Abstract: In order to provide an experimental basis for preparing collagen from the skin of Thamnaconus modestus, the conditions for enzymatic extraction of collagen from T. modestus skin with pepsin were optimized in this study, and we also analyzed the structure of the obtained collagen. A buffer pH of 3.0 for pretreatment, an enzyme dosage of 16 800 U/g, a solid-to-solvent ratio of 1:30 (g/mL) and a hydrolysis time of 21.5 h were found to be the optimum conditions to obtain a higher extraction yield of 27.6%. Amino acid analysis, UV spectroscopy, Fourier transform infrared spectroscopy, and sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (SDS-PAGE) demonstrated that the collagen from T. modestus might be classified as type I collagen containing a unique triple helical structure.

Key words: Thamnaconus modestus, collagen, extraction, structural characterization