Characterization and comparison site-specific N-glycosylation profiling of milk fat globule membrane proteome in donkey and human colostrum and mature milk.

Milk fat globule membrane (MFGM) proteins are highly glycosylated and involved in various biological processes within the body. However, information on site-specific N-glycosylation of MFGM glycoproteins in donkey and human milk remains limited. This study aimed to map the most comprehensive site-specific N-glycosylation fingerprinting of donkey and human MFGM glycoproteins using a site-specific glycoproteomics strategy. We identified 1,360, 457, 2,617, and 986 site-specific N-glycans from 296, 77, 214, and 196 N-glycoproteins in donkey colostrum (DC), donkey mature milk (DM), human colostrum (HC), and human mature milk (HM), respectively. Bioinformatics was used to describe the structure-activity relationships of DC, DM, HC, and HM MFGM N-glycoproteins. The results revealed differences in the molecular composition of donkey and human MFGM N-glycoproteins and the dynamic changes to site-specific N-glycosylation of donkey and human MFGM glycoproteins during lactation, deepening our understanding of the composition of donkey and human MFGM N-glycoproteins and their potential physiological roles.

Structural characterization, α-glucosidase inhibitory activity and antioxidant activity of neutral polysaccharide from apricot (Armeniaca Sibirica L. Lam) kernels.

Screening for α-glucosidase inhibitors and antioxidants from natural sources that could reduce postprandial glucose in diabetic patients and reduce oxidative stress had attracted considerable interest. In this study, a neutral polysaccharide (AP-1) with a triple helix structure was isolated and purified from the residue of apricot (Armeniaca sibirica L. Lam.) kernels by using DEAE-52 and Sephadex G-100 columns. The molecular weight of AP-1 was 23.408 kDa and consisted mainly of glucose with trace amounts of arabinose, galactose, and mannose, which had molar percentages of 98.48, 0.63, 0.62 and 0.27 %, respectively. The main chain of AP-1 was composed of →4)-α-D-Glcp-(1 â†’ interlinked, and α-D-Glcp-(1 â†’ was attached as a branched chain at the O-6 position of →4,6)-α-D-Glcp-(1→. In addition, AP-1 exhibited stronger α-glucosidase inhibition and free radical scavenging ability compared to crude polysaccharides. Therefore, AP-1 could be used as a potential natural hypoglycemic agent and antioxidant in the treatment of diabetes mellitus.

Quantitative label-free site-specific glycoproteomic analysis of the milk fat globule membrane protein in human colostrum and mature milk.

Human milk fat globule membrane (MFGM) proteins, which are N-glycosylated, play essential roles in neonatal development and physiological health. However, the profiles and landscape changes in the site-specific N-glycosylation of human MFGM proteins during lactation remain unclear. Therefore, in this study, based on an intact glycopeptide-centred strategy, 2617 unique site-specific N-glycans of 221 MFGM glycoproteins in human colostrum and 986 unique site-specific N-glycans of 200 MFGM glycoproteins in mature milk were characterised and quantified using label-free glycoproteomics. With milk maturation, 33 site-specific N-glycans on 10 N-glycoproteins increased significantly, and 113 site-specific N-glycans on 25 N-glycoproteins decreased significantly. Moreover, human MFGM glycoproteins with core-α1,6-fucosylated structures and Lewis and sialylated branching structures play a role in the biological processes of antigen processing and presentation. This study reveals the dynamic changes in human MFGM protein N-glycosylation patterns during lactation. Meanwhile, the study deepens our understanding of site-specific N-glycosylation of human MFGM glycoproteins. The results of the study provide a background reference for the development of infant formulas.

Highly efficient charge transfer from small-sized cadmium sulfide nanosheets to large-scale nitrogen-doped carbon for visible-light dominated hydrogen evolution.

Slow charge transfer and carrier recombination are key issues in photocatalytic reactions. The current solution is to load small-sized cocatalysts onto large-sized photocatalysts. Here a new strategy is proposed. Small-sized photocatalysts of cadmium sulfide (CdS) nanosheets are grown onto large-sized cocatalysts of N-doped amorphous carbon (a-CN) to construct CdS @ a-CN photocatalysts. Photoluminescence spectra and transient photocurrent demonstrate that optimized CdS @ a-CN shows effective charge separation compared with CdS. The corresponding photocatalytic H2 yield of optimized CdS @ a-CN is âˆ¼244 µmol, which is 3.6 times higher than that of CdS. Besides, the hydrogen yield for CdS under visible-light irradiation is significantly improved from âˆ¼44 µmol to âˆ¼217 µmol for the optimized CdS @ a-CN. Our design strategy provides an effective way to construct photocatalytic systems with outstanding photocatalytic performance.

Microbial Diversity and Non-volatile Metabolites Profile of Low-Temperature Sausage Stored at Room Temperature.

Sausage is a highly perishable food with unique spoilage characteristics primarily because of its specific means of production. The quality of sausage during storage is determined by its microbial and metabolite changes. This study developed a preservative-free low-temperature sausage model and coated it with natural casing. We characterized the microbiota and non-volatile metabolites in the sausage after storage at 20°C for up to 12 days. Bacillus velezensis was the most prevalent species observed after 4 days. Lipids and lipid-like molecules, organoheterocyclic compounds, and organic acids and their derivatives were the primary non-volatile metabolites. The key non-volatile compounds were mainly involved in protein catabolism and ß-lipid oxidation. These findings provide useful information for the optimization of sausage storage conditions.

Spectroscopic and docking studies of the interaction mechanisms of xylitol with α-casein and κ-casein.

The molecular interactions of xylitol (XY) with α-casein (α-CN) and κ-casein (κ-CN) at pH 7.4 as a function of temperature (298, 308, and 318 K) were characterized by multispectral techniques and molecular docking. The fluorescence results showed that XY strongly quenched the intrinsic fluorescence of α- and κ-CN by static quenching, as well as the presence of a single binding site for XY on both proteins with a binding constant value of ∼105 L/mol. The binding affinity of both proteins for XY decreased with increasing temperature, and Van der Waals forces, hydrogen bonding and protonation were the key forces in the interactions. The addition of XY altered the polarity of the microenvironment of proteins and changed their secondary structure from ordered to disordered. The molecular docking results showed that XY had different binding sites to α- and κ-CN, with several amino acids involved in the binding processes.

Application of Molecular Nanoprobes in the Analysis of Differentially Expressed Genes and Prognostic Models of Primary Hepatocellular Carcinoma.

Analyzing hub genes related to tumorigenesis based on biological big data has recently become a hotspot in biomedicine. Nanoprobes, nanobodies and theranostic molecules targeting hub genes delivered by nanocarriers have been widely applied in tumor theranostics. Hepatocellular carcinoma (HCC) is one of the most common cancers, with a poor prognosis and high mortality. Identifying hub genes according to the gene expression levels and constructing prognostic signatures related to the onset and outcome of HCC will be of great significance. In this study, the expression profiles of HCC and normal tissue were obtained from the GEO database and analyzed by GEO2R to identify DEGs. GO terms and KEGG pathways were enriched in DAVID software. The STRING database was consulted to find protein-protein interactions between proteins encoded by the DEGs, which were visualized by Cytoscape. Then, overall survival associated with the hub genes was calculated by the Kaplan-Meier plotter online tool, and verification of the results was carried out on TCGA samples and their corresponding clinical information. A total of 603 DEGs were obtained, of which 479 were upregulated and 124 were downregulated. PPI networks including 603 DEGs and 18 clusters were constructed, of which 7 clusters with MCODE score ≥3 and nodes ≥5 were selected. The 5 genes with the highest degrees of connectivity were identified as hub genes, and a prognostic model was constructed. The expression and prognostic potential of this model was validated on TCGA clinical data. In conclusion, a five-gene signature (TOP2A, PCNA, AURKA, CDC20, CCNB2) overexpressed inHCC was identified, and a prognostic model was constructed. This gene signature may act as a prognostic model for HCC and provide potential targets of nanotechnology.

Dissolving microneedles for transdermal delivery of huperzine A for the treatment of Alzheimer's disease.

Increasingly attention has been paid to the transdermal drug delivery systems with microneedles owing to their excellent compliance, high efficiency, and controllable drug release, therefore, become promising alternative with tremendous advantages for delivering specific drugs such as huperzine A (Hup A) for treatment of Alzheimer's disease (AD) yet with low oral bioavailability. The purpose of the present study is to design, prepare, and evaluate a dissolving microneedle patch (DMNP) as a transdermal delivery system for the Hup A, investigating its in vitro drug release profiles and in vivo pharmacokinetics as well as pharmacodynamics treating of AD. Skin penetration experiments and intradermal dissolution tests showed that the blank DMNP could successfully penetrate the skin with an adequate depth and could be quickly dissolved within 5 min. In vitro transdermal release tests exhibited that more than 80% of the Hup A was accumulatively permeated from DMNP through the skin within three days, indicating a sustained release profile. In vivo pharmacokinetic analysis demonstrated that the DMNP group resulted in longer T max (twofold), longer t 1/2 (fivefold), lower C max (3:4), and larger AUC(0-∞) (twofold), compared with the oral group at the same dose of Hup A. Pharmacodynamic research showed a significant improvement in cognitive function in AD rats treated with DMNP-Hup A and Oral-Hup A, as compared to the model group without treatment. Those results demonstrated that this predesigned DMNP is a promising alternative to deliver Hup A transdermally for the treatment of AD.

Quantitative lipidomics reveals alterations in donkey milk lipids according to lactation.

The composition of donkey milk is similar to that of human milk. However, the lipid content in donkey milk is lower than that in human milk. Thus far, the lipid composition of donkey milk during lactation has not been well-studied. Through mass spectroscopy-based quantitative lipidomics, we analyzed lipids in donkey colostrum (DC) and mature milk (DM). Thirteen subclasses of 335 lipids were identified in both DC and DM; 60 lipids - 17 upregulated and 43 downregulated - were differentially regulated between DM and DC (Variable Importance in Projection >1, P < 0.05), demonstrating that lipid composition changed with lactation. These different lipids were involved in 19 metabolic pathways, of which glycerophospholipid, linoleic acid, alpha-linolenic acid, glycosylphosphatidylinositol-anchor, glycerolipid, and arachidonic acid metabolism were the most relevant. Our results provide insights into quantitative alterations in donkey milk lipids during lactation, development of donkey milk products, and screening of potential biomarkers.