Insights into the Structural and Thermal Properties of Pepsin-Soluble Collagen from Daggertooth pike conger (Muraenesox cinereus)

Pepsin soluble collagen (PSC) is a type-1 collagen which is abundant in skin. The pepsin soluble collagen was successfully extracted from the skin of Daggertooth pike conger (Muraenesox cinereus) by using the conventional method of salt precipitation followed by dialysis. Pepsin-soluble collagen showed a yield of 10.12% on wet matter basis and 25.5% on dry matter basis. The triple helical structure of collagen was confirmed by Fourier Transform Infrared Spectroscopy (FTIR) and UV-Visible spectrophotometry. Isolated PSC was confirmed as type 1 collagen by Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). FTIR spectra of PSC suggested that the secondary structure of the triple helical collagen was intact even after pepsin digestion. Pepsin-soluble collagen was soluble in acidic pH with maximum solubility at pH 4. The solubility was found to be decreased with an increase in the concentration of sodium chloride with a minimum solubility at 4%. The present PSC isolate from eel fish exhibited comparatively high thermal stability of 36 ͦ C. Morphological analysis by Scanning electron microscopy (SEM) revealed a porous structure and comparatively high thermal stability makes it a promising biomaterial.