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Gazi I, Reiding KR, Groeneveld A, Bastiaans J, Huppertz T, Heck AJR. LacdiNAc to LacNAc: remodelling of bovine α-lactalbumin N-glycosylation during the transition from colostrum to mature milk. Glycobiology 2024; 34:cwae062. [PMID: 39115362 PMCID: PMC11319639 DOI: 10.1093/glycob/cwae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 08/05/2024] [Accepted: 08/07/2024] [Indexed: 08/15/2024] Open
Abstract
α -Lactalbumin, an abundant protein present in the milk of most mammals, is associated with biological, nutritional and technological functionality. Its sequence presents N-glycosylation motifs, the occupancy of which is species-specific, ranging from no to full occupancy. Here, we investigated the N-glycosylation of bovine α-lactalbumin in colostrum and milk sampled from four individual cows, each at 9 time points starting from the day of calving up to 28.0 d post-partum. Using a glycopeptide-centric mass spectrometry-based glycoproteomics approach, we identified N-glycosylation at both Asn residues found in the canonical Asn-Xxx-Ser/Thr motif, i.e. Asn45 and Asn74 of the secreted protein. We found similar glycan profiles in all four cows, with partial site occupancies, averaging at 35% and 4% for Asn45 and Asn74, respectively. No substantial changes in occupancy occurred over lactation at either site. Fucosylation, sialylation, primarily with N-acetylneuraminic acid (Neu5Ac), and a high ratio of N,N'-diacetyllactosamine (LacdiNAc)/N-acetyllactosamine (LacNAc) motifs were characteristic features of the identified N-glycans. While no substantial changes occurred in site occupancy at either site during lactation, the glycoproteoform (i.e. glycosylated form of the protein) profile revealed dynamic changes; the maturation of the α-lactalbumin glycoproteoform repertoire from colostrum to mature milk was marked by substantial increases in neutral glycans and the number of LacNAc motifs per glycan, at the expense of LacdiNAc motifs. While the implications of α-lactalbumin N-glycosylation on functionality are still unclear, we speculate that N-glycosylation at Asn74 results in a structurally and functionally different protein, due to competition with the formation of its two intra-molecular disulphide bridges.
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Affiliation(s)
- Inge Gazi
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht 3584 CH, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht 3584 CH, The Netherlands
| | - Karli R Reiding
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht 3584 CH, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht 3584 CH, The Netherlands
| | - André Groeneveld
- Research and Development, FrieslandCampina, Stationsplein 4, Amersfoort 3818 LE, The Netherlands
| | - Jan Bastiaans
- Research and Development, FrieslandCampina, Stationsplein 4, Amersfoort 3818 LE, The Netherlands
| | - Thom Huppertz
- Research and Development, FrieslandCampina, Stationsplein 4, Amersfoort 3818 LE, The Netherlands
- Department of Agrotechnology and Food Sciences, Wageningen University, Bornse Weilanden 9, Wageningen 6708 WG, The Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, Utrecht 3584 CH, The Netherlands
- Netherlands Proteomics Center, Padualaan 8, Utrecht 3584 CH, The Netherlands
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Stastna M, Šlais K. Preparative separation of immunoglobulins from bovine colostrum by continuous divergent-flow electrophoresis. J Sep Sci 2023; 46:e2200679. [PMID: 36271766 DOI: 10.1002/jssc.202200679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 01/11/2023]
Abstract
Immunoglobulins in bovine colostrum were separated and fractionated from other proteins using the method and instrumentation developed in our laboratory. The proposed separation was based on bidirectional isotachophoresis/moving boundary electrophoresis with electrofocusing of the analytes in a pH gradient from 3.9 to 10.1. The preparative instrumentation included the trapezoidal non-woven fabric that served as separation space with divergent continuous flow. The defatted and casein precipitate-free colostrum supernatant was loaded directly into the instrument without any additional colostrum pre-preparation. Immunoglobulin G was fractionated from other immune proteins such as bovine serum albumin, β-lactoglobulin, and α-lactalbumin, and was continuously collected in separated fractions over 3 h. The fractions were further processed, and isolated immunoglobulin G in the liquid fractions was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by re-focusing in gel isoelectric focusing. Separated immunoglobulin G was detected in seven fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a gradually decreased concentration in the fractions. Re-focusing of the proteins in the fractions by gel isoelectric focusing revealed multiple separated zones of immunoglobulin G with the isoelectric point values covering the range from 5.4 to 7.2. Each fraction contained distinct zones with gradually increased isoelectric point values and decreased concentrations from fraction to fraction.
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Affiliation(s)
- Miroslava Stastna
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Brno, Czech Republic
| | - Karel Šlais
- Institute of Analytical Chemistry of the Czech Academy of Sciences, Brno, Czech Republic
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3
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Separation methods for milk proteins on polyacrylamide gel electrophoresis: Critical analysis and options for better resolution. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2020.104920] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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4
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Identification of cow, buffalo, goat and ewe milk species in fermented dairy products using synchronous fluorescence spectroscopy. Food Chem 2019; 284:60-66. [PMID: 30744868 DOI: 10.1016/j.foodchem.2019.01.093] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 01/11/2019] [Accepted: 01/13/2019] [Indexed: 11/24/2022]
Abstract
In the dairy industry, substitution of high priced milk species with low priced ones is a common practice, and determination of milk species is critical. In this study, synchronous fluorescence spectroscopy (SFS) method was developed for identification of milk species in fermented dairy products (yoghurt and cheese). Three partial least square-discriminant analysis models were developed in order to identify pure-mixed samples, milk species and binary mixture type, and partial least square (PLS) model was utilized to quantify the mixing ratio in binary mixtures. PLS models used for yoghurt and cheese samples showed that detection limits of adulteration were below 3.3%. Apart from the buffalo-cow yoghurt and goat-cow cheese, precision of the measurements was found to be below 6.2. It can be said that SFS technique is applicable on yoghurt and cheese samples as it's a less destructive and a less costly method compared to DNA and protein based conventional methods.
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5
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Discrimination between cheeses made from cow’s, ewe’s and goat’s milk from unsaturated fatty acids and use of the canonical biplot method. J Food Compost Anal 2017. [DOI: 10.1016/j.jfca.2016.12.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Hou X, Sun M, He X, Chen L, Zhang P, He L. Simultaneous quantification of five proteins and seven additives in dairy products with a heart-cutting two-dimensional liquid chromatography method. J Sep Sci 2015; 38:3832-3838. [DOI: 10.1002/jssc.201500684] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/25/2015] [Accepted: 08/26/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Xiaofang Hou
- School of Pharmacy; Xi'an Jiaotong University; Xi'an China
| | - Meng Sun
- School of Pharmacy; Xi'an Jiaotong University; Xi'an China
| | - Xiaoshuang He
- School of Pharmacy; Xi'an Jiaotong University; Xi'an China
| | - Liang Chen
- School of Pharmacy; Xi'an Jiaotong University; Xi'an China
| | - Ping Zhang
- School of Pharmacy; Xi'an Jiaotong University; Xi'an China
| | - Langchong He
- School of Pharmacy; Xi'an Jiaotong University; Xi'an China
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7
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Pomastowski P, Sprynskyy M, Buszewski B. The study of zinc ions binding to casein. Colloids Surf B Biointerfaces 2014; 120:21-7. [DOI: 10.1016/j.colsurfb.2014.03.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 03/02/2014] [Accepted: 03/03/2014] [Indexed: 11/30/2022]
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8
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Song F, Zhou Y, Li YS, Meng XM, Meng XY, Liu JQ, Lu SY, Ren HL, Hu P, Liu ZS, Zhang YY, Zhang JH. A rapid immunomagnetic beads-based immunoassay for the detection of β-casein in bovine milk. Food Chem 2014; 158:445-8. [PMID: 24731368 DOI: 10.1016/j.foodchem.2014.02.150] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 09/22/2013] [Accepted: 02/26/2014] [Indexed: 11/17/2022]
Abstract
An immunomagnetic beads-based enzyme-linked immunosorbent assay (IMBs-ELISA) was developed for the detection of β-casein in bovine milk. Immunomagnetic beads (IMBs) were employed as the solid phase. The anti-β-casein monoclonal antibody (McAb) bound to IMBs was used as capture probe and an anti-β-casein polyclonal antibody (PcAb), labelled with horseradish peroxidase (HRP), was employed as detector probe. Three reaction and two washing steps were needed. Each reaction needed 10 min or less, which significantly shortened detection compared with classic sandwich ELISA. β-Casein in bovine milk was detected across a linear range (2-128 μg mL(-1)). Application results were in accordance with the Kjejdahl method, which suggests the IMBs-ELISA is rapid and reliable for the detection of β-casein in bovine milk.
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Affiliation(s)
- F Song
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - Y Zhou
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China.
| | - Y S Li
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - X M Meng
- Grain and Oil Food Processing Key Laboratory of Jilin Province, Jilin Business and Technology College, Changchun 130062, PR China
| | - X Y Meng
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - J Q Liu
- Production Quality Test Institute of Jilin Province, Changchun 130022, PR China
| | - S Y Lu
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - H L Ren
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - P Hu
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - Z S Liu
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - Y Y Zhang
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
| | - J H Zhang
- Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis/College of Veterinary Medicine, Jilin University, Changchun 130062, PR China
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9
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Prediction of the type of milk and degree of ripening in cheeses by means of artificial neural networks with data concerning fatty acids and near infrared spectroscopy. Talanta 2013; 116:50-5. [DOI: 10.1016/j.talanta.2013.04.043] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 04/12/2013] [Accepted: 04/21/2013] [Indexed: 11/23/2022]
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10
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Analysis of bovine milk caseins on organic monolithic columns: An integrated capillary liquid chromatography–high resolution mass spectrometry approach for the study of time-dependent casein degradation. J Chromatogr A 2013; 1313:259-69. [DOI: 10.1016/j.chroma.2013.08.083] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 08/21/2013] [Accepted: 08/21/2013] [Indexed: 11/18/2022]
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11
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Sanz Ceballos L, Sanz Sampelayo M, Gil Extremera F, Rodríguez Osorio M. Evaluation of the allergenicity of goat milk, cow milk, and their lactosera in a guinea pig model. J Dairy Sci 2009; 92:837-46. [DOI: 10.3168/jds.2008-1125] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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12
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Proteolysis in model Portuguese cheeses: Effects of rennet and starter culture. Food Chem 2008; 108:862-8. [DOI: 10.1016/j.foodchem.2007.11.050] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 10/08/2007] [Accepted: 11/21/2007] [Indexed: 11/21/2022]
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13
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Bonfatti V, Grigoletto L, Cecchinato A, Gallo L, Carnier P. Validation of a new reversed-phase high-performance liquid chromatography method for separation and quantification of bovine milk protein genetic variants. J Chromatogr A 2008; 1195:101-6. [PMID: 18495141 DOI: 10.1016/j.chroma.2008.04.075] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 04/28/2008] [Accepted: 04/29/2008] [Indexed: 10/22/2022]
Abstract
A new RP-HPLC method for the separation and quantification of the most common genetic variants of bovine milk proteins is described. A reversed-phase analytical column C8 (Zorbax 300SB-C8 RP, 3.5 microm, 300A, 150 x 4.6 I.D.) was used. All the most common casein (CN) and whey protein genetic variants, including beta-CN(I) were detected and separated simultaneously in less then 40 min, with the exception of alpha(S1)-CN(B) and CN(C) variants. Purified protein genetic variants were employed in calibration and showed different absorbances at 214 nm. The procedure was developed using 40 raw individual milk samples of cows belonging to four different breeds and certified skim milk powder BCR-063R. Method validation consisted in testing linearity, repeatability, reproducibility and accuracy. A linear relationship (R(2)>0.99) between the concentrations of proteins and peak areas was observed over the concentration range, with low detection limits. Repeatability and reproducibility were satisfactory for both retention times and peak areas. The RSD of peak areas ranged from 0.92 to 4.32% within analytical day and from 0.85 to 9.52% across analytical days. The recoveries, calculated using mixtures of samples previously quantified, ranged from 98.1 to 103.7%.
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Affiliation(s)
- Valentina Bonfatti
- Department of Animal Science, University of Padova, Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
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14
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Determination of the percentage of milk (cow's, ewe's and goat's) in cheeses with different ripening times using near infrared spectroscopy technology and a remote reflectance fibre-optic probe. Anal Chim Acta 2007; 604:191-6. [DOI: 10.1016/j.aca.2007.10.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 09/14/2007] [Accepted: 10/11/2007] [Indexed: 11/17/2022]
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15
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Santos LHLMLM, Ferreira IMPLVO. Quantification of α-lactalbumin in human milk: Method validation and application. Anal Biochem 2007; 362:293-5. [PMID: 17223064 DOI: 10.1016/j.ab.2006.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Accepted: 12/04/2006] [Indexed: 11/22/2022]
Affiliation(s)
- Lúcia H L M L M Santos
- REQUIMTE, Serviço de Bromatologia, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 4050-047 Porto, Portugal
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16
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Manso MA, Miguel M, López-Fandiño R. Application of capillary zone electrophoresis to the characterisation of the human milk protein profile and its evolution throughout lactation. J Chromatogr A 2007; 1146:110-7. [PMID: 17320885 DOI: 10.1016/j.chroma.2007.01.100] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 12/18/2006] [Accepted: 01/26/2007] [Indexed: 10/23/2022]
Abstract
This work describes the use of capillary zone electrophoresis for the characterisation of human milk proteins. The major proteins were identified following different strategies, such as the treatment with enzymes for selective protein modification. Using this method we studied the proteins in human milk from different donors throughout lactation. Qualitative and quantitative differences in the composition of the individual proteins were observed. The different beta-casein phosphoforms were separated and quantified. The average proportion of the 0P:1P:2P:3P:4P:5P was, approximately, 3:6:9:4:10:2. The evolution of the ratio of the different beta-casein phosphoforms during lactation is reported.
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Affiliation(s)
- M A Manso
- Instituto de Fermentaciones Industriales (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
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17
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Colak H, Aydin A, Nazli B, Ergun O. Detection of presence of cow’s milk in sheep’s cheeses by immunochromatography. Food Control 2006. [DOI: 10.1016/j.foodcont.2005.06.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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19
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Rehder-Silinski MA, McGown LB. Capillary electrochromatographic separation of bovine milk proteins using a G-quartet DNA stationary phase. J Chromatogr A 2003; 1008:233-45. [PMID: 12967187 DOI: 10.1016/s0021-9673(03)00973-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
DNA oligonucleotides that form G-quartet structures were used as stationary phase reagents for separation of bovine milk proteins, including alpha-casein, beta-casein, kappa-casein, alpha-lactalbumin and beta-lactoglobulin. Both artificial protein mixtures and a skim milk sample were analyzed. The separations were performed using open-tubular capillary electrochromatography, in which the oligonucleotides were covalently attached to the inner surface of a fused-silica capillary. Better resolution was achieved using the G-quartet-coated capillaries than was achieved using either a bare capillary or a capillary coated with an oligonucleotide that does not form a G-quartet structure. A 4-plane G-quartet-forming stationary phase was able to resolve three peaks for alpha-casein and to detect thermal denaturation of the proteins in the milk sample. The results suggest that G-quartet stationary phases could be used to separate very similar protein structures, such as those arising from genetic variations or post-translational modifications.
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20
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Veloso ACA, Teixeira N, Ferreira IMPLVO. Separation and quantification of the major casein fractions by reverse-phase high-performance liquid chromatography and urea-polyacrylamide gel electrophoresis. Detection of milk adulterations. J Chromatogr A 2002; 967:209-18. [PMID: 12685568 DOI: 10.1016/s0021-9673(02)00787-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The separation and quantification of bovine kappa-, alpha- and beta-caseins by HPLC-UV using an RP column which contained polystyrene-divinilbenzene copolymer based packing was optimized and validated. Gradient elution was carried out at a flow-rate of 1 ml/min and a temperature of 46 degrees C, using a mixture of two solvents. Solvent A was 0.1% trifluoroacetic acid in water and solvent B was acetonitrile-water-trifluoroacetic acid (95:5:0.1). The effluent was monitored by a UV detector at 280 nm. The determinations were performed in the linear range of 0.038-0.377 mg/ml for kappa-casein, 0.188-1.883 mg/ml for alpha-casein and 0.151-1.506 mg/ml for beta-casein. The detection limits were 0.006, 0.019 and 0.015 mg/ml for kappa-casein, alpha-casein and beta-casein, respectively. The validity of the method was verified. The recoveries ranged from 91 to 100% for bovine milk. The precision of the method was also evaluated, the RSD being less than 3.67%. The same HPLC procedure was used for the separation of caprine and ovine caseins. Different chromatographic profiles were obtained for bovine, ovine and caprine milks, although it was only possible to detect and quantify additions of 5% or more of bovine milk to caprine milk. With respect to detection of milk adulterations, electrophoresis using urea-polyacrylamide gel electrophoresis (PAGE) analysis was more sensitive. The evolution of casein proteolysis in cheeses made from bovine milk and cheeses made from ovine milk, during 30 days of ripening was followed by HPLC-UV and urea-PAGE methodologies. The results obtained by these techniques were similar.
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Affiliation(s)
- Ana C A Veloso
- CEQUP/Serviço de Bromatologia, Faculdade de Farmácia da Universidade do Porto, Rua Aníbal Cunha 164, 4050 Oporto, Portugal
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21
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Marvin LF, Parisod V, Fay LB, Guy PA. Characterization of lactosylated proteins of infant formula powders using two-dimensional gel electrophoresis and nanoelectrospray mass spectrometry. Electrophoresis 2002; 23:2505-12. [PMID: 12210209 DOI: 10.1002/1522-2683(200208)23:15<2505::aid-elps2505>3.0.co;2-m] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Infant formula powders were analyzed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) to assess the whey proteins quality, which may be altered by the heat treatment used during the processing conditions. Lactosylation was found to be the major chemical modification occurring in whey proteins. In parallel, a two-dimensional (2-D) gel electrophoresis was performed on the milk sample and the entire protein patterns were analyzed by nano-ESI-MS after cutting the different gel spots and in-gel trypsin digestion. A highly selective and specific tandem MS technique has been developed to characterize and localize up to ten lactosylation sites in beta-lactoglobulin (beta-Lg) and alpha(S2)-casein. alpha-Lactalbumin (alpha-La), with five lactosylated peptides, was found to be an interesting protein marker in the milk powder sample to detect chemical modification induced by the processing/storage conditions.
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Abstract
Lactational strategies and associated development of the young have been studied in a diverse range of species, and comparative analysis allows common trends and differences to be revealed. The whey fraction contains a vast number of proteins, many of which have not been assigned a function. However, it is expected that an understanding of the comparative biology of these proteins may provide some promise in assigning a function to the major whey proteins. Whey acidic protein is a major component of the whey fraction that has been studied across a range of species, revealing conservation of gene structure, whereas regulation and temporal expression patterns vary. This review focuses primarily on comparative analysis of whey acidic protein, highlighting gene structure, developmental and hormonal regulation, and potential functional roles for this protein. In addition, the contrasting regulation and secretion profiles of several other major whey proteins are discussed.
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Affiliation(s)
- Kaylene J Simpson
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Victoria, Australia.
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23
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Pintado ME, Malcata FX. Studies on genetic variants of α‐lactalbumin and β‐lactoglobulin from milk of native Portuguese ovine and caprine breeds. Int J Food Sci Technol 2001. [DOI: 10.1046/j.1365-2621.1999.00258.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Manuela E. Pintado
- Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr António Bernardino de Almeida, 4200 Porto, Portugal
| | - F. Xavier Malcata
- Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr António Bernardino de Almeida, 4200 Porto, Portugal
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Elidemir O, Fan LL, Colasurdo GN. A novel diagnostic method for pulmonary aspiration in a murine model. Immunocytochemical staining of milk proteins in alveolar macrophages. Am J Respir Crit Care Med 2000; 161:622-6. [PMID: 10714979 DOI: 10.1164/ajrccm.161.2.9906036] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Aspiration of foreign material into the lungs has been implicated in the etiology of a variety of pulmonary disorders. Although aspiration is a common clinical problem, its diagnosis represents a major challenge due to the lack of sensitive and/or specific tests. In this study, we evaluated the sensitivity and specificity of a novel diagnostic method in a murine model of milk aspiration. Under light anesthesia, BALB/c mice received either single or repeated intranasal instillation of milk. Control animals received sterile physiologic saline or were infected with respiratory pathogens in a similar manner. After isolation and cannulation of the trachea, mouse lungs were lavaged with PBS at various time points after the last aspiration event. Cells were recovered for Oil Red O (ORO) staining as well as immunocytochemistry for milk proteins: alpha-lactalbumin and beta-lactoglobulin. After single aspiration of milk, a large number of alveolar macrophages displayed a strong immunoreactivity for alpha-lactalbumin for 2-96 h. After single and repeated aspiration, the percentage of positive cells for alpha-lactalbumin was significantly higher when compared with ORO staining at 24, 48, and 72 h (p < 0.05). No immunoreactivity for milk proteins was found in alveolar macrophages obtained from our control groups. These findings demonstrate that immunocytochemical staining of milk proteins within alveolar macrophages represents a novel, sensitive, and specific test for the diagnosis of aspiration in a murine model.
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Affiliation(s)
- O Elidemir
- Department of Pediatrics, Division of Pulmonary Medicine, Baylor College of Medicine, University of Texas-Houston Medical School, Houston, Texas 77030, USA
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Schmidt M, Radovic B, Lipp M, Harzer G, Anklam E. Characterisation of milk samples with various whey protein contents by pyrolysis–mass spectrometry (Py–MS). Food Chem 1999. [DOI: 10.1016/s0308-8146(98)00169-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Murakami K, Lagarde M, Yuki Y. Identification of minor proteins of human colostrum and mature milk by two-dimensional electrophoresis. Electrophoresis 1998; 19:2521-7. [PMID: 9820977 DOI: 10.1002/elps.1150191427] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Two-dimensional electrophoresis (2-DE) followed by electroblotting and microsequencing is considered to be the most powerful method for the isolation and characterization of proteins. In this paper, we report the separation and determination of the N-terminal and/or internal amino acid sequences of the minor proteins of human colostral and mature milk by 2-DE and microsequencing. In order to analyze the minor proteins of human milk, we use immunoabsorbents to remove three major proteins, alpha-lactalbumin, lactoferrin and secretory immunoglobulin A. The major proteins removed by this process accounted for about 79 and 93% of the total whey proteins of mature and colostral milk, respectively. The remaining milk proteins were then separated by isoelectric focusing gel electrophoresis between pH 3 and 10, and subjected to 12.5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Approximately 400 spots were detected in both colostral and mature milk by silver staining after 2-DE. Twenty-two major, well-resolved proteins (out of 400) were microsequenced (N-termini as well as internal). These include fatty acid binding protein, beta 2-microglobulin, complement C4, clusterin, alpha 1-antritrypsin, lysozyme C, alpha- and beta-casein, prealbumin, serotransferrin, fructose-bisphosphate aldolase A, and beta-casein fragments. No major differences in the protein patterns were observed between the minor proteins of colostrum and mature milk, indicating that the minor proteins remained relatively constant during lactation. These results suggest that the minor milk proteins are important for the health and development of breast-fed infants throughout lactation.
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Affiliation(s)
- K Murakami
- JCR Biopharmaceuticals Inc., San Diego, CA 92121, USA
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Abstract
Hepatitis C virus (HCV) has two envelope proteins, E1 and E2, which form a heterooligomer. During dissection of interacting regions of HCV E1 and E2, we found the presence of an interfering compound or compounds in skim milk. Here we report that human as well as bovine lactoferrin, a multifunctional immunomodulator, binds two HCV envelope proteins. As determined by far-Western blotting, the bacterially expressed E1 and E2 could bind lactoferrin in human milk directly separated or immunopurified and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The bindings of lactoferrin and HCV envelope proteins in vitro were confirmed by another method, the pull-down assay, with immunoprecipitated lactoferrin-bound protein A resin. By the same assay, mammal-expressed recombinant E1 and E2 were also demonstrated to bind human lactoferrin efficiently in vitro. Direct interaction between E2 and lactoferrin was proved in vivo, since anti-human lactoferrin antibody efficiently coimmunoprecipitated with secreted and intracellular forms of the E2 protein, but not glutathione S-transferase (GST), from lysates of HepG2 cells transiently cotransfected with the expression plasmids of human lactoferrin and gE2t-GST (the N-terminal two-thirds of E2 fused to GST) or GST. The N-terminal loop of lactoferrin, the region important for the antibacterial activity, has only a little role in the binding ability to HCV E2 but affected the secretion or stability of lactoferrin. Taken together, these results indicate the specific interaction between lactoferrin and HCV envelope proteins in vivo and in vitro.
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Affiliation(s)
- M Yi
- Department of Molecular Biology, Medical School, Kanazawa University, Takara-Machi, Japan
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