Temperature induced denaturation of collagen in acidic solution

Area of Science:

• Biochemistry
• Materials Science
• Biophysics

Background:

• Collagen, a vital structural protein, undergoes denaturation affecting its properties.
• Understanding collagen denaturation is crucial for biomaterial development and biological studies.

Purpose of the Study:

• To investigate the denaturation process of collagen in acetic acid.
• To differentiate between collagen defibrillation and denaturation using multiple analytical techniques.

Main Methods:

• Ultra-sensitive differential scanning calorimetry (US-DSC) to detect thermal transitions.
• Circular dichroism (CD) to monitor changes in triple helix content.
• Laser light scattering (LLS) to analyze changes in molecular size and shape.

Main Results:

• US-DSC revealed a bimodal transition, with a reversible shoulder transition below 35°C and irreversible transitions above 37°C.
• CD indicated a gradual decrease in triple helix content below 35°C, followed by a sharp decrease at higher temperatures.
• LLS showed a decrease in hydrodynamic radius and an increase in R(g)/R(h) ratio, suggesting defibrillation preceding denaturation.

Conclusions:

• The shoulder transition corresponds to collagen defibrillation, while the major transition represents denaturation.
• Collagen defibrillation occurs before denaturation and becomes irreversible above 37°C.
• The combined methods provide a comprehensive understanding of collagen's thermal behavior and structural changes.