This study explored how N-glycosylation influences the resistance of human lactoferrin(HLF)and bovine lac-toferrin(BLF)to digestion during simulated infant gastrointestinal conditions.Native and deglycosylated lac-tof...This study explored how N-glycosylation influences the resistance of human lactoferrin(HLF)and bovine lac-toferrin(BLF)to digestion during simulated infant gastrointestinal conditions.Native and deglycosylated lac-toferrins were subjected to in vitro simulated infant gastrointestinal digestion,followed by structural and biochemical analyses.The results showed that natural HLF retained approximately 24.5%intact protein at I10 min,whereas BLF was almost completely degraded(<5%).The degree of hydrolysis at I10 min was significantly lower for HLF(19.1%)than BLF(34.2%)(P<0.05).Deglycosylation accelerated proteolysis by 1.23-fold at I10 min for HLF and 1.20-fold at I5 min for BLF(P<0.05),without altering secondary structure,but associated with premature tertiary unfolding(fluorescence red-shift~6 nm)and increased surface electronegativity at I5 min(ζ-potential:21.1 vs16.8 mV,P<0.05).Molecular docking suggested glycan shielding may reduce enzyme binding by 0.3-2.1 kcal/mol.Glycoproteomic analysis identified the intact glycopeptide harboring Asn138-glycan adjacent to a trypsin cleavage site.These results indicated that N-glycans may confer resistance by ste-rically shielding proteolytic cleavage sites and modulating surface charge.The complex sialylated glycans of HLF were associated with greater resistance compared to the simpler oligomannose structures of BLF.These findings suggest N-glycosylation as an important structural contributor of lactoferrin digestibility and offer insights for designing glycoengineered lactoferrin for infant nutrition.展开更多
The potential for Monascus pigments(MPs)production in a mixture of Chinese rice wine lees,soaked rice wastewater and broken rice was explored.MPs production reached 120.1 U/mL with optimal solid-liquid ratio of cultur...The potential for Monascus pigments(MPs)production in a mixture of Chinese rice wine lees,soaked rice wastewater and broken rice was explored.MPs production reached 120.1 U/mL with optimal solid-liquid ratio of culture medium 1:10 and 20 g/L broken rice addition at shake flask level.We further explored the effects of stirring speed on MPs production in 7.5 L agitated bioreactor.The stirring speed had a great impact on cell morphology and the maximum MPs concentration and yield were 128.4 U/mL and 8174 U/g respectively at 400 rpm.The soluble chemical oxygen demand for the soaked rice wastewater decreased by 78.7%,which was mainly due to the intake of carbohydrates,organic acids and amino acids.Furthermore,a simultaneous fermentation process and production system with two-stage stirring speed control strategy was further developed in the 50 L pilot scale,in which the MPs production reached 158.9 U/mL.Meanwhile,Chinese rice wine wastes were fully utilized without addition of organic solvents during the process and no generation of new waste.Our results showed that Monascus was capable of converting Chinese rice wine wastes into natural pigments by submerged fermentation,which could provide an economic and environmentally friendly approach to reduce the cost of wastes treatment as well as high-value utilization.展开更多
基金support of National Natural Science Foundation of China(32372246)the National Foreign Expert Project of China(H20250240)Fundamental Research Funds for the Central Universities(JUSRP202416004).
文摘This study explored how N-glycosylation influences the resistance of human lactoferrin(HLF)and bovine lac-toferrin(BLF)to digestion during simulated infant gastrointestinal conditions.Native and deglycosylated lac-toferrins were subjected to in vitro simulated infant gastrointestinal digestion,followed by structural and biochemical analyses.The results showed that natural HLF retained approximately 24.5%intact protein at I10 min,whereas BLF was almost completely degraded(<5%).The degree of hydrolysis at I10 min was significantly lower for HLF(19.1%)than BLF(34.2%)(P<0.05).Deglycosylation accelerated proteolysis by 1.23-fold at I10 min for HLF and 1.20-fold at I5 min for BLF(P<0.05),without altering secondary structure,but associated with premature tertiary unfolding(fluorescence red-shift~6 nm)and increased surface electronegativity at I5 min(ζ-potential:21.1 vs16.8 mV,P<0.05).Molecular docking suggested glycan shielding may reduce enzyme binding by 0.3-2.1 kcal/mol.Glycoproteomic analysis identified the intact glycopeptide harboring Asn138-glycan adjacent to a trypsin cleavage site.These results indicated that N-glycans may confer resistance by ste-rically shielding proteolytic cleavage sites and modulating surface charge.The complex sialylated glycans of HLF were associated with greater resistance compared to the simpler oligomannose structures of BLF.These findings suggest N-glycosylation as an important structural contributor of lactoferrin digestibility and offer insights for designing glycoengineered lactoferrin for infant nutrition.
基金This work was supported by the National Key Research and Development Program of China(2021YFC2104001,2022YFC2105501)the China Postdoctoral Science Foundation(2022M711368)+1 种基金the Fundamental Research Funds for the Central Universities(JUSRP122037)the Natural Science Foundation of Jiangsu Province,Science,and Technology Department of Jiangsu Province,China(BK20221081).
文摘The potential for Monascus pigments(MPs)production in a mixture of Chinese rice wine lees,soaked rice wastewater and broken rice was explored.MPs production reached 120.1 U/mL with optimal solid-liquid ratio of culture medium 1:10 and 20 g/L broken rice addition at shake flask level.We further explored the effects of stirring speed on MPs production in 7.5 L agitated bioreactor.The stirring speed had a great impact on cell morphology and the maximum MPs concentration and yield were 128.4 U/mL and 8174 U/g respectively at 400 rpm.The soluble chemical oxygen demand for the soaked rice wastewater decreased by 78.7%,which was mainly due to the intake of carbohydrates,organic acids and amino acids.Furthermore,a simultaneous fermentation process and production system with two-stage stirring speed control strategy was further developed in the 50 L pilot scale,in which the MPs production reached 158.9 U/mL.Meanwhile,Chinese rice wine wastes were fully utilized without addition of organic solvents during the process and no generation of new waste.Our results showed that Monascus was capable of converting Chinese rice wine wastes into natural pigments by submerged fermentation,which could provide an economic and environmentally friendly approach to reduce the cost of wastes treatment as well as high-value utilization.
