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Nano Letters Apr 2024Metal ions play a dual role in biological systems. Although they actively participate in vital life processes, they may contribute to protein aggregation and misfolding...
Metal ions play a dual role in biological systems. Although they actively participate in vital life processes, they may contribute to protein aggregation and misfolding and thus contribute to development of diseases and other pathologies. In nanofabrication, metal ions mediate the formation of nanostructures with diverse properties. Here, we investigated the self-assembly of α-lactalbumin into nanotubes induced by coordination with metal ions, screened among the series Mn, Co, Ni, Zn, Cd, and Au. Our results revealed that the affinity of metal ions toward hydrolyzed α-lactalbumin peptides not only impacts the kinetics of nanotube formation but also influences their length and rigidity. These findings expand our understanding of supramolecular assembly processes in protein-based materials and pave the way for designing novel materials such as metallogels in biochip and biosensor applications.
PubMed: 38598498
DOI: 10.1021/acs.nanolett.4c00601 -
Journal of Agricultural and Food... Apr 2024The gut barrier plays an important role in health maintenance by preventing the invasion of dietary pathogens and toxins. Disruption of the gut barrier can cause severe... (Review)
Review
The gut barrier plays an important role in health maintenance by preventing the invasion of dietary pathogens and toxins. Disruption of the gut barrier can cause severe intestinal inflammation. As a natural source, milk is enriched with many active constituents that contribute to numerous beneficial functions, including immune regulation. These components collectively serve as a shield for the gut barrier, protecting against various threats such as biological, chemical, mechanical, and immunological threats. This comprehensive review delves into the active ingredients in milk, encompassing casein, α-lactalbumin, β-lactoglobulin, lactoferrin, the milk fat globular membrane, lactose, transforming growth factor, and glycopeptides. The primary focus is to elucidate their impact on the integrity and function of the gut barrier. Furthermore, the implications of different processing methods of dairy products on the gut barrier protection are discussed. In conclusion, this study aimed to underscore the vital role of milk and dairy products in sustaining gut barrier health, potentially contributing to broader perspectives in nutritional sciences and public health.
Topics: Animals; Milk; Caseins; Lactalbumin; Lactoglobulins; Diet
PubMed: 38588092
DOI: 10.1021/acs.jafc.3c06861 -
The Journal of Dairy Research Feb 2024The protein composition in goat milk undergoes changes throughout the different lactation periods, displaying distinct characteristics that are influenced by the dynamic...
The protein composition in goat milk undergoes changes throughout the different lactation periods, displaying distinct characteristics that are influenced by the dynamic nature of protein composition and concentration during the transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Saanen goats during the colostral phase and the first month of lactation, 110 milk samples from 11 healthy mammary halves of seven Saanen goats were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The biuret method determined total protein concentration, and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis. Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing throughout the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred 5 or 7 d postpartum.
Topics: Animals; Goats; Colostrum; Female; Lactation; Whey Proteins; Milk; Mammary Glands, Animal; Milk Proteins; Postpartum Period
PubMed: 38584304
DOI: 10.1017/S002202992400013X -
Chembiochem : a European Journal of... Jun 2024Detailed insights into protein structure/function relationships require robust characterization methodologies. Free-solution capillary electrophoresis (CE) is a unique...
Detailed insights into protein structure/function relationships require robust characterization methodologies. Free-solution capillary electrophoresis (CE) is a unique separation technique which is sensitive to the conformation and/or composition of proteins, and therefore provides information on the heterogeneity of these properties. Three unrelated, conformationally/compositionally-altered proteins were separated by CE. An electrophoretic mobility distribution was determined for each protein along with its conformational and/or compositional heterogeneity. The CE results were compared with molar mass distributions obtained from size-exclusion chromatography coupled to light scattering (SEC-MALS). Bovine serum albumin multimers and two monomeric species were separated, highlighting variations in conformational/compositional heterogeneity among the multimers. Analysis of yeast alcohol dehydrogenase resolved two monomeric conformers and various tetrameric species, illustrating the impact of zinc ion removal and disulfide bond reduction on the protein's heterogeneity. The apo (calcium-free) and holo forms of bovine α-lactalbumin were separated and differences in the species' heterogeneity were measured; by contrast, the SEC-MALS profiles were identical. Comparative analysis of these structurally unrelated proteins provided novel insights into the interplay between molar mass and conformational/compositional heterogeneity. Overall, this study expands the utility of CE by demonstrating its capacity to discern protein species and their heterogeneity, properties which are not readily accessible by other analytical techniques.
Topics: Electrophoresis, Capillary; Cattle; Animals; Protein Conformation; Alcohol Dehydrogenase; Serum Albumin, Bovine; Lactalbumin
PubMed: 38567504
DOI: 10.1002/cbic.202400108 -
Foods (Basel, Switzerland) Mar 2024A strong correlation between the occurrence of various pathological conditions and intestinal dysbiosis is supported by a range of strong evidence. Vice versa, many... (Review)
Review
A strong correlation between the occurrence of various pathological conditions and intestinal dysbiosis is supported by a range of strong evidence. Vice versa, many pathologies have been shown, in turn, to be responsible for alterations in the gut microbiota, a condition that can worsen illness outcomes and response to therapies. For these reasons, great efforts have been made, and studies are still ongoing, to elucidate the mechanisms underlying gut microbiota alterations and to search for pharmacologic or other strategies that can effectively restore the gut microbiota. In this narrative review, we examined the most significant literature on the role of some milk bioactive compounds, such as milk oligosaccharides and whey proteins, in modulating the composition of the gut microbiota and the underlying mechanisms of action, with the aim of investigating the impact of the microbiota changes mediated by these milk bioactive molecules on human health, and their potential use as therapeutics to treat or adjuvate the treatment of gut dysbiosis and associated pathologies.
PubMed: 38540897
DOI: 10.3390/foods13060907 -
Journal of Oral Biology and... 2024Alpha-lactalbumin, the protein from human and bovine milk has been found to be promising as an alternative of anticancer agent This study was aimed to investigate the...
OBJECTIVES
Alpha-lactalbumin, the protein from human and bovine milk has been found to be promising as an alternative of anticancer agent This study was aimed to investigate the effects of lactalbumin enzymatic hydrolysate (LAH) on cell proliferation, migration, and mRNA expression of () on human squamous cell carcinoma (hSCC) cell lines, .
METHODS
Tongue (HSC-4 and 7) and pharyngeal (HN-30 and 31) hSCC cell lines were treated with a two-fold dilution of LAH (0.39-100 mg/ml). Cell viability and cell proliferation were examined by MTT assay. Colony forming unit (CFU) was assessed by crystal violet blue staining. Cell migration was investigated by scratch wound healing assay. Gene expression of metastasis-associated was assessed by RT-qPCR. Statistical analyses were evaluated at value = 0.05.
RESULTS
LAH at concentration of 50 and 100 mg/ml exhibited cytotoxicity on hSCC cells. The proliferation and CFU ability of hSCC cells were significantly attenuated after LAH treatment. The mRNA expression of , , and was reduced in HN-30 and HN-31 cells while expression of and was downregulated in HSC-7 cells. Only mRNA level was reduced in HSC-4 cells. However, cell migration of all hSCC cell lines did not alter after LAH treatment.
CONCLUSION
LAH treatment exhibits inhibitory effects on hSCC cell growth, proliferation and gene expression. Thus, LAH should be the promising alternative agent to develop the prospective anti-cancer drug.
PubMed: 38495954
DOI: 10.1016/j.jobcr.2024.02.011 -
Journal of Dairy Science Mar 2024Whole milk powder (WMP) manufactured in New Zealand in 1907 was sent to the Antarctic continent with the Shackleton-led British Antarctic Expedition from 1907 to 1909....
Whole milk powder (WMP) manufactured in New Zealand in 1907 was sent to the Antarctic continent with the Shackleton-led British Antarctic Expedition from 1907 to 1909. This powder was stored at ambient conditions at Shackleton's Hut at Cape Royds, Antarctica, for over 100 yr before a sample was collected on behalf of Fonterra by the Antarctic Heritage Trust. Having spent most of its existence both dried and in frozen storage, any deleterious reactions within the WMP would have been markedly retarded. The composition and some properties of the roller-dried Shackleton's WMP are reported along with those of 2 modern spray-dried New Zealand WMP. The Shackleton powder was less white and more yellow than the modern WMP and was composed of flakes rather than agglomerated particles, consistent with that expected of a roller-dried powder. Headspace analysis showed lipolytic and oxidative volatile compounds were present in the Shackleton WMP, indicting some deterioration of the milk either before powder manufacture or on storage of the finished product. On a moisture-free basis, the Shackleton WMP had higher protein, higher fat (with a markedly higher free fat level), higher ash, and a lower lactose level than the modern WMP. The lysine level was lower in the Shackleton WMP compared with the spray-dried powders, whereas the fatty acid composition was relatively similar. The sodium level was markedly higher in the Shackleton WMP compared with the spray-dried powder, which is probably due to the addition of an alkaline sodium salt to adjust the pH of the milk before roller drying. Lead, iron, and tin levels were markedly higher in the Shackleton WMP compared with the spray-dried powders, possibly due to the equipment used in powder manufacture and the tin-plated cases used for storage. The proteins in the Shackleton WMP were more lactosylated than in the spray-dried powders. The Shackleton WMP had a higher ratio of κ-casein A to B variants and a higher ratio of β-lactoglobulin B to A variants than the spray-dried powders, whereas the α-casein, β-casein, α-casein, and α-lactalbumin protein variants were similar in all powders. The total phospholipid content was markedly lower in the Shackleton WMP than the spray-dried powders, primarily due to a lower phosphatidylethanolamine concentration. The molecular species distributions within the phospholipid classes were generally similar in the 3 powders. Claims are sometimes encountered that the milk of today is different from that consumed by previous generations. However, this comparative study has shown that the Shackleton WMP was generally similar to modern WMP. Although differences in some components and properties were observed, these were attributable to the manufacturing equipment and processes used in the pioneering years of WMP manufacture.
Topics: Animals; Milk; Powders; Ice; Tin; Caseins; Phospholipids; Sodium
PubMed: 38423728
DOI: 10.3168/jds.2023-23893 -
Frontiers in Bioengineering and... 2024The demand for alternative sources of food proteins is increasing due to the limitations and challenges associated with conventional food production. Advances in...
The demand for alternative sources of food proteins is increasing due to the limitations and challenges associated with conventional food production. Advances in biotechnology have enabled the production of proteins using microorganisms, thus prompting the exploration of attractive microbial hosts capable of producing functional proteins in high titers. is widely used in industry for the production of amino acids and has many advantages as a host organism for recombinant protein production. However, its performance in this area is limited by low yields of target proteins and high levels of native protein secretion. Despite representing a challenge for heterologous protein production, the secretome has not been fully characterized. In this study, state-of-the-art mass spectrometry-based proteomics was used to identify and analyze the proteins secreted by . Both the wild-type strain and a strain that produced and secreted a recombinant β-lactoglobulin protein were analyzed. A total of 427 proteins were identified in the culture supernatants, with 148 predicted to possess a secretion signal peptide. MS-based proteomics on the secretome enabled a comprehensive characterization and quantification (based on abundance) of the secreted proteins through label-free quantification (LFQ). The top 12 most abundant proteins accounted for almost 80% of the secretome. These are uncharacterized proteins of unknown function, resuscitation promoting factors, protein PS1, Porin B, ABC-type transporter protein and hypothetical membrane protein. The data can be leveraged for protein production by, e.g., utilizing the signal peptides of the most abundant proteins to improve secretion of heterologous proteins. In addition, secretory stress can potentially be alleviated by inactivating non-essential secreted proteins. Here we provide targets by identifying the most abundant, secreted proteins of which majority are of unknown function. The data from this study can thus provide valuable insight for researchers looking to improve protein secretion and optimize as a host for secretory protein production.
PubMed: 38415189
DOI: 10.3389/fbioe.2024.1348184 -
Animals : An Open Access Journal From... Feb 2024Prolactin is essential for mammary gland development and lactation. Progesterone also induces ductal branching and alveolar formation via initial secretory...
Prolactin is essential for mammary gland development and lactation. Progesterone also induces ductal branching and alveolar formation via initial secretory differentiation within the mammary gland. Herein, we aimed to evaluate the role of progesterone as a prolactin substitute for the production of cell-cultured milk components in MAC-T cells. Cells were treated with various hormones such as prolactin (PRL), progesterone (P4), 17β-estradiol (E2), cortisol (COR), and insulin (INS) for 5 d. MAC-T cells cultured in a P4 differentiation media (2500 ng/mL of P4, 25 ng/mL of E2, 25 ng/mL of COR, and 25 ng/mL of INS) showed similar levels of E74-like factor 5 (Elf5) and milk component synthesis (-casein, -casein, -lactalbumin, β-lactoglobulin, and triglycerides) compared to those cultured in a PRL differentiation media (5000 ng/mL of PRL, 500 ng/mL of CORT, and 50 ng/mL of INS). The levels of -casein and triglycerides in the optimal P4 differentiation media were present at comparable levels to those in the PRL differentiation media. Our results demonstrated that P4 induces the activation of Elf5 and the synthesis of milk components in MAC-T cells, similar to PRL. Therefore, P4 may be used as an effective substitute of PRL for cell-cultured milk production in in vitro frameworks.
PubMed: 38396610
DOI: 10.3390/ani14040642 -
Scientific Reports Feb 2024Though new targeted therapies for colorectal cancer, which progresses from local intestinal tumors to metastatic disease, are being developed, tumor specificity remains...
Though new targeted therapies for colorectal cancer, which progresses from local intestinal tumors to metastatic disease, are being developed, tumor specificity remains an important problem, and side effects a major concern. Here, we show that the protein-fatty acid complex BAMLET (bovine alpha-lactalbumin made lethal to tumor cells) can act as a peroral treatment for colorectal cancer. Apc mice, which carry mutations relevant to hereditary and sporadic human colorectal cancer, that received BAMLET in the drinking water showed long-term protection against tumor development and decreased expression of tumor growth-, migration-, metastasis- and angiogenesis-related genes. BAMLET treatment via drinking water inhibited the Wnt/β-catenin and PD-1 signaling pathways and prolonged survival without evidence of toxicity. Systemic disease in the lungs, livers, spleens, and kidneys, which accompanied tumor progression, was inhibited by BAMLET treatment. The metabolic response to BAMLET included carbohydrate and lipid metabolism, which were inhibited in tumor prone Apc mice and weakly regulated in C57BL/6 mice, suggesting potential health benefits of peroral BAMLET administration in addition to the potent antitumor effects. Together, these findings suggest that BAMLET administration in the drinking water maintains antitumor pressure by removing emergent cancer cells and reprogramming gene expression in intestinal and extra-intestinal tissues.
Topics: Mice; Humans; Animals; Cattle; Drinking Water; Mice, Inbred C57BL; Signal Transduction; Colorectal Neoplasms; beta Catenin
PubMed: 38360830
DOI: 10.1038/s41598-024-54040-w