scholarly journals Associations of a Polymorphic AP-2 Binding Site in the 5′-Flanking Region of the Bovine β-Lactoglobulin Gene with Milk Proteins

2003 ◽  
Vol 86 (6) ◽  
pp. 2213-2218 ◽  
Author(s):  
A.W. Kuss ◽  
J. Gogol ◽  
H. Geldermann
Keyword(s):  
Binding Site ◽  
Milk Proteins ◽  
Flanking Region ◽  
Β Lactoglobulin

Occurrence of milk proteins in the urine of cows during an extended milking interval

1967 ◽  
Vol 34 (1) ◽  
pp. 27-30 ◽  
Author(s):  
R. L. J. Lyster ◽  
J. V. Wheelock
Keyword(s):  
Molecular Weight ◽  
Milk Proteins ◽  
Immunological Methods ◽  
Factors Affecting ◽  
Β Lactoglobulin

SummaryImmunological methods have been used to test samples of urine from 5 cows for the presence of milk proteins. None could be detected when the cows were milked twice daily at the usual intervals, but during an extended milking interval α-lactalbumin was found in the urine of all 5 cows and β-lactoglobulin in the urine of 2 cows. The urine of one cow during and after a milking interval of 39 h contained 1·63 g α-lactalbumin, 1·12 g β-lactoglobulin and a small amount of casein. One of the factors affecting the transfer of these milk constituents from the udder to the urine appears to be their molecular weight.

Crystal structure of a secondary vitamin D3 binding site of milk β-lactoglobulin

2007 ◽  
Vol 71 (3) ◽  
pp. 1197-1210 ◽  
Author(s):  
Ming-Chi Yang ◽  
Hong-Hsiang Guan ◽  
Ming-Yih Liu ◽  
Yih-Hung Lin ◽  
Jinn-Moon Yang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Binding Site ◽  
Vitamin D3 ◽  
Β Lactoglobulin

scholarly journals Regulatory effect of heat shock transcription factor-1 gene on heat shock proteins and its transcriptional regulation analysis in small abalone Haliotis diversicolor

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Xin Zhang ◽  
Yuting Li ◽  
Yulong Sun ◽  
Mingxing Guo ◽  
Jianjun Feng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Heat Shock ◽  
Binding Site ◽  
Promoter Activity ◽  
Luciferase Activity ◽  
Haliotis Diversicolor ◽  
Shock Response ◽  
Flanking Region ◽  
Small Abalone ◽  
Shock Proteins

Abstract Background The effects of diverse stresses ultimately alter the structures and functions of proteins. As molecular chaperones, heat shock proteins (HSPs) are a group of highly conserved proteins that help in the refolding of misfolded proteins and the elimination of irreversibly damaged proteins. They are mediated by a family of transcription factors called heat shock factors (HSFs). The small abalone Haliotis diversicolor is a species naturally distributed along the southern coast of China. In this study, the expression of HdHSF1 was inhibited by RNAi in hemocytes in order to further elucidate the regulatory roles of HdHSF1 on heat shock responsive genes in abalone. Meanwhile, to understand the transcriptional regulation of the HdHSF1 gene, the 5′-upstream regulatory region of HdHSF1 was characterized, and the relative promoter activity was examined by dual-luciferase reporter gene assay system in HEK293T cell lines. Results After the inhibition of the H. diversicolor HSF1 gene (HdHSF1) by dsRNA (double-stranded RNA), the expression of most heat shock related-genes was down-regulated (p < 0.05). It indicated the importance of HdHSF1 in the heat shock response of H. diversicolor. Meanwhile, 5′-flanking region sequence (2633 bp) of the HdHSF1 gene was cloned; it contained a putative core promoter region, TATA box, CAAT box, CpG island, and many transcription elements. In HEK293T cells, the 5′-flanking region sequence can drive expression of the enhanced green fluorescent protein (EGFP), proving its promoter function. Exposure of cells to the high-temperature (39 °C and 42 °C) resulted in the activation of HdHSF1 promoter activity, which may explain why the expression of the HdHSF1 gene participates in heat shock response. Luciferase activity of different recombinant plasmids, which contained different truncated promoter fragments of the HdHSF1 gene in HEK293T cells, revealed the possible active regions of the promoter. To further identify the binding site of the critical transcription factor in the region, an expression vector with the site-directed mutation was constructed. After being mutated on the GATA-1 binding site, we found that the luciferase activity was significantly increased, which suggested that the GATA-1 binding site has a certain weakening effect on the activity of the HdHSF1 promoter. Conclusions These findings suggest that GATA-1 may be one of the transcription factors of HdHSF1, and a possible signaling pathway mediated by HdHSF1 may exist in H. diversicolor to counteract the adverse effects of heat shock stress.

Attachment of Listeria innocua to Polystyrene: Effects of Ionic Strength and Conditioning Films from Culture Media and Milk Proteins

2014 ◽  
Vol 77 (3) ◽  
pp. 427-434 ◽  
Author(s):  
GILLES ROBITAILLE ◽  
SÉBASTIEN CHOINIÈRE ◽  
TIMOTHY ELLS ◽  
LOUISE DESCHÈNES ◽  
AKIER ASSANTA MAFU
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bacterial Adhesion ◽  
Bovine Serum ◽  
Biofilm Formation ◽  
Milk Protein ◽  
Milk Proteins ◽  
Listeria Innocua ◽  
Conditioning Films ◽  
Β Lactoglobulin

It is recognized that bacterial adhesion usually occurs on conditioning films made of organic macromolecules absorbed to abiotic surfaces. The objectives of this study were to determine the extent to which milk protein–coated polystyrene (PS) pegs interfere with biofilm formation and the synergistic effect of this conditioning and hypertonic growth media on the bacterial adhesion and biofilm formation of Listeria innocua, used as a nonpathogenic surrogate for Listeria monocytogenes. PS pegs were uncoated (bare PS) or individually coated with whey proteins isolate (WPI), β-lactoglobulin, bovine serum albumin, or tryptic soy broth (TSB) and were incubated in bacterial suspensions in modified Welshimer's broth. After 4 h, the number of adherent cells was dependent on the coating, as follows: TSB (107 CFU/ml) &gt; bare PS &gt; β-lactoglobulin &gt; bovine serum albumin ≈ WPI (104 CFU/ml). The sessile cell counts increased up to 24 h, reaching &gt;107 CFU per peg for all surfaces (P &gt; 0.1), except for WPI-coated PS; this indicates that the inhibitory effects of milk protein conditioning films are transient, slowing down the adhesion process. The 4-h bacterial adhesion on milk protein–coated PS in modified Welshimer's broth supplemented with salt (0 to 10% [wt/vol]) did not vary (P &gt; 0.1), indicating that conditioning with milk proteins was the major determinant for inhibition of bacterial adhesion and that the synergetic effect of salt and milk proteins on adhesion was minimal. Moreover, the presence of 5 to 10% salt significantly inhibited 24-h biofilm formation on the TSB-coated and bare PS, with a decrease of &gt;3 log at 10% (wt/vol) NaCl and almost completely depleted viable sessile bacteria on the milk protein–coated PS.

scholarly journals Development and Validation of a Method for the Quantification of Milk Proteins in Food Products Based on Liquid Chromatography with Mass Spectrometric Detection

2011 ◽  
Vol 94 (4) ◽  
pp. 1043-1059 ◽  
Author(s):  
Petra Lutter ◽  
Véronique Parisod ◽  
Hans Weymuth
Keyword(s):  
Milk Powder ◽  
Skim Milk ◽  
Internal Standard ◽  
Milk Proteins ◽  
Skim Milk Powder ◽  
Selected Reaction Monitoring ◽  
Validation Data ◽  
Development And Validation ◽  
Protein Rich ◽  
Β Lactoglobulin

Abstract The protection of allergic consumers is crucial to the food industry. Therefore, accurate methods for the detection of food allergens are required. Targeted detection of selected molecules by MS combines high selectivity with accurate quantifcation. A confrmatory method based on LC/selected reaction monitoring (SRM)-MS/MS was established and validated for the quantifcation of milk traces in food. Tryptic peptides of the major milk proteins β-lactoglobulin, β-casein, αS2-casein, and κ-casein were selected as quantitative markers. Precise quantifcation was achieved using internal standard peptides containing isotopically labeled amino acids. For each peptide, qualifer and quantifer fragments were selected according to Commission Decision 2002/657/EC. A simple sample preparation method was established without immunoaffnity or SPE enrichment steps for food matrixes containing different amounts of protein, such as baby food, breakfast cereals, infant formula, and cereals. Intermediate reproducibility, repeatability, accuracy, and measurement uncertainty were determined for each matrix. LOD values of 0.2–0.5 mg/kg, e.g., for β-lactoglobulin, were comparable to those obtained with ELISA kits. An LOQ of approximately 5 mg/kg, expressed as mass fraction skim milk powder, was validated in protein-rich infant cereals. The obtained validation data show that the described LC/SRM-MS/MS approach can serve as a confrmatory method for the determination of milk traces in selected food matrixes.

Comparison of heat and pressure treatments of skim milk, fortified with whey protein concentrate, for set yogurt preparation: effects on milk proteins and gel structure

2000 ◽  
Vol 67 (3) ◽  
pp. 329-348 ◽  
Author(s):  
ERIC C. NEEDS ◽  
MARTA CAPELLAS ◽  
A. PATRICIA BLAND ◽  
PRETIMA MANOJ ◽  
DOUGLAS MACDOUGAL ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Whey Protein ◽  
Skim Milk ◽  
Milk Proteins ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Casein Micelles ◽  
Micelle Structure ◽  
Dynamic Structures ◽  
Β Lactoglobulin

Heat (85 °C for 20 min) and pressure (600 MPa for 15 min) treatments were applied to skim milk fortified by addition of whey protein concentrate. Both treatments caused > 90% denaturation of β-lactoglobulin. During heat treatment this denaturation took place in the presence of intact casein micelles; during pressure treatment it occurred while the micelles were in a highly dissociated state. As a result micelle structure and the distribution of β-lactoglobulin were different in the two milks. Electron microscopy and immunolabelling techniques were used to examine the milks after processing and during their transition to yogurt gels. The disruption of micelles by high pressure caused a significant change in the appearance of the milk which was quantified by measurement of the colour values L*, a* and b*. Heat treatment also affected these characteristics. Casein micelles are dynamic structures, influenced by changes to their environment. This was clearly demonstrated by the transition from the clusters of small irregularly shaped micelle fragments present in cold pressure-treated milk to round, separate and compact micelles formed on warming the milk to 43 °C. The effect of this transition was observed as significant changes in the colour indicators. During yogurt gel formation, further changes in micelle structure, occurring in both pressure and heat-treated samples, resulted in a convergence of colour values. However, the microstructure of the gels and their rheological properties were very different. Pressure-treated milk yogurt had a much higher storage modulus but yielded more readily to large deformation than the heated milk yogurt. These changes in micelle structure during processing and yogurt preparation are discussed in terms of a recently published micelle model.

scholarly journals A Novel method for Thermodynamic Study on the Binding of Milk Carrier protein of BLG-A with Cr+3

2009 ◽  
Vol 11 (4) ◽  
pp. 24-29
Author(s):  
G. Behbehania ◽  
A. Divsalar ◽  
A. Saboury
Keyword(s):  
Binding Site ◽  
Equilibrium Constants ◽  
Thermodynamic Study ◽  
Titration Calorimetry ◽  
Carrier Protein ◽  
Novel Method ◽  
The Stability ◽  
New Equation ◽  
Β Lactoglobulin ◽  
Association Equilibrium

A Novel method for Thermodynamic Study on the Binding of Milk Carrier protein of BLG-A with Cr+3 Thermodynamics of the interaction between Cr3+ with β-lactoglobulin type A (BLG-A) was investigated at pH 7.0 and 37°C by isothermal titration calorimetry. A new method to follow the effect of Cr3+ on the stability of BLG-A was introduced. The new solvation model was used to reproduce the enthalpies of BLG-A+ Cr3+ interactions over the whole range of Cr3+ concentrations. The solvation parameters recovered from the new equation are attributed to the structural change of BLG-A and its biological activity. The results obtained indicate that there is a set of two identical binding sites for Cr3+ ions with positive cooperativity. The association equilibrium constants are 14.39 and 0.49 mM-1 for the first and second binding site, respectively. The enthalpy of binding for one mole of Cr+3 ion to one mole of the binding site on BLG-A (ΔH=104.60 kJ mol-1) is obtained.

Allergy

PEDIATRICS ◽  
1991 ◽  
Vol 87 (6) ◽  
pp. 985-992
Keyword(s):  
Solid Phase ◽  
Milk Proteins ◽  
Subsequent Development ◽  
Specific Ige ◽  
Cow’S Milk Allergy ◽  
Cow’S Milk ◽  
Milk Allergy ◽  
Cow's Milk ◽  
Cow's Milk Allergy ◽  
Β Lactoglobulin

Pathophysiology MATERNAL IMMUNE STATUS AGAINST β-LACTOGLOBULIN AND COW'S MILK ALLERGY IN THE INFANT Casmir GJA, Duchateau J, Cuvelier P, Vis HL. Ann Allergy. 1989;63:517-519 Purpose of the Study The reported frequency of cow's milk allergy in children varies between 0.3% and 7.5% (population with earlier weaning has higher incidence). A thorough family history of atopy and cord IgE level at birth have been used to predict infants "at risk." Previous studies have shown that high cord IgE level (exceeding 1 IU/mL) was predictive of subsequent development of atopic disease. The purpose of this study was to follow-up the predictive relationship of maternal IgG-anti-BLG (IgG against β-lactoglobulin which is a major cow's milk antigen) and allergic manifestations in the infant. Study Population: Subject Section Mothers. All women were selected from the obstetric department of St Pierre Hospital in Brussels, Belgium. Infants. 69 infants were chosen who were born to these mothers by vaginal delivery and were fed cow's milk. Methods Clinical Evaluation. Every month during the first 6 months of life, infants were examined clinically for allergic symptoms. Gastrointestinal signs (diarrhea, vomiting, colic), atopic dermatitis, and respiratory problems (asthma, chronic cough, rhinitis) were recorded. Symptomatic children were treated with Alfare (Nestle) containing hydrolysates of cow's milk proteins with minimal allergenicity. Biologic Investigations. IgG-anti-BLG levels in mothers' sera were measured using solid-phase radioimmunoassay method. These levels were expressed in arbitrary units per milliliter. All children were screened for total IgE levels at 5 days of age. Specific IgE anti-cow's milk radioallergosorbent tests (RASTs) were performed in all patients at 1 month of age.

Sign in / Sign up

Export Citation Format

Share Document