Comparative Proteomics Of Donkey And Bovine Whey And Milk Fat Globule Membrane During Lactation

Donkeys have a variety of economic approaches for meat,skin,medicine,milk,and service.Service use is the main animal use route of donkeys.In recent years,with the continuous improvement of agricultural mechanization and the gradual improvement of transportation conditions,the use value of donkey as a service is rapidly decreasing and the breeding donkey industry has gradually developed towards the side industry in China.Donkey milk is the main by-product of the donkey breeding industry,has high nutritional value,and is a precious dairy resource.Compared to bovine milk,the nutritional composition of donkey milk is closer to that of human milk and is considered a potential substitute for breast milk.Comprehensive analysis of protein composition is the basis of protein function research,but there are few in-depth reports on the dynamic changes of donkey and bovine milk proteome during lactation.Considering that the casein has been studied thoroughly,this study conducted quantitative proteomics studies on donkey colostrum and mature milk protein from the whey and milk fat globule membrane.The functional protein of donkey milk,and compare the different proteins from donkey and bovine milk during lactation,enrich the information about protein composition and gene function of donkey and bovine milk,and provide insights into the functions of donkey and bovine milk in different lactation stages.This new idea provides a scientific basis for the production of infant formula milk closer to breast milk.The main research results are as follows:The label-free quantitative proteomics method was used to characterize the whey proteome,and the parallel reaction monitoring(PRM)method was used to verify the accuracy of the LC-MS / MS results.A total of 300 kinds of whey proteins were identified in donkey colostrum and mature milk,and a total of 275 kinds of whey proteins.288 and 287 whey proteins were identified in donkey colostrum and mature milk,of which 18 were differentially expressed;13 and 12 specific expressions of whey protein were identified in donkey colostrum and mature milk,respectively.GO functional annotation analysis shows that the differentially and specifically expressed proteins are mainly involved in cellular processes,stimuli,metabolic processes,and biological regulation;the main molecular functions involved include binding function,catalytic activity,and molecular function regulation;the main involved molecular components It is the cell,the cell part and the extracellular area.KEGG pathway analysis shows that most differentially and specifically expressed proteins are related to malaria,systemic lupus erythematosus,or antigen processing and presentation.The PRM experiment verified the accuracy of the LC-MS / MS results.Donkey milk is rich in high-level proteins such as lysozyme and polymerized immunoglobulin receptors.It has bacteriostatic,tumor proliferation and immune promotion effects.The high abundance of apolipoprotein B in donkey colostrum plays an important role in regulating lipid metabolism and promoting cholesterol homeostasis;the high abundance of cathepsin B and TGF-? in donkey mature milk in the body immune response,inhibiting tumor proliferation and regeneration play a more important role in enteritis in children.The label-free quantitative proteomics method was used to characterize the MFGM proteome,and the parallel reaction monitoring(PRM)method was used to verify the accuracy of the LC-MS / MS results.A total of 947 to MFGM proteins were identified in donkey colostrum and mature milk,of which there were 868 MFGM proteins.Donkey colostrum and mature milk contain 902 and 913 MFGM proteins,respectively.A total of 61 differentially expressed MFGM proteins were identified.34 and 45 specific expression of MFGM proteins were identified in donkey and donkey mature milk.GO functional annotation analysis shows that the biological process subpopulations with the most participation of MFGM protein mainly include cellular process,metabolic process,biological regulation and biological process regulation;common molecular functions are binding and catalytic activity;MFGM protein mainly comes from cells and cell parts.The main KEGG pathways involved in the donkey milk MFGM protein at different lactation stages include endocytosis,fever,Alzheimer's disease,cancer pathway and human papillomavirus infection.In the PRM verification experiment,the up-regulated apolipoprotein A1(F6Z2L5)in colostrum MFGM was enriched in colostrum,while the up-regulated lipid droplet coating protein(F6Q9R1)in mature milk was highly enriched in donkey normal milk.The PRM experiment verified the accuracy of the LC-MS / MS results.40 S ribosomal protein S25(RPS25),60 S ribosomal protein L11(RPL11)and apolipoprotein A1 play a role in the anti-cancer process and the rapid growth and development of neonatal tissues in donkey colostrum MFGM;the nerves such as protoplasm and lipid-coated eggs may play a more important role in the learning and memory of newborns in donkey mature milk MFGM proteins.Using qualitative proteomics technology,a total of 765 whey proteins were identified in donkey and bovine milk whey proteins in different lactation stages,and 387,383,447 and 529 kinds of whey proteins were identified in donkey colostrum,donkey mature milk,bovine colostrum and bovine mature milk,respectively.GO functional annotation analysis shows that the biological processes that donkey and bovine milk whey proteins participate in different lactation stages mainly include stimuli,metabolic processes,positioning,developmental processes and immune system processes;the molecular functions involved include hydrolase activity and regulation enzyme Activity;common cellular components include extracellular regions.KEGG pathway analysis showed that donkey colostrum,donkey mature milk,bovine colostrum and bovine mature milk whey protein correspond to 23,24,26 and 25 pathways in the KEGG database;the processing of cytoplasmic reticulum protein is a way for the four groups of samples to participate together.Donkey colostrum and bovine colostrum specifically expressed 181 and 241 whey proteins respectively;donkey mature and bovine mature milk specifically expressed 183 and 329 whey proteins.Donkey colostrum and donkey mature milk specifically expressed whey protein at 50 and 46 species respectively;bovine colostrum and bovine mature milk specifically expressed whey protein at 66 and 148 species,respectively.The difference of whey protein between donkey and cow milk is much larger than its composition of whey protein in different lactation periods.Donkey milk whey protein may play an important role in signaling pathways that inhibit tumorigenesis;bovine milk plays a more important role in host defense and inflammation.Using qualitative proteomics technology,a total of 2269 MFGM proteins were identified in donkey and bovine milk MFGM at different lactation stages,and 1236,1243,1393 and 1753 proteins were identified in donkey colostrum,donkey mature milk,bovine colostrum,and bovine mature milk whey,respectively.The biological processes in which the donkey and bovine milk MFGM proteins in different lactation stages participate mainly include single biological processes,metabolic processes,localization,bioadhesion and immune system processes;the molecular functions involved include binding functions,catalytic activities and structural molecular activities;the common cellular components include organelles,extracellular regions and other components.Donkey colostrum,donkey mature milk,bovine colostrum,and bovine mature milk MFGM proteins correspond to 62,41,51 and 59 pathways in the KEGG database,respectively.The MFGM proteins in the four groups of samples participate in metabolic pathways,protein processes and ribosome Equal signal path.Donkey colostrum and bovine colostrum specifically expressed 422 and 579 MFGM proteins respectively;donkey mature and bovine mature milk specifically expressed 385 and 895 MFGM proteins.Donkey colostrum and donkey mature milk specifically expressed 154 and 161 MFGM proteins;bovine colostrum and bovine mature milk specifically expressed 159 and 519 MFGM proteins,respectively.Donkey milk MFGM protein plays a more important role in inhibiting tumors,blood and other related diseases,and bovine milk MFGM plays a more important role in fighting inflammation,fighting bacteria and viruses and other biological processes.This study provides a new idea for further understanding the function of donkey milk and bovine milk protein,and provides a scientific basis for the production of functional infant formula milk powder close to breast milk.