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1.
Int J Mol Sci ; 25(9)2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38731878

RESUMEN

ß-lactoglobulin (BLG) forms amyloid-like aggregates at high temperatures, low pH, and low ionic strengths. At a pH below 2, BLG undergoes hydrolysis into peptides, with N-terminal peptides 1-33 and 1-52 being prone to fibrillization, forming amyloid-like fibrils. Due to their good mechanical properties, BLG amyloids demonstrate great potential for diverse applications, including biosensors, nanocomposites, and catalysts. Consequently, further studies are essential to comprehensively understand the factors governing the formation of BLG amyloid-like morphologies. In this study, all-atom molecular dynamics simulations were employed to explore the aggregation of N-terminal 1-33 and 1-52 BLG peptides under conditions of pH 2 and at 10 mM NaCl concentration. The simulations revealed that the peptides spontaneously assembled into aggregates of varying sizes. The aggregation process was enabled by the low charge of peptides and the presence of hydrophobic residues within them. As the peptides associated into aggregates, there was a concurrent increase in ß-sheet structures and the establishment of hydrogen bonds, enhancing the stability of the aggregates. Notably, on average, 1-33 peptides formed larger aggregates compared to their 1-52 counterparts, while the latter exhibited a slightly higher content of ß-sheets and higher cluster orderliness. The applied approach facilitated insights into the early stages of amyloid-like aggregation and molecular-level insight into the formation of ß-sheets, which serve as nucleation points for further fibril growth.


Asunto(s)
Lactoglobulinas , Simulación de Dinámica Molecular , Agregado de Proteínas , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Interacciones Hidrofóbicas e Hidrofílicas , Enlace de Hidrógeno , Amiloide/química , Péptidos/química , Concentración de Iones de Hidrógeno , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo
2.
J Agric Food Chem ; 72(20): 11746-11758, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38718253

RESUMEN

A novel strategy combining ferulic acid and glucose was proposed to reduce ß-lactoglobulin (BLG) allergenicity and investigate whether the reduction in allergenicity was associated with gut microbiome and serum metabolism. As a result, the multistructure of BLG changed, and the modified BLG decreased significantly the contents of IgE, IgG, IgG1, and mMCP-1 in serum, improved the diversity and structural composition of gut microbiota, and increased the content of short-chain fatty acids (SCFAs) in allergic mice. Meanwhile, allergic mice induced by BLG affected arachidonic acid, tryptophan, and other metabolic pathways in serum, the modified BLG inhibited the production of metabolites in arachidonic acid metabolism pathway and significantly increased tryptophan metabolites, and this contribution helps in reducing BLG allergenicity. Overall, reduced allergenicity of BLG after ferulic acid was combined with glucose modification by regulating gut microbiota, the metabolic pathways of arachidonic acid and tryptophan. The results may offer new thoughts alleviating the allergy risk of allergenic proteins.


Asunto(s)
Alérgenos , Ácidos Cumáricos , Microbioma Gastrointestinal , Glucosa , Lactoglobulinas , Ácidos Cumáricos/metabolismo , Ácidos Cumáricos/química , Animales , Lactoglobulinas/inmunología , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Ratones , Humanos , Alérgenos/inmunología , Alérgenos/química , Alérgenos/metabolismo , Glucosa/metabolismo , Femenino , Bacterias/inmunología , Bacterias/metabolismo , Bacterias/clasificación , Bacterias/genética , Ratones Endogámicos BALB C , Inmunoglobulina E/inmunología , Inmunoglobulina E/sangre , Ácidos Grasos Volátiles/metabolismo , Bovinos , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Hipersensibilidad a la Leche/inmunología
3.
J Agric Food Chem ; 72(15): 8285-8303, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38588092

RESUMEN

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, ß-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.


Asunto(s)
Caseínas , Leche , Animales , Leche/metabolismo , Caseínas/metabolismo , Lactalbúmina/metabolismo , Lactoglobulinas/metabolismo , Dieta
4.
Chem Res Toxicol ; 37(5): 757-770, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38625865

RESUMEN

Per- and polyfluoroalkyl substances (PFAS) are known for their high environmental persistence and potential toxicity. The presence of PFAS has been reported in many dairy products. However, the mechanisms underlying the accumulation of PFAS in these products remain unclear. Here, we used native mass spectrometry and molecular dynamics simulations to probe the interactions between 19 PFAS of environmental concern and two isoforms of the major bovine whey protein ß-lactoglobulin (ß-LG). We observed that six of these PFAS bound to both protein isoforms with low- to mid-micromolar dissociation constants. Based on quantitative, competitive binding experiments with endogenous ligands, PFAS can bind orthosterically and preferentially to ß-LG's hydrophobic ligand-binding calyx. ß-Cyclodextrin can also suppress binding of PFAS to ß-LG owing to the ability of ß-cyclodextrin to directly sequester PFAS from solution. This research sheds light on PFAS-ß-LG binding, suggesting that such interactions could impact lipid-fatty acid transport in bovine mammary glands at high PFAS concentrations. Furthermore, our results highlight the potential use of ß-cyclodextrin in mitigating PFAS binding, providing insights toward the development of strategies to reduce PFAS accumulation in dairy products and other biological systems.


Asunto(s)
Fluorocarburos , Lactoglobulinas , Leche , Animales , Lactoglobulinas/metabolismo , Lactoglobulinas/química , Bovinos , Leche/química , Leche/metabolismo , Fluorocarburos/química , Fluorocarburos/metabolismo , Simulación de Dinámica Molecular , beta-Ciclodextrinas/química , beta-Ciclodextrinas/metabolismo , Sitios de Unión , Unión Proteica
5.
Colloids Surf B Biointerfaces ; 238: 113924, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38669751

RESUMEN

ß-lactoglobulin (BLG) is the major whey protein with negative charges at neutral pH in aqueous media. Thus, the interaction with mucins, the major polyanionic component of mucus, is very weak due to the electrostatic repulsion between them. The present study postulates that cationization of BLG molecules may reverse the interaction characteristics between BLG and mucin from repulsive to associative. To this end, cationic-modified BLGs were prepared by grafting positively charged ethylenediamine (EDA) moieties into the negatively charged carboxyl groups on the aspartic and glutamic acid residues and compared with non-modified BLG upon mixing with porcine gastric mucin (PGM). To characterize the structural and conformational features of PGM, non/cationized BLGs, and their mixtures, various spectroscopic approaches, including zeta potential, dynamic light scattering (DLS), and circular dichroism (CD) spectroscopy were employed. Importantly, we have taken surface adsorption with optical waveguide lightmode spectroscopy (OWLS), and tribological properties with pin-on-disk tribometry at the sliding interface as the key approaches to determine the interaction nature between them as mixing PGM with polycations can lead to synergistic lubrication at the nonpolar substrate in neutral aqueous media as a result of an electrostatic association. All the spectroscopic studies and a substantial improvement in lubricity collectively supported a tenacious and associative interaction between PGM and cationized BLGs, but not between PGM and non-modified BLG. This study demonstrates a unique and successful approach to intensify the interaction between BLG and mucins, which is meaningful for a broad range of disciplines, including food science, macromolecular interactions, and biolubrication etc.


Asunto(s)
Cationes , Mucinas Gástricas , Lactoglobulinas , Animales , Porcinos , Mucinas Gástricas/química , Mucinas Gástricas/metabolismo , Cationes/química , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Dicroismo Circular , Etilenodiaminas/química , Electricidad Estática , Adsorción
6.
Anal Methods ; 16(19): 3039-3046, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38682261

RESUMEN

Beta-lactoglobulin (ß-Lg), a prominent milk protein, is a major contributor to milk allergies. The quantitative assessment of ß-Lg is a valuable method for assessing the allergenic potential of dairy products. In this study, a specific aptamer, ß-Lg-01, with an affinity constant (KD) of 28.6 nM for ß-Lg was screened through seven rounds of magnetic bead SELEX (MB-SELEX). A novel bio-layer interferometry (BLI)-based aptasensor was developed, which had a limit of detection (LOD) of 0.3 ng mL-1, a linear range of 1.5 ng mL-1-15 µg mL-1, and a recovery rate of 102-116% among the milk samples. This aptasensor provides a potential tool for the detection and risk assessment of ß-Lg within 10 min.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Lactoglobulinas , Leche , Técnica SELEX de Producción de Aptámeros , Lactoglobulinas/análisis , Lactoglobulinas/química , Leche/química , Técnicas Biosensibles/métodos , Animales , Aptámeros de Nucleótidos/química , Técnica SELEX de Producción de Aptámeros/métodos , Límite de Detección , Interferometría/métodos
7.
Int J Biol Macromol ; 268(Pt 1): 131773, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38657930

RESUMEN

The antigenicity of ß-lactoglobulin (ß-LG) can be influenced by pH values and reduced by epigallocatechin-3-gallate (EGCG). However, a detailed mechanism concerning EGCG decreasing the antigenicity of ß-LG at different pH levels lacks clarity. Here, we explore the inhibition mechanism of EGCG on the antigenicity of ß-LG at pH 6.2, 7.4 and 8.2 using enzyme-linked immunosorbent assay, multi-spectroscopy, mass spectrometry and molecular simulations. The results of Fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) elucidate that the noncovalent binding of EGCG with ß-LG induces variations in the secondary structure and conformations of ß-LG. Moreover, EGCG inhibits the antigenicity of ß-LG the most at pH 7.4 (98.30 %), followed by pH 6.2 (73.18 %) and pH 8.2 (36.24 %). The inhibitory difference is attributed to the disparity in the number of epitopes involved in the interacting regions of EGCG and ß-LG. Our findings suggest that manipulating pH conditions may enhance the effectiveness of antigenic inhibitors, with the potential for further application in the food industry.


Asunto(s)
Catequina , Lactoglobulinas , Lactoglobulinas/química , Lactoglobulinas/inmunología , Catequina/análogos & derivados , Catequina/química , Catequina/farmacología , Concentración de Iones de Hidrógeno , Simulación de Dinámica Molecular , Estructura Secundaria de Proteína , Dicroismo Circular , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Simulación del Acoplamiento Molecular , Antígenos/inmunología , Antígenos/química
8.
J Am Chem Soc ; 146(18): 12766-12777, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38656109

RESUMEN

Per- and polyfluoroalkyl substances (PFAS) pose significant health risks due to their widespread presence in various environmental and biological matrices. However, the molecular-level mechanisms underlying the interactions between PFAS and biological constituents, including proteins, carbohydrates, lipids, and DNA, remain poorly understood. Here, we investigate the interactions between a legacy PFAS, viz. perfluorooctanoic acid (PFOA), and the milk protein ß-lactoglobulin (BLG) obtained using a combination of experimental and computational techniques. Circular dichroism studies reveal that PFOA perturbs the secondary structure of BLG, by driving a dose-dependent loss of α-helicity and alterations in its ß-sheet content. Furthermore, exposure of the protein to PFOA attenuates the on-rate constant for the binding of the hydrophobic probe 8-anilino-1-naphthalene sulfonic acid (ANS), suggesting potential functional impairment of BLG by PFOA. Steered molecular dynamics and umbrella sampling calculations reveal that PFOA binding leads to the formation of an energetically favorable novel binding pocket within the protein, when residues 129-142 are steered to unfold from their initial α-helical structure, wherein a host of intermolecular interactions between PFOA and BLG's residues serve to insert the PFOA into the region between the unfolded helix and beta-sheets. Together, the data provide a novel understanding of the atomic and molecular mechanism(s) by which PFAS modulates structure and function in a globular protein, leading to a beginning of our understanding of altered biological outcomes.


Asunto(s)
Caprilatos , Fluorocarburos , Lactoglobulinas , Fluorocarburos/química , Caprilatos/química , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Sitios de Unión , Unión Proteica , Simulación de Dinámica Molecular , Conformación Proteica en Hélice alfa , Modelos Moleculares , Dicroismo Circular
9.
J Agric Food Chem ; 72(18): 10579-10583, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38683941

RESUMEN

A 14C-based method was developed to study the rate and extent of covalent bond formation between ß-lactoglobulin and three model flavor compounds: a ketone (2-undecanone UDO), an aldehyde (decanal DAL), an isothiocyanate (2-phenylethyl isothiocyanate PEITC), and an unreactive "methods blank" (decane DEC). Aqueous protein solutions with one of the 14C-labeled model flavor compounds were placed in water baths at 25, 45, and 65 °C for 4 weeks measuring the amount of flavor: protein reaction at 1, 3, 7, 14, 21, and 28 days. UDO showed lowest reactivity (max of 0.9% of added compound reacted), DAL (max of 16.4% reacted), and PEITC (max of 71.8% reacted). All compounds showed a rapid initial reaction rate which slowed after ca. 7 days. It appears that only PEITC (at 65 °C) saturated all potential protein-reactive sites over the storage period.


Asunto(s)
Aromatizantes , Isotiocianatos , Cetonas , Lactoglobulinas , Lactoglobulinas/química , Aromatizantes/química , Isotiocianatos/química , Cetonas/química , Radioisótopos de Carbono/análisis , Radioisótopos de Carbono/química , Aldehídos/química , Cinética
10.
Int J Biol Macromol ; 267(Pt 1): 131304, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38569999

RESUMEN

The study aimed to fabricate ß-Lactoglobulin-catechin (ß-La-Ca) conjugates as a natural designed antioxidant emulsifier to improve the physicochemical stability of resveratrol emulsion delivery system. Fourier transform infrared (FT-IR) and fluorescence spectroscopy analysis confirmed the formation of conjugates using free radical grafting. The antioxidant ability of emulsion was evaluated by DPPH scavenging activities and ORAC experiments. The emulsion stabilized by ß-La-Ca conjugates exhibited strong antioxidant activity with ORAC value of 2541.39 ± 29.58 µmol TE/g, which was significantly higher than that by ß-Lactoglobulin alone with 387.96 ± 23.45 µmol TE/g or their mixture with 948.23 ± 32.77 µmol TE/g. During the whole simulated gastrointestinal digestion, emulsion stabilized by ß-La-Ca conjugates exhibited excellent oxidative stability that the lipid was mainly digested in the small intestine. This behavior attributed to the greater stability of resveratrol to chemical transformation leading to a higher overall bioavailability in vivo. These results suggested that the ß-La-Ca conjugates could be used to fabricate the emulsion-based delivery system to improve the oxidative stability and bioavailability of chemically labile hydrophobic bioactive compounds.


Asunto(s)
Antioxidantes , Disponibilidad Biológica , Catequina , Emulsiones , Lactoglobulinas , Resveratrol , Resveratrol/química , Resveratrol/farmacocinética , Resveratrol/farmacología , Lactoglobulinas/química , Emulsiones/química , Antioxidantes/química , Antioxidantes/farmacocinética , Antioxidantes/farmacología , Catequina/química , Catequina/farmacocinética , Espectroscopía Infrarroja por Transformada de Fourier , Oxidación-Reducción
11.
Molecules ; 29(5)2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38474468

RESUMEN

Piceatannol (PIC) and epigallocatechin gallate (EGCG) are polyphenolic compounds with applications in the treatment of various diseases such as cancer, but their stability is poor. ß-lactoglobulin (ß-LG) is a natural carrier that provides a protective effect to small molecule compounds and thus improves their stability. To elucidate the mechanism of action of EGCG, PIC, and palmitate (PLM) in binding to ß-LG individually and jointly, this study applied molecular docking and molecular dynamics simulations combined with in-depth analyses including noncovalent interaction (NCI) and binding free energy to investigate the binding characteristics between ß-LG and compounds of PIC, EGCG, and PLM. Simulations on the binary complexes of ß-LG + PIC, ß-LG + EGCG, and ß-LG + PLM and ternary complexes of (ß-LG + PLM) + PIC, (ß-LG + PLM) + EGCG, ß-LG + PIC) + EGCG, and (ß-LG + EGCG) + PIC were performed for comparison and characterizing the interactions between binding compounds. The results demonstrated that the co-bound PIC and EGCG showed non-beneficial effects on each other. However, the centrally located PLM was revealed to be able to adjust the binding conformation of PIC, which led to the increase in binding affinity with ß-LG, thus showing a synergistic effect on the co-bound PIC. The current study of ß-LG co-encapsulated PLM and PIC provides a theoretical basis and research suggestions for improving the stability of polyphenols.


Asunto(s)
Lactoglobulinas , Polifenoles , Lactoglobulinas/química , Simulación del Acoplamiento Molecular , Unión Proteica
12.
Langmuir ; 40(14): 7733-7746, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38538620

RESUMEN

The mechanism of ethanol-induced fibrillation of ß-lactoglobulin (ß-lg) in the acidic aqueous solution upon heating was investigated using various techniques, mainly thioflavin T fluorescence, atomic force microscopy, nonreducing electrophoresis, mass spectrometry, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy. The results showed that fibrillation occurred with a heating time increase, but high ethanol content slowed down the process. At a low ethanol volume fraction, peptides existed after heating for 2 h, with long and straight fibrils formed after 4-6 h, while at a high ethanol volume fraction, the proteins aggregated with very few peptides appeared at the early stage of heating, and short and curved fibrils formed after heating for 8 h. Ethanol weakened the hydrophobic interactions between proteins in the aqueous solution; therefore the latter could not completely balance the electrostatic repulsion, and thus suppressing the fibrillation process. It is believed that the fibrillation of ß-lg in the acidic solution upon heating is mainly dominated by the polypeptide model; however, ethanol inhibited the hydrolysis of proteins, and the self-assembly mechanism changed to the monomer model.


Asunto(s)
Lactoglobulinas , Agua , Solventes/química , Lactoglobulinas/química , Péptidos , Etanol , Espectroscopía Infrarroja por Transformada de Fourier , Microscopía de Fuerza Atómica , Dicroismo Circular
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 313: 124090, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38428163

RESUMEN

(-)-Epicatechin gallate (ECG) and piceatannol (PIC) are commonly polyphenols with excellent biological activities. ß-Lactoglobulin (BLG) is a food-grade globule protein and its morphologies are sensitive to pH. This study used experimental and computational methods to determine the interaction of single or combined ECG and PIC with BLG at different pHs. The static quenching process was determined through fluorescence and ultraviolet-visible spectroscopy. Compared with ECG, PIC could significantly bind to BLG with higher affinity. Their binding affinity for BLG with different morphologies followed the tendency of monomer > dimer > tetramer. The negative contribution of van der Waals forces, electrostatic interactions, and hydrogen bonds to ΔHo exceeded the positive contribution of hydrophobic interactions in the spontaneous and exothermic process. The reduced binding affinity in the ternary systems demonstrated the competitive binding between ECG and PIC on BLG, and the hinder effect of ECG or PIC was enhanced with increasing pH. Molecular docking studies revealed the same binding sites of ECG and PIC on various conformations of BLG and identical driven forces as thermodynamic results. Tryptophan and tyrosine were the main participators in the BLG + ECG and BLG + PIC systems, respectively. The conformational changes in the binary and ternary systems could be ascertained through synchronous fluorescence, circular dichroism, and dynamic light scattering. Furthermore, the effects of pH and BLG encapsulation on the antioxidant capacity and stability of ECG or PIC were also implemented. ECG or PIC was the most stable in the (BLG + PIC) + ECG system at pH 6.0. This study could clarify the interaction mechanism between ECG/PIC and BLG and elucidate the pH effect on their binding information. The results will provide basic support for their usage in food processing and applications.


Asunto(s)
Antioxidantes , Catequina/análogos & derivados , Lactoglobulinas , Estilbenos , Antioxidantes/farmacología , Simulación del Acoplamiento Molecular , Lactoglobulinas/química , Dicroismo Circular , Unión Proteica
14.
Int J Biol Macromol ; 262(Pt 2): 129844, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38316325

RESUMEN

Milk samples were collected from 3625 Chinese Holstein cows to assess the effects of κ-casein (κ-CN) and ß-lactoglobulin (ß-LG) genetic variants on its milk coagulation properties. The results show that Chinese Holstein cows have a higher frequency of the κ-CN AA and AB variants, and ß-LG of the AB and AA variants. Of these, κ-CN B variants, the ß-LG AA and BB variants were more frequent in milk showing good coagulation. The effects of the genetic variants on milk composition, milk proteome, and protein phosphorylation sites were studied. The results showed that higher concentrations of protein and dry matter were found in κ-CN BE variant. Moreover, large variations in milk proteome among different κ-CN and ß-LG variants were observed. Highly phosphorylated for κ-CN, especially Ser97, was observed in cows with the κ-CN BE variant, but no effect of ß-LG variants on phosphorylation site was found. Of the various factors examined, variation of κ-CN phosphorylation sites Ser97 may be the most important in affecting casein structure and milk coagulation ability. Some milk protein contents were found to be negative factors for milk coagulation. In summary, this study showed that κ-CN genetic variants contained different milk compositions and phosphorylation site Ser97 influenced milk coagulation.


Asunto(s)
Leche , Proteoma , Animales , Femenino , Bovinos , Proteoma/metabolismo , Fosforilación , Leche/química , Proteínas de la Leche/química , Caseínas/química , Lactoglobulinas/genética , Lactoglobulinas/metabolismo , Genotipo
15.
Food Chem ; 446: 138844, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38422642

RESUMEN

This study prepared a novel, portable and cost-effective microfluidic paper-based electrochemical analysis device (µ-PAD) using black phosphorus nanosheets@carboxylated multi-walled carbon nanotubes (BPNSs@MWCNTs-COOH) nanocomposites for ß-lactoglobulin (ß-LG) detection. At the appreciate ratio, the synthesized BPNSs@MWCNTs-COOH was demonstrated to not only serve as a high-quality substrate for the specific aptamer immobilization, but also improve the electron transfer capability of the sensing interface. The µ-PADs, utilizing BPNSs@MWCNTs-COOH and aptamer recognition, exhibited a wider detection range (10-1000 ng mL-1) and lower detection limit (LOD: 0.12 ng mL-1) for ß-LG, and demonstrated enhanced specificity, satisfactory anti-interference ability and stability. When applied to the ß-LG determination in dairy samples, the µ-PAD yielded ß-LG concentrations highly correlated with those obtained using the HPLC method (R2: 0.9982). These results emphasized the reliable performance of the developed µ-PADs in ß-LG allergen quantification, highlighting their potential as an efficient platform for the rapid screening of ß-LG allergens.


Asunto(s)
Lactoglobulinas , Nanotubos de Carbono , Límite de Detección , Lactoglobulinas/análisis , Microfluídica , Técnicas Electroquímicas/métodos , Productos Lácteos/análisis , Alérgenos , Oligonucleótidos
16.
Colloids Surf B Biointerfaces ; 236: 113796, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38368756

RESUMEN

Kidney disease is currently prevalent worldwide but only shows insidious symptoms in the early stages. The second near-infrared window (NIR-II) fluorescence imaging has become a widely used preclinical technology for evaluating renal dysfunction due to its high resolution and sensitivity. However, bright renal clearable NIR-II fluorescence nanoprobes with a simple synthesis process are still lacking. Herein, we develop a lactoglobulin (LG)@dye nanoprobe for NIR-II fluorescence imaging of kidney dysfunction in vivo based on a purification-free method. The nanoprobe was synthesized by simply mixing LG and IR820 in aqueous solutions at 70 °C for 2 h based on the covalent interaction between the meso-Cl in IR820 and LG. The synthesized LG@IR820 nanoprobe has bright and stable NIR-II fluorescence, ultra-small size (<5 nm), low toxicity, and renal-clearable ability. The high reaction efficiency and pure aqueous reaction media make the synthesis method purification-free. In a unilateral ureteral obstruction mouse model, incipient renal dysfunction assessment was achieved by LG@IR820 nanoprobe, which couldn't be diagnosed with conventional kidney function indicators. This study provides a bright and purification-free NIR-II LG@IR820 nanoprobe to visualize kidney dysfunction at the early stage.


Asunto(s)
Enfermedades Renales , Lactoglobulinas , Animales , Ratones , Riñón/diagnóstico por imagen , Enfermedades Renales/diagnóstico por imagen , Agua , Imagen Óptica/métodos , Colorantes Fluorescentes
17.
Int J Biol Macromol ; 263(Pt 1): 130300, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38395276

RESUMEN

This work employed the model protein ß-lactoglobulin (BLG) to investigate the contribution of microstructural changes to regulating the interaction patterns between protein and flavor compounds through employing computer simulation and multi-spectroscopic techniques. The formation of molten globule (MG) state-like protein during the conformational evolution of BLG, in response to ultrasonic (UC) and heat (HT) treatments, was revealed through multi-spectroscopic characterization. Differential MG structures were distinguished by variations in surface hydrophobicity and the microenvironment of tryptophan residues. Fluorescence quenching measurements indicated that the formation of MG enhanced the binding affinity of heptanal to protein. LC-MS/MS and NMR revealed the covalent bonding between heptanal and BLG formed by Michael addition and Schiff-base reactions, and MG-like BLG exhibited fewer chemical shift residues. Molecular docking and molecular dynamics simulation confirmed the synergistic involvement of hydrophobic interactions and hydrogen bonds in shaping BLG-heptanal complexes thus promoting the stability of BLG structures. These findings indicated that the production of BLG-heptanal complexes was driven synergistically by non-covalent and covalent bonds, and their interaction processes were influenced by processes-induced formation of MG potentially tuning the release and retention behaviors of flavor compounds.


Asunto(s)
Aldehídos , Lactoglobulinas , Espectrometría de Masas en Tándem , Simulación del Acoplamiento Molecular , Lactoglobulinas/química , Cromatografía Liquida , Simulación de Dinámica Molecular
18.
Int J Biol Macromol ; 254(Pt 1): 127751, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38287593

RESUMEN

In order to meet the market demand and avoid the increase of operation amount and cleaning cost in the process of ultrafiltration, it is particularly important to find more practical and efficient methods to control and improve membrane fouling. In this study, the ions in the ultrafiltration process were regulated to affect membrane surface proteins composition (lactoferrin, α-lactalbumin, ß-lactoglobulin A and ß-lactoglobulin B) and delay membrane fouling. It was found that Na+ (21 mmol/L), Zn2+ (0.25 mmol/L) and K+ (44 mmol/L) was added at 4 min, 8 min and 12 min, respectively during ultrafiltration process. The continuous regulation slowed down the decline rate of membrane flux and reduced the content of α-lactalbumin, ß-lactoglobulin A and ß-lactoglobulin B on the membrane surface analyzed by HPLC. This could reduce the irreversible membrane fouling of proteins cake resistance. Furthermore, the ions concentration was also investigated after filtration. The concentration of K+ was increased significantly and other ions concentration was not significantly changed after continuous regulation such Na+, Mg2+, Zn2+ and Ca2+ compared to control. Therefore, dynamic ionic regulation of whey protein ultrafiltration process is a simple and effective method, which provides technical theoretical basis for optimizing and improving membrane technology.


Asunto(s)
Ultrafiltración , Purificación del Agua , Ultrafiltración/métodos , Proteína de Suero de Leche , Lactalbúmina , Cromatografía Líquida de Alta Presión , Lactoglobulinas , Proteínas de la Membrana , Factores de Transcripción , Iones , Membranas Artificiales , Purificación del Agua/métodos
19.
Food Res Int ; 177: 113855, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38225130

RESUMEN

Interaction of bovine ß-lactoglobulin (BLG) with several flavor compounds (FC) (2-methylpyrazine, vanillin, 2-acetylpyridine, 2- and 3-acetylthiophene, methyl isoamyl ketone, heptanone, octanone, and nonanone) was studied by high-sensitivity differential scanning calorimetry. The denaturation temperature, enthalpy, and heat capacity increment were determined at different FC concentrations. It was found that the denaturation temperature and heat capacity increment do not depend on the FC concentration, while the denaturation enthalpy decreases linearly with the FC concentration. These thermodynamic effects disclose the preferential FC binding to the unfolded form of BLG. By the obtained calorimetric data, the free energies of FC binding vs. the FC concentrations were calculated. These dependences were shown to be linear. Their slope relates closely to the overall FC affinity for the unfolded BLG in terms of the Langmuir binding model. The overall BLG affinity for FC varies from 20 M-1 (2-methylpyrazine) up to 360 M-1(nonanone). The maximal stoichiometry of the BLG-FC complexes was roughly estimated as a ratio of the length of the unfolded BLG to the molecular length of FC. Using these estimates, the apparent BLG-FC binding constants were determined. They are in the range of 0.3-8.0 M-1 and correlated strictly with the FC lipophilicity descriptor (logP).


Asunto(s)
Calor , Lactoglobulinas , Animales , Bovinos , Lactoglobulinas/química , Calorimetría , Termodinámica , Entropía , Cetonas
20.
Food Chem ; 442: 138414, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38237299

RESUMEN

Based on the findings of our previous studies, a comprehensive comparative investigation of the quality and formation mechanism of gels obtained from protein self-assemblies induced by different methods is necessary. Self-assembled heat-induced gels had higher gel mechanical strength, and hydrophobic interactions played a greater role. Whether or not heat treatment was used to induce gel formation may play a more important role than the effect of divalent cations on gel formation. Hydrogen bonds played an important role in all gels formed using different gelation methods. Furthermore, Self-assembled cold-induced gels were considered to can load bioactive substances with different hydrophilicity properties due to the high water-holding capacity and the smooth, dense microstructure. Therefore, ß-lactoglobulin fibrous and worm-like self-assembled cold-induced gels as a delivery material for hydrophilic bioactive substances (epigallocatechin gallate, vitamin B2) and amphiphilic bioactive substance (naringenin), with good encapsulation efficiency (91.92 %, 97.08 %, 96.72 %, 96.52 %, 98.94 %, 97.41 %, respectively) and slow-release performance.


Asunto(s)
Lactoglobulinas , Agua , Lactoglobulinas/química , Agua/química , Geles/química , Calor
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