Analysis of peptides and proteins from Asini Corii Colla using nano LC-Q-Exactive-MS/MS / 中国中药杂志

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.

Analysis of proteins secreted by bone marrow stromal cells using shotgun mass spectrometry / 解剖学报

Objective Using shotgun mass spectrometry to detect proteins probably contained in bone marrow stromal cells(BMSCs) conditioned medium. MethodsMixed with BMSCs conditioned medium was divided into two parts which is(>5kD and <5kD) by means of ultrafiltration. The two parts were used to culture neural stem cells(NSCs) separately, and the proportions of neurons, astrocytes and oligodendrocytes in the offsprings of NSCs were calculated, then the effective part that could regulate the differentiation of NSCs was detected by Shotgun mass spectrometry. Results The BMSCs conditioned medium which is >5kD could promote the NSCs differentiate into more neurons and oligodendrocytes. The SDS-PAGE of this part showed that the most proteins were above 14kD, then the protein bands were enzymed. In total, 456 proteins were identified by Shotgun mass spectrometry after all the protein bands were enzymed, there were 154 similar proteins, 17 hypothetical proteins and 56 unknown proteins. And in the rest of 229 proteins, most of them were cytoskeletal proteins, secreted proteins, signal transduction proteins, enzymes, transporter and so on. Conclusion Many proteins secreted by BMSCs could regulate the differentiation of NSCs so as to prove the protein components probably existed in the BMSCs conditioned medium.