基于Label-free定量多肽组学的鹿角胶与鹿皮胶糖基化肽研究

Label-free quantitative peptidomics-based analysis on glycopeptides in deerhorn gelatin and deer-hide gelatin

该文采用纳升液相-串联质谱法对鹿角胶(DCG)与鹿皮胶(DHG)样品的糖基化肽类进行分析,以Label-free定量(LFQ)多肽组学方法对糖基化肽类成分的相对含量进行比较分析,筛选确定DCG与DHG样品中差异显著的糖基化肽类成分。结果从5批次DCG样品中共鉴定了5736个肽段,其中含半乳糖基化赖氨酸(galactosyl-hydroxylysine,GalHyl)的肽段共213个,含葡萄糖半乳糖基化赖氨酸(glucosyl-galactosyl-hydroxylysine,Glc-Gal-Hyl)的肽段共102个;从5批次DHG样品中共鉴定了6836个肽段信息,含Gal-Hyl的肽段共250个,含Glc-Gal-Hyl的肽段共98个。以肽段峰面积差异大于3倍,且组间有极显著性差异(P<0.01)为条件筛选差异肽段,确定444个肽段在DCG与DHG中差异显著,其中含Gal-Hyl的肽段共16个,含Glc-Gal-Hyl的肽段共5个;进一步以选择离子峰的峰型、峰面积标准偏差及差异倍数筛选确定了5个在DCG与DHG样品中差异极显著的糖基化肽,可作为潜在的区分DCG与DHG的标记物。该文研究为DCG与DHG的鉴别区分提供了新的思路,为胶类中药的物质基础研究、质量标准提升研究提供方法依据,具有较好的理论意义与应用价值。

Nano-LC-MS/MS was used to analyze trypsin digested deer-horn gelatin(DCG)and deer-hide gelatin(DHG)samples.The glycopeptides in DCG and DHG were quantified by Label-free quantitative(LFQ)peptidomics,on the basis of which the glycopeptides with significant difference in DCG and DHG were determined.As a result,5736 peptides were identified from DCG samples,including 213 galactosyl-hydroxylysine containing peptides(Gal-Hyl-peptides)and 102 glucosyl-galactosyl-hydroxylysine containing peptides(Glc-Gal-Hyl-peptides),while 6836 peptides were identified from DHG samples,among which there were 250 Gal-Hyl-peptides and 98 Glc-Gal-Hyl-peptides.With over 3-fold peak area difference and highly significant intergroup difference(P<0.01)as the screening criteria,444 differential peptides were determined in DCG and DHG,including 16 Gal-Hyl-peptides and 5 Glc-Gal-Hyl-peptides.Then XIC peak shapes,standard deviation of peak area,and fold change were applied for further screening and 5 glycopeptides with significant differences in DCG and DHG were confirmed,which could serve as potential biomarkers for distinguishing DCG and DHG.The present study provided ideas and strategies for the in-depth investigation on the discrimination of DCG and DHG and is of good theoretical significance and application value for the further research on chemical constituents and quality control of gelatin derived Chinese medicinals.