Study On Polysaccharides Composition And Differential Protein Expression Of Lycium Barbarum "Ningqi-1" In Different Origins

In this paper,Lycium Barbarum "Ningqi-1" from five origins including Xinjiang Jinghe,Gansu Guazhou,Qinghai Delingha,Ningxia Zhongning and Inner Mongolia Wulateqianqi were taken as the research objects.Water extraction was used to obtain Lycium Barbarum polysaccharides(LBP)from the fruits of Lycium Barbarum in different origins.The content of polysaccharide,molecular weight,monosaccharide composition and structural characteristics of LBP were determined.Based on the technique of isotope labeling relative and absolute quantification(iTRAQ)combined with two-dimensional liquid chromatography tandem mass spectrometry(2D LC-MS/MS),protein fingerprints were acquired.And differential proteins were screened by(Gene Ontology)GO enrichment analysis.To establish the basis for further determining the protein expression differences in the biosynthetic pathway of LBP from five origins.The main results were as follows:1.The LBP contents of the fruits of Lycium Barbarum in five origins Xinjiang Jinghe,Gansu Guazhou,Qinghai Delingha,Ningxia Zhongning and Inner Mongolia Wulateqianqi were 0.73%,0.97%,1.23%,1.23%and 1.14%respectively.The extraction rates of LBP were 0.30%,0.36%,0.26%,0.30%and 0.31%respectively.The contents of polysaccharide and protein in LBP from Qinghai Delingha were both the highest,which were 76.24%and 6.70%respectively.The content of aluronic acid in LBP from Ningxia Zhongning was the highest(25.95%).And the content of polysaccharide(59.02%),protein(5.44%)and uronic acid(22.36%)in LBP from Inner Mongolia Wulateqianqi were all the lowest.The molecular weight of LBP from Ningxia Zhongning and Inner Mongolia Wulateqianqi were relatively large,and that from Gansu Guazhou was the smallest.2.Ultraviolet and infrared spectroscopy of LBP from different origins showed that there were obvious binding proteins and infrared spectral peaks of-NH2 or-NH-groups,methyl(-CH3)and methylene(-CH2-)groups,indicating a typical molecular skeleton of polysaccharides,It could be drawn a conclusion that LBP from five origins were alll proteoglycan mainly containing ?-D-pyranose residue.In the five origins,"Ningqi-1" LBP contained 6 kinds of monosaccharides including arabinose,glucose,galactose,rhamnose,xylose and mannose.The ratios of arabinose,glucose and galactose in LBPmolecule were very high,and there were some differences in monosaccharide composition of LBP in different origins.The molar ratio of glucose in LBP from Ningxia Zhongning was slightly higher than that of arabinose.However,for LBP from Xinjiang Jinghe,Inner Mongolia Wulateqianqi,Gansu Guazhou and Qinghai Delingha,the molar ratio of arabinose was the highest followed by glucose or galactose.3.The total protein number of 4852 in LBP from five origins were identified by iTRAQ.The number of differential proteins screened from the group of Qinghai Delingha/Ningxia Zhongning was the most(1015),and the number of differential proteins screened from the group of Inner Mongolia Wulateqianqi/Ningxia Zhongning was the least(166).The results of GO enrichment analysis showed that there were significant differences in protein expression among Lycium Barbarum "Ningqi-1" from five origins,which involved in biological processes,molecular functions,and cellular components.For biological processes,differentially expressed proteins were mainly associated with metabolic processes,cellular processes and single biological processes.For molecular functions,differentially expressed proteins were mainly associated with molecular binding and catalytic activity.For cellular components,differentially expressed proteins were mainly associated with cells,organelles and membranes.Comparing the Lycium Barbarum in Gansu Guazhou and Ningxia Zhongning,the difference in protein expression was most significant in cell components.Comparing the Lycium Barbarum in Qinghai Delingha and Gansu Guazhou,the difference in protein expression was most significant in biological process.Comparing the Lycium Barbarum in Gansu Guazhou and Xinjiang Jinghe,protein expression levels in biological process and cell components were significantly different.