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Polymers Oct 2021α-Lactalbumin is an essential protein with multiple roles in physiological and the nutritional functionalities, such as diabetic prevention, blood pressure...
α-Lactalbumin is an essential protein with multiple roles in physiological and the nutritional functionalities, such as diabetic prevention, blood pressure stabilization, and cancer cell inhibition. In the present work, polyethersulfone (PES)-based membranes were developed by incorporating Pluronic F127 and carbon nanotubes with single- and multi-walled dimensions (Sw-Cnts and Mw-Cnts) as additives. The resulting membranes were evaluated for use in the filtration of α-lactalbumin protein solution. Four series of membranes, including PES pristine membrane, were fabricated via the phase inversion process. The characteristics of the membrane samples were analyzed in terms of morphology, membrane surface hydrophilicity and roughness, and surface chemistry. The characterization results show that the incorporation of additive increased the surface wettability by reducing the surface water contact angle from 80.4° to 64.1° by adding F127 and Mw-Cnt additives. The highest pure water permeability of 135 L/(m·h·bar) was also exhibited by the PES/F127/Mw-Cnt membrane. The performance of the modified membranes was clearly better than the pristine PSF for α-lactalbumin solution filtration. The permeability of α-lactalbumin solution increased from 9.0 L/(m·h·bar) for the pristine PES membrane to 10.5, 11.0 and 11.5 L/(m·h·bar) for membranes loaded with Pluronic F127, Sw-Cnts, and Mw-Cnts, respectively. Those increments corresponded to 17, 22, and 28%. Such increments could be achieved without altering the α-lactalbumin rejections of 80%. Remarkably, the rejection for the membrane loaded with Sw-Cnts even increased to 89%.
PubMed: 34771192
DOI: 10.3390/polym13213632 -
Foods (Basel, Switzerland) Jan 2023Whey exhibits interesting nutritional properties, but its high β-Lactoglobulin (β-Lg) content could be a concern in infant food applications. In this study,...
Whey exhibits interesting nutritional properties, but its high β-Lactoglobulin (β-Lg) content could be a concern in infant food applications. In this study, high-pressure processing (HPP) was assessed as a β-Lg removal strategy to generate an enriched α-Lactalbumin (α-La) fraction from bovine native whey concentrate. Different HPP treatment parameters were considered: initial pH (physiological and acidified), sample temperature (7-35 °C), pressure (0-600 MPa) and processing time (0-490 s). The conditions providing the best α-La yield and α-La purification degree balance (46.16% and 80.21%, respectively) were 4 min (600 MPa, 23 °C), despite the significant decrease of the surface hydrophobicity and the total thiol content indexes in the α-La-enriched fraction. Under our working conditions, the general effects of HPP on α-La and β-Lg agreed with results reported in other studies of cow milk or whey. Notwithstanding, our results also indicated that the use of native whey concentrate could improve the β-Lg precipitation degree and the α-La purification degree, in comparison to raw milk or whey. Future studies should include further characterization of the α-La-enriched fraction and the implementation of membrane concentration and HPP treatment to valorize cheese whey.
PubMed: 36766009
DOI: 10.3390/foods12030480 -
Protein Science : a Publication of the... Sep 2021Amyloid fibrils are ordered aggregates that may be formed from disordered, partially unfolded, and fragments of proteins and peptides. There are several diseases, which...
Amyloid fibrils are ordered aggregates that may be formed from disordered, partially unfolded, and fragments of proteins and peptides. There are several diseases, which are due to the formation and deposition of insoluble β-sheet protein aggregates in various tissue, collectively known as amyloidosis. Here, we have used bovine α-lactalbumin as a model protein to understand the mechanism of amyloid fibril formation at pH 1.6 and 65°C under non-reducing conditions. Amyloid fibril formation is confirmed by Thioflavin T fluorescence and atomic force microscopy (AFM). Our finding demonstrates that hydrolysis of peptide bonds occurs under these conditions, which results in nicking and fragmentation. The nicking and fragmentation have been confirmed on non-reducing and reducing gel. We have identified the fragments by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The fragmentation may initiate nucleation as it coincides with AFM images. Conformational changes associated with monomer resulting in fibrillation are shown by circular dichroism and Raman spectroscopy. The current study highlights the importance of nicking and fragmentation in amyloid fibril formation, which may help understand the role of acidic pH and proteolysis under in vivo conditions in the initiation of amyloid fibril formation.
Topics: Amino Acid Sequence; Amyloid; Amyloidogenic Proteins; Animals; Benzothiazoles; Cattle; Hot Temperature; Hydrogen-Ion Concentration; Lactalbumin; Microscopy, Atomic Force; Models, Chemical; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand; Proteolysis; Spectrometry, Fluorescence
PubMed: 34107116
DOI: 10.1002/pro.4144 -
Nutrients Jun 2021Milk and dairy products, especially from cow's milk, play a major role in the daily human diet. It is therefore hardly surprising that the subject of milk is being... (Review)
Review
Milk and dairy products, especially from cow's milk, play a major role in the daily human diet. It is therefore hardly surprising that the subject of milk is being extensively researched and that many effects of individual milk components have been characterized as a result. With the wealth of results available today, the influence of milk on the development of various types of cancer and, in particular, its often protective effects have been shown both in vitro and in vivo and in the evaluation of large-scale cohort and case-control studies. Various caseins, diverse whey proteins such as α-lactalbumin (α-LA), bovine α-lactalbumin made lethal to tumor cells (BAMLET), β-lactoglobulin (β-LG), or bovine serum albumin (BSA), and numerous milk fat components, such as conjugated linoleic acid (CLA), milk fat globule membrane (MFGM), or butyrate, as well as calcium and other protein components such as lactoferrin (Lf), lactoferricin (Lfcin), and casomorphines, show antitumor or cytotoxic effects on cells from different tumor entities. With regard to a balanced and health-promoting diet, milk consumption plays a major role in a global context. This work provides an overview of what is known about the antitumoral properties of proteins derived from cow's milk and their modes of action.
Topics: Animals; Cattle; Chemoprevention; Milk; Milk Proteins; Neoplasms; Peptides
PubMed: 34201342
DOI: 10.3390/nu13061974 -
Metabolites May 2023Despite the beneficial effect of myo-inositol on metabolic, hormonal, and reproductive parameters of polycystic ovary syndrome (PCOS) patients, 28% to 38% could be...
Despite the beneficial effect of myo-inositol on metabolic, hormonal, and reproductive parameters of polycystic ovary syndrome (PCOS) patients, 28% to 38% could be resistant to this treatment. The combination with the milk protein α-lactalbumin can be a useful therapeutic approach to overcome inositol resistance and achieve ovulation in these women. This open-label prospective study aimed to compare the effects of supplementing myo-inositol plus α-lactalbumin vs myo-inositol alone on reproductive and metabolic abnormalities in PCOS. A total of 50 anovulatory women with a PCOS diagnosis were randomly assigned to receive myo-inositol alone or a combination of myo-inositol and α-lactalbumin for three months. Anthropometric measures, hormonal levels, and menstrual cycle duration were collected at baseline and after treatment. The therapy with myo-inositol plus α-lactalbumin improved both ovulation rate and menstrual cycle duration more than myo-inositol alone. The body weight was significantly reduced in women receiving myo-inositol plus α-lactalbumin, while patients in the myo-inositol group experienced no change. In addition, the improvement of hyperandrogenism was more prominent in patients treated with myo-inositol plus α-lactalbumin. The benefits of associating myo-inositol and α-lactalbumin clearly make this combination a true edge in the management of PCOS.
PubMed: 37367875
DOI: 10.3390/metabo13060717 -
Food Research International (Ottawa,... Mar 2023Chymotrypsin is one of the major proteases in intestinal protein digestion. Observations about the type of bonds that are hydrolysed (specificity and preference) were in...
Chymotrypsin is one of the major proteases in intestinal protein digestion. Observations about the type of bonds that are hydrolysed (specificity and preference) were in the past derived from the peptide composition after digestion or hydrolysis rates of synthetic peptides. In this study, the path of hydrolysis by bovine chymotrypsin, i.e formation and degradation of peptides, were described for α-lactalbumin, β-lactoglobulin and β-casein. The peptide compositions, determined with UPLC-PDA-MS at different time points were used to determine the digestion kinetics for individual cleavage sites. It was evaluated how statements on (secondary) specificity from literature were reflected in the release kinetics of peptides. β-Lactoglobulin reached the highest degree of hydrolysis (10.9 ± 0.1 %) and was hydrolysed fastest (28 ± 1 mM/s/mM), regardless of its globular (tertiary) structure. Chymotrypsin showed a preference towards aromatic amino acids, methionine and leucine, but was also tolerant to other amino acids. For the cleavage sites within this preference, ̴73% of the cleavage sites were hydrolysed with high or intermediate selectivity. For the missed cleavages within the preference, 45 % was explained by hindrance of proline, which affected hydrolysis only when in positions P3, P1' or P2'. No clear indication (based on primary structure) was found to explain the other missed cleavages. A few cleavage sites were hydrolysed extremely efficient in α-lactalbumin (F9, F31, W104) and β-casein (W143, L163, F190). This study gave unique and quantitative insight in peptide formation and degradation by chymotrypsin in the digestion of proteins. The approach used showed potential to explore the path of hydrolysis for other proteases with less defined specificity.
Topics: Cattle; Animals; Proteolysis; Chymotrypsin; Caseins; Lactalbumin; Endopeptidases; Peptide Hydrolases; Lactoglobulins; Transcription Factors
PubMed: 36869498
DOI: 10.1016/j.foodres.2023.112485 -
Food Chemistry: X Mar 2022Glycated protein is a kind of promising material that can improve the bioavailability of bioactive compounds and achieve sustained release under digestion. In this...
Glycated protein is a kind of promising material that can improve the bioavailability of bioactive compounds and achieve sustained release under digestion. In this study, the α-lactalbumin (ALA)-dextran conjugates synthesized by Maillard reaction were fabricated to load and protect quercetin. Quercetin-loaded micelles stabilized by the ALA-dextran conjugates 1:4 showed the smallest size (428.57 ± 5.64 nm) with highest encapsulation efficiency (94.38% ± 0.50%) of quercetin. Compared to ALA/dextran mixture complex, the conjugates-based micelles had better pH, ionic strength and photothermal stability. Furthermore, the micelles composed of the conjugates 1:2 and 1:4 showed the best controlled release effect during the simulated digestion, releasing 62.41% and 66.15% of quercetin from the total encapsulated contents, respectively, which was mainly related to the resistance of glycated ALA to the enzymes. The findings indicated that ALA-dextran conjugates could be effectively designed for the ideal delivery system of hydrophobic bioactive compounds in food industry.
PubMed: 35499028
DOI: 10.1016/j.fochx.2022.100257 -
Molecules (Basel, Switzerland) May 2021Milk and colostrum have high biological potential, and due to their natural origin and non-toxicity, they have many uses in cosmetics and dermatology. Research is... (Review)
Review
Milk and colostrum have high biological potential, and due to their natural origin and non-toxicity, they have many uses in cosmetics and dermatology. Research is ongoing on their potential application in other fields of medicine, but there are still few results; most of the published ones are included in this review. These natural products are especially rich in proteins, such as casein, β-lactoglobulin, α-lactalbumin, lactoferrin, immunoglobulins, lactoperoxidase, lysozyme, and growth factors, and possess various antibacterial, antifungal, antiviral, anticancer, antioxidant, immunomodulatory properties, etc. This review describes the physico-chemical properties of milk and colostrum proteins and the natural functions they perform in the body and compares their composition between animal species (cows, goats, and sheep). The milk- and colostrum-based products can be used in dietary supplementation and for performing immunomodulatory functions; they can enhance the effects of certain drugs and can have a lethal effect on pathogenic microorganisms. Milk products are widely used in the treatment of dermatological diseases for promoting the healing of chronic wounds, hastening tissue regeneration, and the treatment of acne vulgaris or plaque psoriasis. They are also increasingly regarded as active ingredients that can improve the condition of the skin by reducing the number of acne lesions and blackheads, regulating sebum secretion, ameliorating inflammatory changes as well as bestowing a range of moisturizing, protective, toning, smoothing, anti-irritation, whitening, soothing, and antiaging effects.
Topics: Animals; Anti-Bacterial Agents; Antifungal Agents; Antineoplastic Agents; Antioxidants; Antiviral Agents; Caseins; Colostrum; Cosmetics; Dermatology; Humans; Immunoglobulins; Immunologic Factors; Intercellular Signaling Peptides and Proteins; Lactalbumin; Lactoferrin; Lactoglobulins; Lactoperoxidase; Milk; Milk Proteins; Muramidase; Skin; Species Specificity
PubMed: 34071375
DOI: 10.3390/molecules26113253 -
Molecules (Basel, Switzerland) Aug 2022In this study, high pressure processing (HPP) and thermal treatment were comparatively evaluated by examining their impacts on the binding behavior and interaction...
In this study, high pressure processing (HPP) and thermal treatment were comparatively evaluated by examining their impacts on the binding behavior and interaction between α-lactalbumin (α-La) and pelargonium-3-glucoside (P3G) under pH values of 6.0, 7.4, and 8.0. The methods of circular dichroism spectroscopy, fluorescence quenching, dynamic light scattering, and molecular simulation were used to characterize the effects of processing-induced changes in protein structure, size distribution, binding site conformation, and residue charges on their binding characteristics between them. The results indicated that the thermal treatments significantly increased the quenching constants of the complex at pH 7.4/8.0 and 60/80 °C, as well as the accessible fraction of protein at pH 8.0/80 °C. Both HPP and thermal treatments increased the random coil content and showed limited effects on the α-helix and β-sheet contents of α-La and caused the aggregation of the complex to varying degrees. Molecular dynamic simulation and docking analyses revealed that the binding site of the complex did not change under different processing conditions, but the solvent-accessible surface area varied under different conditions.
Topics: Circular Dichroism; Glucosides; Hydrogen-Ion Concentration; Lactalbumin; Pelargonium; Spectrometry, Fluorescence
PubMed: 35956895
DOI: 10.3390/molecules27154944 -
European Review For Medical and... Apr 2021This open-label non-randomized clinical study aimed at evaluating the effects of myo-inositol plus alpha-lactalbumin in two groups of PCOS women, treated in Mexico and... (Clinical Trial)
Clinical Trial
OBJECTIVE
This open-label non-randomized clinical study aimed at evaluating the effects of myo-inositol plus alpha-lactalbumin in two groups of PCOS women, treated in Mexico and Italy. Alpha-lactalbumin was used being effective in increasing myo-inositol intestinal absorption. This effect is very useful in greatly reducing the therapeutic failure of myo-inositol in some patients (inositol resistant subjects).
PATIENTS AND METHODS
The study involved 34 normal weight or overweight patients (14 in Mexico and 20 in Italy), aged 18 to 40 years, with anovulation and infertility > 1 year and insulin resistance diagnosed by HOMA-Index. Patients were administered orally with 2 g myo-inositol, 50 mg alpha-lactalbumin, and 200 µg of folic acid twice a day for 6 months. Controls were the same patients at t0 (baseline). The primary outcome was HOMA-index decrease after 3 and 6 months of treatment. Other parameters monitored were BMI, progesterone, LH, FSH, total testosterone, free testosterone, androstenedione, total cholesterol, HDL, LDL, triglycerides.
RESULTS
Recovery was general, and its relevance was higher when the starting point was further away from the normal range. The most important results were obtained with insulin, HOMA-index, LH, and androstenedione. No significant adverse effects were detected in both groups of patients.
CONCLUSIONS
This clinical trial demonstrated for the first time that myo-inositol and alpha-lactalbumin improve important parameters in PCOS patients characterized by different metabolic profiles.
Topics: Adolescent; Adult; Female; Humans; Inositol; Italy; Lactalbumin; Mexico; Overweight; Polycystic Ovary Syndrome; Young Adult
PubMed: 33928619
DOI: 10.26355/eurrev_202104_25743