The mode of actions of lysozyme as an immunoglobulin production stimulating factor

Effects of Dietary Supplementation of Essential Oils, Lysozyme, and Vitamins' Blend on Layer Hen Performance, Viral Vaccinal Response, and Egg Quality Characteristics

Maintaining respiratory tract health is crucial for layers, impacting gut health, laying performance, and egg quality. Viral diseases and standard vaccinations can compromise tracheal epithelium function, leading to oxidative stress. This study assessed the impact of a blend of feed additives, predominantly lysozyme (L), essential oils (EO), and vitamins (VIT) (referred to as L + EO + VIT), on young layers during an oral vaccination schedule. The supplementation significantly enhanced antibody titers for Newcastle Disease Virus (NDV) and Infectious Bronchitis Virus (IBV) after vaccination, trachea functionality and intestinal health in the jejunum, increased egg production, and exhibited a trend toward higher egg weight. Although feed intake showed no significant difference, egg quality remained consistent across experimental groups. Moreover, L + EO + VIT supplementation elevated total phenolic content in eggs, improving oxidative stability in both fresh and stored eggs, particularly under iron-induced oxidation. Notably, it substantially reduced yolk lipid peroxidation and albumen protein carbonyls. In conclusion, water supplementation with L + EO + VIT may enhance humoral immune response to IBV and NDV, positively impacting hen productivity. These findings indicate improved tracheal function and enhanced oxidative stability, emphasizing the potential of this blend in promoting overall health and performance in layers.

Adsorption of conjugates of lysozyme and fluorescein isothiocyanate in hydrophobic interaction chromatography

Bioconjugates, such as antibody-drug conjugates or fluorescent-labeled proteins, are highly interesting for various applications in medicine and biology. In their production, not only the synthesis is challenging but also the downstream processing, for which hydrophobic interaction chromatography (HIC) is often used. However, in-depth studies of the adsorption of bioconjugates in HIC are still rare. Therefore, in the present work, three different conjugates of lysozyme and fluorescein isothiocyanate (FITC) were synthesized and isolated, and their adsorption on the hydrophobic resin Toyopearl PPG-600 M was systematically studied in batch experiments. The influence of sodium chloride and ammonium sulfate with ionic strengths up to 2000 mM on the adsorption isotherms was investigated at pH 7.0 and 25 °C, and the results were compared to those for pure lysozyme. The conjugation leads to an increase of the adsorption in all studied cases. All studied conjugates contain only a single FITC and differ only in the position of the conjugation on the lysozyme. Despite this, strong differences in the adsorption behavior were observed. Moreover, a mathematical model was developed, which enables the prediction of the adsorption isotherms in the studied systems for varying ionic strengths.

Hen Egg Lysozyme Alleviates Static Mechanical Pain Via NRF1-Parkin-TACAN Signaling Axis in Sensory Neurons

Mechanical allodynia impinges on the life quality of patients. Hen Egg Lysozyme (HEL) is a substance extracted from eggs that is commonly used to inhibit bacterial activity. The role of HEL in regulating and treating pain is unclear. Here, we find that HEL selectively attenuates static mechanical allodynia of mice induced by complete Freund's adjuvant (CFA), spinal nerve ligation (SNL) and chemotherapeutic agent. RNA-seq screening reveals that CFA significantly reduces the expression of Parkin in dorsal root ganglion (DRG) neurons of mice, while pre-administration of HEL increases the expression of Parkin and remits the static mechanical allodynia induced by Parkin-siRNA. Moreover, HEL increases the interaction between nuclear respiratory factor 1 (NRF1) and histone acetyltransferase P300 and then enhances the NRF1 mediated histone acetylation in prkn promoter region in DRGs of mice. Further, Parkin interacts with mechanotransducing ion channel TACAN (Tmem120a) and knockdown of Parkin significantly increases the membrane trafficking of TACAN in sensory neurons of mice. While pre-administration of HEL inhibits the increased membrane trafficking of TACAN in sensory neurons of mice induced by Parkin-siRNA. In addition, pre-given of HEL also significantly attenuates the static mechanical allodynia induced by overexpression of TACAN in mice, and the effect of HEL can be blocked by Parkin-siRNA. This indicates that HEL increases the expression of Parkin through epigenetic mechanisms and then decreases TACAN membrane trafficking in sensory neurons to relieve static mechanical hypersensitivity. Therefore, we reveal a novel function of HEL, which is a potential substance for the treatment of static mechanical pain.

Dairy-Derived and Egg White Proteins in Enhancing Immune System Against COVID-19

Coronavirus disease (COVID-19) is a global health challenge, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) triggers a plethora of respiratory disturbances and even multiple organs failure that can be fatal. Nutritional intervention is one of the key components toward to a proper management of COVID-19 patients, especially in those requiring medication, and should thus be considered the first-line treatment. Immuno-modulation and -stimulation are currently being explored in COVID-19 management and are gaining interest by food and pharmaceutical industries. Various dietary combinations, bioactive components, nutrients and fortified foods have been reported to modulate inflammation during disease progression. Dietary combinations of dairy-derived products and eggs are gaining an increasing attention given the huge immunomodulatory and anti-inflammatory properties attributed to some of their chemical constituents. Eggs are complex dietary components containing many essential nutrients and bioactive compounds as well as a high-quality proteins. Similarly, yogurts can replenish beneficial bacteria and contains macronutrients capable of stimulating immunity by enhancing cell immunity, reducing oxidative stress, neutralizing inflammation and regulating the intestinal barriers and gut microbiome. Thus, this review highlights the impact of nutritional intervention on COVID-19 management, focusing on the immunomodulatory and inflammatory effects of immune-enhancing nutrients.

Plasma treatment causes structural modifications in lysozyme, and increases cytotoxicity towards cancer cells

Bacterial and mammalian proteins, such as lysozyme, are gaining increasing interest as anticancer drugs. This study aims to modify the lysozyme structure using cold atmospheric plasma to boost its cancer cell killing effect. We investigated the structure at acidic and neutral pH using various experimental techniques (circular dichroism, fluorescence, and mass spectrometry) and molecular dynamics simulations. The controlled structural modification of lysozyme at neutral pH enhances its activity, while the activity was lost at acidic pH at the same treatment conditions. Indeed, a larger number of amino acids were oxidized at acidic pH after plasma treatment, which results in a greater distortion of the lysozyme structure, whereas only limited structural changes were observed in lysozyme after plasma treatment at neutral pH. We found that the plasma-treated lysozyme significantly induced apoptosis to the cancer cells. Our results reveal that plasma-treated lysozyme could have potential as a new cancer cell killing drug.

Facile modification of polycaprolactone nanofibers with egg white protein

Synthetic polymers remain to be a major choice for scaffold fabrication due to their structural stability and mechanical strength. However, the lack of functional moieties limits their application for cell-based therapies which necessitate modification and functionalization. Blending synthetic polymers with natural components is a simple and effective way to achieve the desired biological properties for a scaffold. Herein, nanofibrous mats made of polycaprolactone (PCL) and egg white protein (EWP) blend were developed and further evaluated for use as a scaffold for tissue engineering applications. Homogeneous distribution of EWP was achieved throughout the nanofibrous mats, as shown by immunohistochemistry. ATR-FTIR analysis and contact angle measurements have further confirmed the presence of EWP on the surface of the samples. The swelling test showed that PCL/EWP nanofibers have higher water uptake than PCL nanofibrous mats. Also, EWP addition on the nanofibrous mats resulted in an increase in the tensile strength and Young's modulus of the mats, indicating that the presence of protein can greatly enhance the mechanical properties of the mats. A significantly higher, more uniform, and dispersed cell spreading was observed on days 7 and 14 than that on neat PCL mats, demonstrating the importance of providing the required cues for cell homing by the availability of EWP. Hence, EWP is shown to be a simple and low-cost source for the functionalization of PCL nanofibrous mats. EWP is, therefore, a facile candidate to enhance cellular interactions of synthetic polymers for a wide range of tissue engineering applications.

Anticancer and immunomodulatory activity of egg proteins and peptides: a review

Eggs are widely recognized as a highly nutritious food source that offer specific health benefits for humans. Eggs contain all of the proteins, lipids, vitamins, minerals, and growth factors necessary for embryonic development. In particular, egg white and yolk proteins are considered functional food substances because they possess biological activities such as antimicrobial, antioxidant, metal-chelating, antihypertensive, anticancer, and immunomodulatory activities. Peptides produced via processes such as enzymatic hydrolysis, fermentation by microorganisms, and some chemical and physical treatments of egg proteins have been shown to enhance the functional properties and solubility of these peptides. Peptide activity is strongly related to amino acid sequence, composition, and length. At present, cancer remains among the leading causes of mortality worldwide, and therefore research aimed at developing new treatments for cancer immunotherapy is of great interest. The present review focuses primarily on the anticancer and immunomodulatory activities of egg proteins and their peptides and provides some insight into their underlying mechanisms of action. A number of egg proteins and peptides have been reported to induce apoptosis in cancer cells, protect against DNA damage, decrease the invasion ability of cancer cells, and exhibit cytotoxic and antimutagenic activity in various cancer cell lines. Furthermore, egg proteins and peptides can stimulate or suppress pro- or anti-inflammatory cytokines, as well as affect the production of inflammatory mediators in a variety of cell lines. In addition, the composition of eggs and the processes of egg proteins and peptides production will be discussed.

Bioactive Egg Proteins

The nutritional excellence of chicken egg is derived from its task as a life-giving medium, supplying the necessary nutrients to the hen's embryo while protecting it from external threats. Additionally, egg proteins possess unique biological activities above and beyond their known functional and nutritional roles. In the last few decades, extensive research has been done to evaluate the various biological activities of egg proteins and protein-derived peptides. Egg proteins and protein-derived peptides have been attributed to diverse biological activities, the most well-known being their antimicrobial properties. However, egg proteins and peptides have been shown to have other biological activities, such as antihypertensive, antioxidant, anticancer, immunomodulatory, and protease inhibitory activity. Egg-derived bioactive proteins have had a relevant scientific impact and exhibit promising applicability as an ingredient for the development of functional foods and nutraceuticals. However, it is critical to understand the effects of these proteins in signaling pathways to delineate their molecular mechanisms of action. Further studies are required to fill the current knowledge gaps. Therefore, the purpose of the chapter is to illustrate the present knowledge of the bioactivity of different egg proteins and their physiological effects.

Lysozyme from hen egg white ameliorates lipopolysaccharide-induced systemic inflammation in mice

Lysozyme is an anti-bacterial protein that is widely distributed in nature. Our previous studies revealed that lysozyme shows anti-inflammatory effect on hyperinflammatory macrophages in vitro. The effect of lysozyme on lipopolysaccharide-induced inflammation model mice was examined in this study. Oral administration of lysozyme at 2250 mg/kg body weight/day (high-dose group) significantly suppressed interleukin (IL)-6 and tumor necrosis factor-α levels in the serum. IL-6 level in the spleen was significantly suppressed by lysozyme at 450 mg/kg body weight/day (middle-dose group) and high-dose group due to the suppression of gene expression level. The gene expression levels of IL-1β and IL-12 were also decreased by lysozyme in the high-dose group. In addition, lysozyme significantly suppressed IL-6 level in the liver in the high-dose group. Our findings suggest that lysozyme mitigates inflammatory condition in vivo by suppressing inflammatory cytokine levels in serum and organs from LPS-induced inflammation model mice.

Anti-inflammatory effect of lysozyme from hen egg white on mouse peritoneal macrophages

Lysozyme from hen egg has been reported to possess an anti-inflammatory effect. However, little is known about its detailed mechanism. The mechanism of anti-inflammatory effect of lysozyme was examined in this study. When mouse macrophage-like cell line RAW264.7 cells and mouse peritoneal macrophages were activated with lipopolysaccharide (LPS) and then treated with lysozyme, the production of tumor necrosis factor-α and interleukin-6 was significantly suppressed. The effect was induced by suppressing the gene expression levels of both cytokines. Phagocytosis activity of peritoneal macrophages was not altered by the treatment with lysozyme, suggesting that lysozyme shows the anti-inflammatory effect without inhibiting the phagocytotic response of macrophages. In addition, lysozyme inhibited phosphorylation of c-jun N-terminal kinase (JNK) and was taken up by macrophages within 1 h after treatment of the cells with lysozyme. Overall results suggest that lysozyme is taken up intracellularly and suppresses LPS-induced inflammatory responses by inhibiting JNK phosphorylation.

Hyphenated Analytical Methods in Determination of Biologically Active Compounds in Hen's Eggs

Hen's egg is a complete material needed for the development of the embryo; it is an important source of nutraceutical compounds, such as protein, fats, vitamins, trace metals, and minerals. Moreover, avian egg contains biologically active compounds that exhibit antibacterial and antimicrobial activities as well as antitumor, antiviral, antioxidant, immunomodulating, and therapeutic properties. Eggs are mostly very good sources of valuable, easily digestible proteins. This review focuses on the biologically active compounds from hen's egg and applications of these compounds in medicine and the pharmaceutical industry. Additionally, it gives an overview of the hyphenated separation techniques, including sample preparation, analysis, and identification, used in the proteomics and lipidomics analysis.

Bioactive peptides from egg: a review

Purpose

– The aim of the article was to focus on various peptides identified in the egg and their probable application as novel ingredients in the development of functional food products. Bioactive peptides of egg origin have attracted increasing interest as one of the prominent candidates for development of various health-promoting functional and designer foods.

Design/methodology/approach

– Traditionally known as a source of highly valuable proteins in human nutrition, eggs are nowadays also considered as an important source of many bioactive peptides which may find wide application in medicine and food production. These specific protein fragments from egg proteins which, above and beyond their nutritional capabilities, have a positive impact on the body’s function or condition by affecting the digestive, endocrine, cardiovascular, immune and nervous systems, and may ultimately influence health.

Findings

– Several peptides that are released in vitro or in vivo from egg proteins have been attributed to different health effects, including antihypertensive effects, antimicrobial properties, antioxidant activities, anticancer activity, immunomodulating activity, antiadhesive properties and enhancement of nutrient absorption and/or bioavailability. Extensive research has been undertaken to identify and characterize these biologically active peptides of egg origin which has changed the image of egg as a new source of biologically active ingredients for the development of functional foods with specific benefits for human health and treatment and prevention of diseases.

Originality/value

– The paper mainly describes the above-stated properties of bioactive peptides derived from egg proteins.

Immunostimulation Effect of Jellyfish Collagen

Certain edible large jellyfishes belonging to the order Rhizostomeae are consumed in large quantities in China and Japan. The exumbrella part of the edible jellyfish Stomolophus nomurai was cut and soaked in dilute hydrochloric acid solution (pH 3.0) for 12 h, and heated at 121 degrees C for 20 min. The immunostimulation effects of the jellyfish extract were examined. The jellyfish extract enhanced IgM production of human hybridoma HB4C5 cells 34-fold. IgM and IgG production of human peripheral blood lymphocytes (PBL) were also accelerated, 2.8- and 1.4-fold respectively. Moreover, production of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha by human PBL was stimulated 100- and 17-fold respectively. Collagenase treatment inactivated the immunostimulation activity of the jellyfish extract. In addition, purified collagen from bovine Achilles' tendon accelerated IgM production of hybridoma cells. These facts mean that collagen has an immunostimulation effect, and that the active substance in jellyfish extract is collagen.

Immunostimulatory effects of collagen from jellyfish in vivo

We focused on the biological activity of the collagen extracts obtained from the giant edible jellyfish, Nemopilema nomurai. Jellyfish collagen extracts stimulates the production of immunoglobulins (Igs) and cytokines by human hybridoma cells and human peripheral blood lymphocytes. Therefore, we examined the immunoregulatory function of jellyfish collagen extracts in mice. Intake of jellyfish collagen extracts facilitated the Ig production activity of lymphocytes from spleen and Peyer's patch. Furthermore, the levels of Igs in the serum clearly increased after the administration of jellyfish collagen extracts. Intake of bovine collagen from Achilles' tendon also activated lymphocytes activity in mice. The activity of total and antigen-specific Ig production in splenocytes from OVA-challenged mice was also enhanced by collagen intake. However, the total and OVA-specific IgE levels in the serum were not affected by the collagen intake. These results suggested that jellyfish collagen extracts stimulates an immune response in vivo, without inducing allergic complications.

Chronic caffeine intake affects lysozyme activity and immune cells in mice

The aim of this study was to examine the effect of caffeine on the activity of lysozyme and some immune parameters of mice. The mice were divided into five groups. Group 1, the control group, was given water. The other four groups were administered various concentrations of caffeine by oral intubation (group 2, 2 mg kg−1; group 3, 20 mg kg−1; group 4, 40 mg kg−1; group 5, 200 mg kg−1). It was found that the activity of lysozyme in the serum depended on the caffeine dose. Compared with the control (group 1), lysozyme activity was 1.4-times higher in group 2, 1.6-times higher in the group 3, and 1.8-times higher in groups 4 and 5 (P < 0.05). In group 3 a significant increase in spleen weight was detected and the spleen index was 2.1-times (P < 0.05) higher compared with control. In group 3 the number of monocytes and neutrophils was 2.5-times higher (P < 0.05) compared with control. In group 5 the caffeine increased the number of neutrophils 2.7-times and increased the number of eosinophils 4.6-times (P < 0.05) compared with control. Our study revealed that caffeine played an important role in the development of protective immune response.

Mode of action of the immunostimulatory effect of collagen from jellyfish

We have previously demonstrated that collagen from jellyfish simulated immunoglobulin and cytokine production by human-human hybridoma line HB4C5 cells and by human peripheral blood lymphocytes (hPBL). The mode of action of the collagen as an immunostimulatory factor was investigated. The expression levels of immunoglobulin mRNAs in HB4C5 cells, and those of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and transforming growth factor (TGF)-beta in hPBL were up-regulated by jellyfish collagen. In addition, this collagen activated IgM production by transcription-suppressed HB4C5 cells that had been treated with actinomycin D. This collagen also enhanced IgM production by translation-suppressed HB4C5 cells that had been treated with sodium fluoride, but was ineffective in accelerating IgM production by HB4C5 cells treated with cycloheximide. Moreover, the intracellular IgM level in HB4C5 cells treated with the post-translation inhibitor, monensin, was increased by this collagen. These results suggest that collagen from jellyfish stimulated not only the transcription activity, but also the translation activity for enhanced immunoglobulin and cytokine production.

Immunostimulation effects of proteose-peptone component 3 fragment on human hybridomas and peripheral blood lymphocytes

Fat-free bovine milk fermented by 12 kinds of lactic acid bacteria and yeast enhanced monoclonal antibody production of human hybridoma HB4C5 cells 2.8-fold in serum-free medium. Immunoglobulin production of human peripheral blood lymphocytes (PBL) was also stimulated in vitro. IgM and IgG production of human PBL was accelerated up to 2.8-fold and 5.4-fold, respectively. Interferon-gamma production of human PBL was also accelerated 6.0-fold by 50 microg/ml of the fermented milk. However, interleukin-4 production of PBL was not affected, and tumor necrosis factor-alpha production was suppressed. The activity was enhanced 2.5-fold by the thermal treatment for 30 min at 65 degrees C and was completely lost by trypsin digestion. The findings suggested that the active substance in the fermented milk was heat stable protein. Gel-filtration and the SDS-PAGE analysis revealed that the molecular weight of the active substance was estimated as 19.0 kDa, which was not detected in fat-free bovine milk before fermentation. N-terminal amino acid sequence of the 19.0 kDa protein was highly homologous to proteose-peptone component 3 (PP3). Since molecular weight of PP3 is 28 kDa, it is suggested that the 19.0 kDa protein is derived from degradation of PP3 during fermentation of fat-free milk. Moreover, PP3 purified from fat-free milk also enhanced IgM production of HB4C5 cells.

Evidence for a bimodal relation between serum lysozyme and prognosis in 232 patients with acute myeloid leukaemia

Lysozyme values are sometimes used as an aid for diagnostic subtyping of acute myeloid leukaemia (AML), since monocytic forms often show high levels. We wanted to study if pretreatment serum lysozyme has any relation to prognosis in AML. For this purpose, 232 adult AML patients who had received remission induction therapy at two hospitals were reviewed retrospectively. Their median age was 65.5 yr. Sixty-three patients were FAB classified as "monocytic" AML (M4, M5) and 169 as "non-monocytic" AML (M0, M1, M2, M3, M6). A linear relation was rejected, and a bimodal relation was found between lysozyme and prognosis where values below 20 or above 80 mg L-1 were indicative of better outcome than values in the range 20-80 mg L-1. Analysed in three categories with cut-off levels at 20 and 80 mg L-1, lysozyme showed an independent effect on complete remission (CR) frequency (P = 0.0003), overall survival (P < 0.0001), and CR duration (P = 0.0005) in multivariate analysis. The hazard ratios (HR) for lysozyme <20, 20-80, and >80 mg L-1 regarding overall survival were 1.0, 3.3, and 0.7. Influence of lysozyme on survival was bimodal both in "non-monocytic" AML (HR 1.0, 3.0, and 0.1) and M4-M5 (HR 1.0, 10.1, and 1.2). Our finding of a bimodal relation between serum lysozyme and prognosis in AML should be regarded as a new hypothesis and controlled in other studies.

Nonspecific secretory immunity in HIV-infected patients with oral candidiasis

Buccal and digestive tract opportunistic infections occur frequently in patients infected by HIV. In this study, we measured lysozyme (Lz), lactoferrin (Lf), total IgA (T-IgA), and secretory IgA (S-IgA) levels to investigate nonspecific secretory immunity in HIV-infected patients with oral candidiasis. Serum, saliva, and stool samples were analyzed by time-resolved immunofluorometric assay for Lz and Lf levels and by enzyme-linked immunosorbent assay for T-IgA and S-IgA levels. Mean salivary Lf and T-IgA levels (66.50 mg/L and 0.10 g/L, respectively) and mean fecal Lf, T-IgA, and S-IgA outputs (0.87, 54.0, and 43.6 mg/d, respectively) were significantly higher in HIV-infected patients with oropharyngeal candidiasis than in HIV-infected patients without oropharyngeal candidiasis and healthy subjects. There was a modification in the molecular form rate, with a high increase in S-IgA and monomeric IgA transudation from the plasmatic compartment into salivary and digestive fluids and an increase in salivary Lf local synthesis by polymorphonuclear neutrophils. HIV infection appears to be associated with dysregulation of some of the nonspecific immune factors at the mucosal surface. Despite high saliva concentrations and high intestinal output, innate immunity was not able to stop yeast expansion in HIV-infected patients.

Heat denaturation enhanced immunoglobulin production stimulating activity of lysozyme from hen egg white

Lysozyme from hen egg white was identified as an immunoglobulin production stimulating factor (IPSF) that enhances immunoglobulin production by hybridomas and lymphocytes. The IPSF activity of lysozyme was facilitated by heat treatment. The heat treatment of lysozyme at 83 degrees C for 30 min activated its specific IPSF effect 30.0-fold compared with that of native lysozyme. The IPSF activity of lysozyme heat-treated at 83 degrees C in 4 M urea solution was enhanced 8.4-fold than that of native lysozyme. However, lysozyme that was not heated in 4 M urea solution completely lost its IPSF activity. This means that the IPSF activity of this enzyme in 4 M urea was reactivated by thermal treatment. Moreover, coexistence of 0.5 mM 2-mercaptoethanol (2-ME) during heating in 4 M urea solution extremely enhanced the IPSF activity up to 77.8-fold. The uptake of lysozyme by hybridoma cells was enhanced by heat denaturation in 4 M urea. The hydrophobicity of lysozyme was extremely increased by heat-treatment in 2-ME containing urea solution. It is expected from these findings that the increase in the hydrophobicity caused the enhancement of incorporation of lysozyme into target cells, and resulted in the acceleration of IgM production.

Increase of immunoglobulin productivity of human-human hybridoma HB4C5 cells by histone

A histone mixture (H1, H2A, H2B, H3, and H4) derived from calf thymus stimulated IgM production by human-human hybridoma HB4C5 cells. On the contrary, the histone mixture did not increase IgM production by the human Burkitt's lymphoma cell line NAT-30, IgG production by the human B lymphoblastoid cell line HMy-2, and IgE production by the human myeloma cell line U266. The immunoglobulin production-stimulating activity of the histone mixture was inactivated by trypsin or chymotrypsin digestion. In addition, confocal laser microscopic analysis had shown that HB4C5 cells incorporated a lot of histone but other cell lines did not incorporate it as much. These facts strongly suggest that histone acts as an immunoglobulin production-stimulating factor (IPSF) after internalization into the human B cell lines and the native structure of histone is required for the IPSF activity.

Use of proteomic methodology for the characterization of human milk fat globular membrane proteins

Characterization of the major human milk fat globular membrane proteins was carried out using proteomic techniques comprising two-dimensional polyacrylamide gel electrophoresis, followed by in situ PNGase F and trypsin digestion. Matrix-assisted laser desorption/ionization quadrupole time-of-flight and electrospray ionization mass spectrometry identified seven major protein components: alpha-lactalbumin, lysozyme precursor, beta-casein, clusterin, lactotransferrin, polymeric immunoglobulin receptor precursor, and human milk fat globule EGF-factor 8 protein. Sequence information on the protein-associated glycans was determined by matrix-assisted laser desorption-ionization quadrupole time-of-flight hybrid mass spectrometry. This glycan analysis revealed interesting fucosylation branching patterns which may be influential in maternal protection of the newborn against bacterial and viral pathogenic attack.