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Journal of Agricultural and Food... Mar 2022Alpha-lactalbumin (α-LA; the most abundant whey protein in human milk) contributes to infant development, providing bioactive peptides and essential amino acids. Here,...
Alpha-lactalbumin (α-LA; the most abundant whey protein in human milk) contributes to infant development, providing bioactive peptides and essential amino acids. Here, () was selected as the production host. We found that the host X33 was suitable for expressing the target protein, yielding 5.2 mg·L α-LA. Thereafter, several secretory signal peptides were applied to obtain a higher titer of α-LA. The strain with α-factor secretory signal peptide secreted the highest extracellular titer. Additionally, promoters , , and were compared and applied. The strain with the promoter produced the highest extracellular titer. In addition, coexpressing human protein disulfide isomerase A3 (h) increased the titer by 27%. Human α-LA production by the strain X33-pPICZαA-hLALBA-hPDIA3 reached 56.3 mg·L in a 3 L bioreactor. This is the first report of successful secretory human α-LA expression in and lays foundations for the simulation of human milk for infant formulas and further development of bioengineered milk.
Topics: Child; Humans; Lactalbumin; Milk, Human; Pichia; Saccharomycetales
PubMed: 35148078
DOI: 10.1021/acs.jafc.1c07908 -
Spectrochimica Acta. Part A, Molecular... Nov 2023The combination of light and photoresponsive compounds provides a peculiar way of regulating biological systems. Azobenzene is a classical organic compound with...
The combination of light and photoresponsive compounds provides a peculiar way of regulating biological systems. Azobenzene is a classical organic compound with photoisomerization properties. Exploring the interactions between azobenzene and proteins can deepen the biochemical applications of the azobenzene compounds. In this paper, the interaction of 4-[(2,6-dimethylphenyl)diazenyl]-3,5-dimethylphenol with alpha-lactalbumin was investigated by UV-Vis absorption spectra, multiple fluorescence spectra, computer simulations, and circular dichroism spectra. Most critically, the interaction differences between proteins and the trans- and cis-isomer of ligands have been analyzed and compared. Results showed that both isomers of ligands were bound to alpha-lactalbumin to form ground state complexes and statically quenched the steady-state fluorescence of alpha-lactalbumin. The van der Waals forces and hydrogen bonding dominated the binding; the difference is that the binding of the cis-isomer to alpha-lactalbumin is more rapidly stabilized, and the binding strength is greater than the trans-isomer. These binding differences were modeled and analyzed by molecular docking and kinetic simulations, and we found that both isomers bind through the hydrophobic aromatic cluster 2 of alpha-lactalbumin. However, the bent structure of the cis-isomer is more closely aligned with the construction of the aromatic cluster and may have contributed to the above differences.
Topics: Lactalbumin; Molecular Docking Simulation; Ligands; Thermodynamics; Computer Simulation; Circular Dichroism
PubMed: 37327501
DOI: 10.1016/j.saa.2023.122965 -
Journal of Agricultural and Food... May 2021This study analyzed the effect of lipid peroxidation using 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) and acrolein on the and allergenicity of α-lactalbumin...
This study analyzed the effect of lipid peroxidation using 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) and acrolein on the and allergenicity of α-lactalbumin (α-La). The structure of oxidized α-La was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, fluorescence spectroscopy, and circular dichroism, whereas the changes in the allergenic properties were evaluated. Lipid peroxidation induced changes to the structural properties that might destroy and/or mask α-La epitopes. In comparison to native α-La, oxidation complexes caused a decrease in the immunoglobulin E (IgE) binding capacity, as observed via immunoblotting. Moreover, the capacity to release mediators and cytokines from KU812 cells was also greatly reduced. , oxidation with AAPH and acrolein caused a significant reduction in IgE, IgG, IgG1, mast cell protease 1, and plasma histamine, along with the reduction of mast surface c-Kit and FcεRI expression. Therefore, these results indicate that oxidation via AAPH and acrolein can potentially reduce the allergenicity of α-La, which can help with the better understanding of the changes in allergenicity of milk allergen by lipid peroxidation.
Topics: Allergens; Animals; Immunoglobulin E; Lactalbumin; Lipid Peroxidation; Milk
PubMed: 33974424
DOI: 10.1021/acs.jafc.1c00559 -
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 -
Food Chemistry Oct 2022This study aimed to isolate and evaluate the allergenicity of glycated α-lactalbumin (ALA) digestive products and identify its allergenic peptides. The digestive...
This study aimed to isolate and evaluate the allergenicity of glycated α-lactalbumin (ALA) digestive products and identify its allergenic peptides. The digestive products of native-, alone glycated- and ultrasound-assisted glycated ALA (ALA-D, ALA-gal-D, 100ALA-gal-D) were isolated into three fractions (F1, F2 and F3). High-resolution mass spectrometry showed that the digestion-resistant peptides of F2 and F3 mainly distributed in amino acid sequence (AA) 25-31, AA32-53, AA40-53, AA54-60, AA80-90, AA94-104. The allergenicity of the three fractions of glycated ALA was lower than that in ALA-D, indicating glycation of ALA could indeed reduce its allergenicity after digestion. Furthermore, most fractions isolated from high glycation-degree ALA had the lowest allergenicity. The IgG/IgE binding abilities of synthesized peptides indicated that AA94-104 firstly identified by us embodied the strongest allergenicity and might be the potential allergenic peptide. This will provide a theory for preparing hypoallergenic products based on the identified allergenic peptides.
Topics: Allergens; Glycosylation; Lactalbumin; Mass Spectrometry; Peptides
PubMed: 35567971
DOI: 10.1016/j.foodchem.2022.133185 -
Nutrition (Burbank, Los Angeles County,... Jun 2020The aim of this study was to demonstrate suitability and safety of an infant formula enriched with α-lactalbumin with a reduced protein content of 1.89 g protein/100... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
The aim of this study was to demonstrate suitability and safety of an infant formula enriched with α-lactalbumin with a reduced protein content of 1.89 g protein/100 kcal.
METHODS
This was a randomized, double-blind controlled trial with 80 healthy newborn infants who were assigned to receive either an isocaloric low- or high-protein content formula (1.89 versus 2.1 g/100 kcal). The low-protein content formula was enriched with α-lactalbumin. A breast-fed reference group of 40 infants was studied concurrently. Anthropometric measures were taken at inclusion, after 6 and 12 wk as well as after 6 and 12 mo of follow-up. Primary outcome was weight gain in g/d between study inclusion to 12 wk. Secondary outcomes included anthropometric measures expressed in Z-scores, mean formula consumption, and caloric intake as well as food tolerance.
RESULTS
Fifty-two infants in the formula group (low protein: 26, high protein: 26) and 32 in the breast-fed reference group completed the 3-mo intervention period. There was no difference in weight gain among feeding groups at the end of the intervention period. Mean weight gain in g/d was 32 in the low-protein, 31 in the high-protein, and 33 in the breast-fed reference group. No significant difference was found between study groups in Z-scores for weight, length, head circumference, weight-for-length, or body mass index nor for fat percentage at end of intervention and after follow-up.
CONCLUSION
α-lactalbumin-enriched formula with a protein content of 1.89 g protein/100 kcal is safe and supports adequate growth.
Topics: Breast Feeding; Diet, Protein-Restricted; Dietary Proteins; Female; Humans; Infant; Infant Formula; Infant Nutritional Physiological Phenomena; Infant, Newborn; Lactalbumin
PubMed: 32234653
DOI: 10.1016/j.nut.2020.110728 -
Current Protein & Peptide Science 2016This is a concluding part of the three-part article from a series of reviews on the abundance and roles of intrinsic disorder in milk proteins. In this paper, we... (Review)
Review
This is a concluding part of the three-part article from a series of reviews on the abundance and roles of intrinsic disorder in milk proteins. In this paper, we describe the peculiarities of metal binding to a multifunctional milk protein, α-lactalbumin, which has two domains, a large α-helical domain and a small β-sheet domain connected by a calcium binding loop. It is known that in addition to four disulfide bonds, the native fold of this protein is stabilized by binding of a calcium ion. In fact, although in various mammals, α-lactalbumins are rather poorly conserved possessing the overall sequence identity of ~16%, the positions of all eight cysteines and a calcium binding site (residues DKFLDDDITDDI in human protein) are strongly conserved. Curiously, this conserved calcium binding loop is located within a region with increased structural flexibility. Besides canonical calcium binding, α-lactalbumin is known to interact with other metals, such as zinc (for which it has a specific binding site), and, in its apo-form, it can bind other divalent and monovalent cations. The binding of Mg2+, Na+, and K+ to the Ca2+ site increases α-lactalbumin stability against action of heat and various denaturing agents, with the higher stabilization effects being imposed by the stronger bound metal ions.
Topics: Animals; Binding Sites; Calcium; Humans; Lactalbumin; Metals; Models, Molecular; Protein Binding; Protein Conformation; Thermodynamics
PubMed: 27238572
DOI: 10.2174/1389203717666160530151534 -
Nutrition Reviews Jul 2015Milk represents a unique resource for translational medicine: It contains a rich pool of biologically active molecules with demonstrated clinical benefits. The ongoing... (Review)
Review
Milk represents a unique resource for translational medicine: It contains a rich pool of biologically active molecules with demonstrated clinical benefits. The ongoing characterization of the mechanistic process through which milk components promote development and immunity has revealed numerous milk-derived compounds with potential applications as clinical therapies in infectious and inflammatory disease, cancer, and other conditions. Lactoferrin is an effective antimicrobial and antiviral agent in high-risk patient populations and a potentially potent adjuvant to chemotherapy in lung cancer. Enteric nutrition formulas supplemented with transforming growth factor β, a milk cytokine, have been shown to promote remission in pediatric Crohn's disease. A number of milk glycans, including human milk oligosaccharides, show promise in preclinical studies as antimicrobial and anti-inflammatory agents. While active preclinical investigations of human milk may soon result in large-scale production of human milk molecules, bovine milk components in many instances represent a practical source of bioactive milk compounds for use in clinical trials. This review summarizes current efforts to translate the compounds derived from human and bovine milk into effective clinical therapies. These efforts suggest a common pathway for the translation of milk-derived compounds into clinical applications.
Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Antineoplastic Agents; Caseins; Cattle; Cell Line, Tumor; Crohn Disease; Humans; Lactalbumin; Lactoferrin; Milk; Milk, Human; Oligosaccharides; Randomized Controlled Trials as Topic; Transforming Growth Factor beta
PubMed: 26011900
DOI: 10.1093/nutrit/nuv009 -
Food Chemistry Aug 2021Numerous human conditions can benefit from diets rich in proteins and bioactives, such as capsaicin (CAP), yet their effective delivery is a sensorial, scientific and...
Numerous human conditions can benefit from diets rich in proteins and bioactives, such as capsaicin (CAP), yet their effective delivery is a sensorial, scientific and technological challenge. This study hypothesized that CAP can form various complexes with native bovine alpha-lactalbumin (holo-ALA) and decalcified-ALA (apo-ALA). Calorimetric and spectroscopic techniques reveals ALA-CAP molecular complexation is spontaneous, exothermic and accompanied by various conformational changes. ITC shows the interaction stoichiometry (n) and binding constant (K) for holo-ALA to be 0.87 ± 0.03, 1.54 ± 0.23 × 10 M and for apo-ALA to be 0.64 ± 0.09, 9.41 ± 2.16 × 10 M. Molecular docking further elucidates that hydrogen bonds govern CAP binding to holo-ALA while hydrophobic interactions dominate binding to apo-ALA in a structural cleft. Finally, this work shows these interactions along with controlled aggregation can be utilized to form CAP-loaded colloids with encapsulation efficiency of 47.1 ± 1.0%. Thus, this study shows great promise in the prospective use of ALA as an edible delivery vehicle for CAP.
Topics: Animals; Capsaicin; Cattle; Chemical Phenomena; Humans; Hydrophobic and Hydrophilic Interactions; Lactalbumin; Molecular Docking Simulation; Protein Binding
PubMed: 33677213
DOI: 10.1016/j.foodchem.2021.129306 -
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