Determination of Protein Triple Helix Structure by Circular Dich

Circular Dichroism (CD) is a technique commonly used to study protein structure, particularly suitable for measuring the relative content of α-helix, β-sheet, β-turn, and random coil structures in proteins. The triple-helix structure of proteins, especially the triple-helix structure of collagen, can also be analyzed by circular dichroism. In the triple-helix structure of collagen, each helix is composed of three polypeptide chains. These three polypeptide chains are intertwined with each other, interacting through hydrogen bonds and other non-covalent bonds to form a stable structure. The triple-helix structure has specific spectral characteristics in circular dichroism:

 

1. Wavelength Characteristics

The triple-helix structure usually manifests as absorption peaks in the near-ultraviolet region (about 190 to 240 nanometers). In particular, the triple-helix structure of collagen will show a significant negative absorption peak at about 220 nanometers.

 

2. Structure Sensitivity

The circular dichroism signal is very sensitive to changes in protein structure and can be used to monitor the effects of environmental factors such as temperature, pH, and solvents on the triple-helix structure of proteins.

 

By analyzing circular dichroism spectra, the presence and stability of the triple-helix structure in proteins can be qualitatively and quantitatively evaluated. This is of great significance for studying the structure and function of collagen and other proteins containing a triple-helix structure.