Identifying deer-hide gelatin of Tarim red deer (Cervus elaphus yarkandensis) through active peptide analysis

Deer hide gelatin (DHG) is a food and pharmaceutical product derived from deer hide. However, the identifying the subspecies origin of red deer in the DHG still poses challenges. This study describes a novel approach for identifying DHG derived from Tarim red deer. It employs labeled peptides specific to species-specific proteins found in Tarim red deer. Species-specific proteins of Tarim red deer were identified and validated using proteomic techniques. A peptide derived from a specific protein of Tarim red deer was synthesized and employed for the development of the liquid chromatography multiplex reaction monitoring mass spectroscopy method. The capability of this method was evaluated using homemade gelatin for testing purposes. Proteomic analysis revealed the presence of a diverse range of proteins in the skin of the Tarim red deer, including Ig-like and serpin domain-containing proteins. The peptide derived from the species-specific Ig-like domain-containing protein of Tarim red deer demonstrated exceptional specificity towards DHG. Standard Pep-1 solutions were examined at a concentration of 1 × 10⁻⁴ mg/mL using liquid chromatography multiplex reaction monitoring mass spectrometry. DHG from Tarim red deer could be accurately detected using this technology. The effectiveness of the synthetic Tarim red deer-specific peptide in enhancing motor function and neuromuscular coordination was confirmed through assessment of glutathione content and superoxide dismutase activity, as well as Drosophila climbing assay and "Smurf test". The method developed in this study could improve the quality control of DHG from Tarim red deer and the development of health products and could also be applied to the identification of other foods and drugs containing protein components.