can be larger than 210 kJ mol . The inceptive application [185] of an isoconversional method to denaturation of collagen has been followed by a series of isoconversional studies on several proteins. Several studies [193][194][195][196] have been conducted on thermal denaturation of collagen, including denaturation of dry [195] and fish [196] collagen as well as vitrified collagen gels [194].…”

“…As an example of isoconversional treatment of the helix-coil transition, we consider the thermal denaturation of collagen [185]. The latter is a fibrous protein present in animal connective tissue.…”