[Analysis of peptides and proteins from Asini Corii Colla using nano LC-Q-Exactive-MS/MS]

This paper aims to systematically analyze the peptides and proteins from Asini Corii Colla(ACC) through shotgun proteomics. After high-pH reversed-phase fractionation, the proteins and peptides in the hydrolysate of ACC were further separated by nano LC-Q-Exactive-MS/MS under the following conditions: Thermo Scientific EASY column(100 μm×2 cm, 5 μm, C_(18)) as precolumn, Thermo Scientific EASY column(75 μm×100 mm, 3 μm, C_(18)) for solid phase extraction, gradient elution with 0.1% formic acid in water(mobile phase A) and 84% acetonitrile in water containing 0.1% formic acid(mobile phase B), and MS in positive ion mode. Based on Uniprot_Equus caballus, MS data, and literature, 2 291 peptides were identified from ACC by MaxQuant, with 255 Maillard reactions(AML, CML, CEL)-modified peptides identified for the first time. Through alignment, the peptides were found to belong to 678 equine proteins. In conclusion, the combination of nano LC-Q-Exactive-MS/MS and shotgun proteomics achieved rapid and accurate identification of the proteins and peptides in ACC, which provides the key information and new insights for further investigation of chemicals and effective substances in ACC.