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The FEBS Journal Nov 2010Human α-lactalbumin made lethal to tumor cells (HAMLET) and equine lysozyme with oleic acid (ELOA) are complexes consisting of protein and fatty acid that exhibit... (Review)
Review
Human α-lactalbumin made lethal to tumor cells (HAMLET) and equine lysozyme with oleic acid (ELOA) are complexes consisting of protein and fatty acid that exhibit cytotoxic activities, drastically differing from the activity of their respective proteinaceous compounds. Since the discovery of HAMLET in the 1990s, a wealth of information has been accumulated, illuminating the structural, functional and therapeutic properties of protein complexes with oleic acid, which is summarized in this review. In vitro, both HAMLET and ELOA are produced by using ion-exchange columns preconditioned with oleic acid. However, the complex of human α-lactalbumin with oleic acid with the antitumor activity of HAMLET was found to be naturally present in the acidic fraction of human milk, where it was discovered by serendipity. Structural studies have shown that α-lactalbumin in HAMLET and lysozyme in ELOA are partially unfolded, 'molten-globule'-like, thereby rendering the complexes dynamic and in conformational exchange. HAMLET exists in the monomeric form, whereas ELOA mostly exists as oligomers and the fatty acid stoichiometry varies, with HAMLET holding an average of approximately five oleic acid molecules, whereas ELOA contains a considerably larger number (11- 48). Potent tumoricidal activity is found in both HAMLET and ELOA, and HAMLET has also shown strong potential as an antitumor drug in different in vivo animal models and clinical studies. The gain of new, beneficial function upon partial protein unfolding and fatty acid binding is a remarkable phenomenon, and may reflect a significant generic route of functional diversification of proteins via varying their conformational states and associated ligands.
Topics: Animals; Apoptosis; Autophagy; Chromatin; Cytoplasmic Vesicles; Fatty Acids; Humans; Lactalbumin; Models, Molecular; Muramidase; Neoplasms; Oleic Acids; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Protein Binding; Protein Conformation; Protein Folding
PubMed: 20977665
DOI: 10.1111/j.1742-4658.2010.07890.x -
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 -
Nutrition Reviews Dec 2021The significance of dairy in human health and nutrition is gaining significant momentum as consumers continue to desire wholesome, nutritious foods to fulfill their... (Review)
Review
The significance of dairy in human health and nutrition is gaining significant momentum as consumers continue to desire wholesome, nutritious foods to fulfill their health and wellness needs. Bovine milk not only consists of all the essential nutrients required for growth and development, it also provides a broad range of bioactive components that play an important role in managing human homeostasis and immune function. In recent years, milk bioactives, including α-lactalbumin, lactoferrin, glycomacropeptide, milk fat globule membrane, and milk oligosaccharides, have been intensively studied because of their unique bioactivity and functionality. Challenges for the application of these bioactive components in food and pharmaceutical formulations are associated with their isolation and purification on an industrial scale and also with their physical and chemical instability during processing, storage, and digestion. These challenges can be overcome by advanced separation techniques and sophisticated nano- or micro-encapsulation technologies. Current knowledge about the chemistry, separation, and encapsulation technology of major bioactives derived from bovine milk and their application in the food industry is reviewed here.
Topics: Animals; Humans; Lactalbumin; Milk; Milk Proteins; Milk, Human; Nutritional Status; Oligosaccharides; Technology
PubMed: 34879147
DOI: 10.1093/nutrit/nuab099 -
Nutrients Jul 2023The primary control of dysmetabolic patients is extremely challenging worldwide, with inadequate dietary habits and sporadic physical activity among the key risk factors...
The primary control of dysmetabolic patients is extremely challenging worldwide, with inadequate dietary habits and sporadic physical activity among the key risk factors for metabolic syndrome onset. Nowadays, there is no exclusive treatment for this condition, and considering that preventive measures usually fail, new therapeutic approaches need to be proposed and investigated. This present pilot study compared the effects of diet alone and in association with a combination of myo-inositol and d-chiro-inositol in their 40:1 ratio, α-lactalbumin, and on different metabolic parameters in obese dysmetabolic patients. To this purpose, 37 patients with BMI between 30 and 40 and fasting blood glucose between 100 and 125 mg/dL were divided into two groups: () the control group followed a hypocaloric Mediterranean diet, () while the study group was also supplemented with a daily dosage of two sachets, each one containing 1950 mg myo-inositol, 50 mg d-chiro-inositol, 50 mg α-lactalbumin, and 250 mg . After a 6-month treatment, all parameters improved in both groups. Nevertheless, the treated group experienced a greater improvement, especially concerning the variation from the baseline of HOMA index, triglycerides, BMI, body weight, and waist circumference. These findings support the supplementation with myo-inositol and d-chiro-inositol in the 40:1 ratio, α-lactalbumin, and as a therapeutical strategy to potentiate the beneficial effects induced via dietary programs in dysmetabolic patients.
Topics: Humans; Female; Lactalbumin; Gymnema sylvestre; Inositol; Pilot Projects; Diet; Obesity; Body Weight; Metabolome; Polycystic Ovary Syndrome
PubMed: 37513560
DOI: 10.3390/nu15143142 -
Molecules (Basel, Switzerland) Oct 2021In complex foods, bioactive secondary plant metabolites (SPM) can bind to food proteins. Especially when being covalently bound, such modifications can alter the...
In complex foods, bioactive secondary plant metabolites (SPM) can bind to food proteins. Especially when being covalently bound, such modifications can alter the structure and, thus, the functional and biological properties of the proteins. Additionally, the bioactivity of the SPM can be affected as well. Consequently, knowledge of the influence of chemical modifications on these properties is particularly important for food processing, food safety, and nutritional physiology. As a model, the molecular structure of conjugates between the bioactive metabolite benzyl isothiocyanate (BITC, a hydrolysis product of the glucosinolate glucotropaeolin) and the whey protein α-lactalbumin (α-LA) was investigated using circular dichroism spectroscopy, anilino-1-naphthalenesulfonic acid fluorescence, and dynamic light scattering. Free amino groups were determined before and after the BITC conjugation. Finally, mass spectrometric analysis of the BITC-α-LA protein hydrolysates was performed. As a result of the chemical modifications, a change in the secondary structure of α-LA and an increase in surface hydrophobicity and hydrodynamic radii were documented. BITC modification at the ε-amino group of certain lysine side chains inhibited tryptic hydrolysis. Furthermore, two BITC-modified amino acids were identified, located at two lysine side chains (K32 and K113) in the amino acid sequence of α-LA.
Topics: Amino Acid Sequence; Animals; Cattle; Circular Dichroism; Food Handling; Food Safety; Humans; Hydrodynamics; Hydrophobic and Hydrophilic Interactions; Isothiocyanates; Lactalbumin; Models, Molecular; Molecular Structure; Peptide Fragments; Protein Stability; Protein Structure, Secondary; Proteolysis; Tandem Mass Spectrometry
PubMed: 34684828
DOI: 10.3390/molecules26206247 -
Nutrients Nov 2021Frozen storage is necessary to preserve expressed human milk for critically ill and very preterm infants. Milk pasteurization is essential for donor milk given to this... (Review)
Review
Frozen storage is necessary to preserve expressed human milk for critically ill and very preterm infants. Milk pasteurization is essential for donor milk given to this special population. Due to these storage and processing conditions, subtle changes occur in milk nutrients. These changes may have clinical implications. Potentially, bioactive complexes of unknown significance could be found in human milk given to preterm infants. One such complex, a cytotoxic α-lactalbumin-oleic acid complex named "HAMLET," (Human Alpha-Lactalbumin Made Lethal to Tumor cells) is a folding variant of alpha-lactalbumin that is bound to oleic acid. This complex, isolated from human milk casein, has specific toxicity to both carcinogenic cell lines and immature non-transformed cells. Both HAMLET and free oleic acid trigger similar apoptotic mechanisms in tissue and stimulate inflammation via the NF-κB and MAPK p38 signaling pathways. This protein-lipid complex could potentially trigger various inflammatory pathways with unknown consequences, especially in immature intestinal tissues. The very preterm population is dependent on human milk as a medicinal and broadly bioactive nutriment. Therefore, HAMLET's possible presence and bioactive role in milk should be addressed in neonatal research. Through a pediatric lens, HAMLET's discovery, formation and bioactive benefits will be reviewed.
Topics: Caseins; Cytotoxins; Diet; Food Handling; Food Storage; Humans; Infant, Newborn; Infant, Premature; Lactalbumin; Milk, Human; Oleic Acids
PubMed: 34959888
DOI: 10.3390/nu13124336 -
Nutrients Jan 2020Human milk is rich in nutritional factors, such as alpha-lactalbumin (α-Lac), and important for neonatal development, but nutrient supplementation may be required for...
Human milk is rich in nutritional factors, such as alpha-lactalbumin (α-Lac), and important for neonatal development, but nutrient supplementation may be required for optimal growth. Using a pig model, we hypothesized that α-Lac-enriched whey protein concentrate (WPC) supplementation improves neonatal development. Cesarean-delivered preterm pigs were fed either dilute bovine milk (REF) or REF milk supplemented with WPC with normal (STANDARD-ALPHA) or high (HIGH-ALPHA) α-Lac. Clinical, gut, immune and cognitive endpoints (open field, T-maze) were assessed and tissues collected at Day 19. The growth of STANDARD-ALPHA and HIGH-ALPHA were higher than REF (31 vs. 19 g/kg/d). Most organ weights, gut, immunity and brain variables were similar between WPC groups. HIGH-ALPHA had a higher bone mineral content, colon microbial diversity and an abundance of specific bacteria and microbial metabolites, and tended to show a faster food transit time ( = 0.07). Relative to REF, WPC pigs showed higher relative organ weights, blood amino acids, blood neutrophil function, and microbial metabolites, but lower brush-border enzyme activities and plasma cortisol. Cognition outcomes did not differ among the groups. In conclusion, WPC supplementation of milk improved some growth, gut and immunity parameters in preterm pigs. However, increasing the α-Lac content beyond human milk levels had limited effects on the immature gut and developing brain.
Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Behavior, Animal; Brain; Cognition; Food, Formulated; Gastrointestinal Microbiome; Gestational Age; Immune System; Intestines; Lactalbumin; Nutritional Status; Nutritive Value; Sus scrofa; Whey Proteins
PubMed: 31963562
DOI: 10.3390/nu12010245 -
Biomolecules Mar 2021Protein aggregation and misfolding are some of the most challenging obstacles, customarily studied for their association with amyloid pathologies. The mechanism of...
Protein aggregation and misfolding are some of the most challenging obstacles, customarily studied for their association with amyloid pathologies. The mechanism of amyloid fibrillation development is a dynamic phenomenon involving various factors such as the intrinsic properties of protein and the physical and chemical environmental conditions. The purpose of this study was to see the thermal aggregation profile of alpha-lactalbumin (α-LA) and to delineate the effect of trehalose on its aggregation profile. α-LA was subjected to thermal aggregation at high concentrations. UV-Vis spectroscopy, a turbidity assay, intrinsic fluorescence, Rayleigh scattering and a thioflavin T (ThT) assay explained the steady outcomes that 1 M trehalose repressed α-LA aggregation in the most effective way followed by 0.75 M and 0.5 M and to a significantly lesser degree by 0.25 M. Multi spectroscopic obser Sania ations were further entrenched by microscopy. Transmission electron microscopy confirmed that in the presence of its higher concentration, trehalose hinders fibril development in α-LA. In vitro studies were further validated by in silico studies. Molecular docking analysis indicated that trehalose occupied the binding pocket cavity of α-LA and offered several significant interactions, including H-bonds with important residues. This study provides a platform for trehalose in the therapeutic management of protein aggregation-related diseases.
Topics: Animals; Benzothiazoles; Cattle; Lactalbumin; Molecular Docking Simulation; Nephelometry and Turbidimetry; Protein Aggregates; Protein Binding; Scattering, Radiation; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Temperature; Trehalose
PubMed: 33799517
DOI: 10.3390/biom11030414 -
Journal of Dairy Science Dec 2020Camel milk has unique physical, nutritional, and technological properties when compared with other milks, especially bovine. Because proteins confer many of the... (Comparative Study)
Comparative Study
Camel milk has unique physical, nutritional, and technological properties when compared with other milks, especially bovine. Because proteins confer many of the properties of milk and its products, this study aimed to determine the proteins of camel milk, their correlations, and relative distribution. Raw milk samples were collected from 103 dromedary camels in the morning and evening. Capillary electrophoresis results showed wide variation in the concentrations (g/L) of proteins between samples as follows: α-lactalbumin, 0.3 to 2.9; α-casein, 2.4 to 10.3; α-casein, 0.3 to 3.9; β-casein, 5.5 to 29.0; κ-casein, 0.1 to 2.4; unknown casein protein 1, 0.0 to 3.4; and unknown casein protein 2, 0.0 to 4.6. The range in percent composition of the 4 caseins were as follows: α, 12.7 to 35.3; α, 1.8 to 20.8; β, 42.3 to 77.4; and κ, 0.6 to 17.4. The relative proportion of α-, α-, β-, and κ-caseins in camel milk (26:4:67:3, wt/wt) differed from that of bovine milk (38:10:36:12, wt/wt). This difference might explain the dissimilarity between the 2 milks with respect to technical and nutritional properties.
Topics: Animals; Camelus; Caseins; Cattle; Electrophoresis, Capillary; Lactalbumin; Milk; Milk Proteins; Nutritive Value; Species Specificity
PubMed: 33069408
DOI: 10.3168/jds.2020-19122