1
|
Timlin M, Brodkorb A, Harbourne N, O'Callaghan TF, Drouin G, Pacheco-Pappenheim S, Hennessy D, O'Donovan M, Pierce KM, Corrigan BM, Murphy JP, Pismennõi D, Taivosalo A, Lints T, Kriščiunaite T, Vilu R, Fitzpatrick E, McCarthy K, Sheehan JJ. The impact of seasonal calving systems with varying pasture allowance on Cheddar cheese composition, nutritional quality and ripening characteristics. J Dairy Sci 2024:S0022-0302(24)01056-7. [PMID: 39122152 DOI: 10.3168/jds.2024-24745] [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: 02/01/2024] [Accepted: 07/16/2024] [Indexed: 08/12/2024]
Abstract
The objective of this study was to examine the impact of stage of lactation (early, mid and late) and proportion of pasture in the cows diet (high: GRS, medium: PMR and no: TMR) on the composition and quality of Cheddar cheese. Triplicate trials were carried out in each stage of lactation, and milk protein and fat contents were standardized for Cheddar cheese manufacture at pilot scale. As cheese milks were standardized for milk fat and protein contents, gross composition did not differ as a result of diet. Fatty acid profiles of GRS cheese were significantly different from TMR, while PMR profiles were less distinct and more similar to both GRS and TMR profiles, as illustrated by partial least squares discriminatory analysis. Fatty acids including CLA C18:2 cis-9, trans-11, C22:1 n-9 and C18:3 n-3 were most influential in this separation of profiles. Fatty acid profiling revealed that GRS derived cheese contained higher proportions of nutrients considered beneficial for human health including higher proportions of unsaturated fatty acids and omega-3 fatty acids. A biomarker model utilizing the proportions of 5 fatty acids was constructed and was effective at distinguishing between cheese of GRS, TMR and PMR feeding systems. Proportions of ρ-κ-casein, αs2-casein and αs1-casein in cheese also differed between diets while proportions of ρ-κ-casein, αs1-casein and β-casein were lowest in late lactation cheese. The impact of diet was less influential compared with that of stage of lactation on the ripening characteristics of cheese. An index of primary proteolysis was highest in late lactation cheese. The peptides derived from the proteolysis of κ-casein and β-casein and levels of secondary proteolysis, in particular, the proportions of 12 free amino acids were most influenced by stage of lactation. Overall this study demonstrated the effects of increasing pasture allowance and stage of lactation on the nutritional quality and ripening properties of Cheddar cheese.
Collapse
Affiliation(s)
- Mark Timlin
- Teagasc, Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 C996; School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland. D04 V1W8; Food for Health Ireland, University College Dublin, Dublin 4, Ireland. D04 V1W8
| | - André Brodkorb
- Teagasc, Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 C996; Food for Health Ireland, University College Dublin, Dublin 4, Ireland. D04 V1W8
| | - Niamh Harbourne
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland. D04 V1W8
| | - Tom F O'Callaghan
- School of Food and Nutritional Sciences, University College Cork, Cork, Ireland. T12 K8AF
| | - Gaetan Drouin
- Teagasc, Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 C996
| | | | - Deirdre Hennessy
- Teagasc Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 P302; School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland. T23 N73K
| | - Michael O'Donovan
- Teagasc Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 P302
| | - Karina M Pierce
- School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland. D04 V1W8; Food for Health Ireland, University College Dublin, Dublin 4, Ireland. D04 V1W8
| | - Bernard M Corrigan
- Teagasc, Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 C996
| | - John P Murphy
- Teagasc Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 P302
| | - Dmitri Pismennõi
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618, Tallinn, Estonia
| | - Anastassia Taivosalo
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618, Tallinn, Estonia
| | - Taivo Lints
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618, Tallinn, Estonia
| | - Tiina Kriščiunaite
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618, Tallinn, Estonia
| | - Raivo Vilu
- Center of Food and Fermentation Technologies (TFTAK), Mäealuse 2/4, 12618, Tallinn, Estonia
| | - Ellen Fitzpatrick
- Teagasc Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 P302; Teagasc, Environmental Research Centre, Johnstown Castle, Wexford, Ireland. Y35 Y521
| | - Kieran McCarthy
- Teagasc Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 P302
| | - Jeremiah J Sheehan
- Teagasc, Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland. P61 C996; Food for Health Ireland, University College Dublin, Dublin 4, Ireland. D04 V1W8.
| |
Collapse
|
2
|
Hassanin AA, Osman A, Atallah OO, El-Saadony MT, Abdelnour SA, Taha HSA, Awad MF, Elkashef H, Ahmed AE, Abd El-Rahim I, Mohamed A, Eldomiaty AS. Phylogenetic comparative analysis: Chemical and biological features of caseins (alpha-S-1, alpha-S-2, beta- and kappa-) in domestic dairy animals. Front Vet Sci 2022; 9:952319. [PMID: 36187819 PMCID: PMC9519386 DOI: 10.3389/fvets.2022.952319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/11/2022] [Indexed: 11/25/2022] Open
Abstract
Caseins determine the physicochemical, physiological, and biological characteristics of milk. Four caseins—alpha-S-1, alpha-S-2, beta, and kappa—were analyzed phylogenetically and in silico and characterized regarding chemical, antimicrobial, and antioxidant features in five dairy animals: Arabian camels, sheep, goats, cattle, and water buffalos. The sequence of full-length amino acids of the four caseins for the five species was retracted from the NCBI GenBank database. Multiple sequence alignment is used to examine further the candidate sequences for phylogenetic analysis using Clustal X and NJ-Plot tools. The results revealed that sheep and goats possess strong similarities (98.06%) because of their common ancestor. The same was observed with cattle and water buffalos (96.25%). The Arabian camel was located in a single subclade due to low similarity in casein residues and compositions with other dairy animals. Protein modeling showed that alpha-S1- and alpha-S2-caseins possess the highest number of phosphoserine residues. The in silico computed chemical properties showed that β-casein recorded highest hydrophobicity index and lowest basic amino acid content, while α-S2-casein showed the opposite. The computed biological parameters revealed that α-S2-casein presented the highest bactericidal stretches. Only Arabian camel β-casein and k-casein showed one bactericidal stretches. The analysis also revealed that β-casein, particularly in Arabian camels, possesses the highest antioxidant activity index. These results support the importance of the bioinformatics resources to determine milk casein micelles' chemical and biological activities.
Collapse
Affiliation(s)
- Abdallah A. Hassanin
- Genetics Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
- *Correspondence: Abdallah A. Hassanin
| | - Ali Osman
- Department of Biochemistry, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Osama Osman Atallah
- Department of Plant Pathology, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Mohamed T. El-Saadony
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
- Mohamed T. El-Saadony
| | - Sameh A. Abdelnour
- Animal Production Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Heba S. A. Taha
- Genetics Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Mohamed F. Awad
- Department of Biology, College of Science, Taif University, Taif, Saudi Arabia
| | - Hany Elkashef
- Dairy Department, Faculty of Agriculture, Cairo University, Giza, Egypt
| | - Ahmed Ezzat Ahmed
- Department of Biology, College of Science, King Khalid University, Abha, Saudi Arabia
- Department of Theriogenology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Ibrahim Abd El-Rahim
- Department of Environmental and Health Research, Umm Al-Qura University, Mecca, Saudi Arabia
- Infectious Diseases, Department of Animal Medicine, Faculty of Veterinary Medicine, Assiut University, Asyut, Egypt
| | | | - Ahmed S. Eldomiaty
- Genetics Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| |
Collapse
|
3
|
Nutritional Profile, Processing and Potential Products: A Comparative Review of Goat Milk. DAIRY 2022. [DOI: 10.3390/dairy3030044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Goat milk contains an abundance of different macro and micro-nutrients. Compared with other milk, goat milk is a viable option due to its low allergy levels and is preferred for infants with cow milk allergies. A wide variety of goat milk-based products, including yoghurt, ice cream, fermented milk, and cheese, are available on the market. They are produced using effective processing technology and are known to exhibit numerous health benefits after consumption. However, goat milk consumption is limited in many nations (compared with cow, buffalo, camel, and sheep milk) due to a lack of awareness of its nutritional composition and the significance of its different byproducts. This review provides a detailed explanation of the various macronutrients that may be present, with special attention paid to each component, its purpose, and the health benefits it offers. It also compares goat milk with milk from other species in terms of its superiority and nutritional content, as well as the types, production methods, health advantages, and other beneficial properties of the various goat milk products that are currently available on the market.
Collapse
|
4
|
Duerasch A, Konieczny M, Henle T. Identification of the initial reactive sites of micellar and non-micellar casein exposed to microbial transglutaminase. Eur Food Res Technol 2022. [DOI: 10.1007/s00217-022-04069-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractTo investigate the influence of the internal micellar structure on the course of enzymatic cross-linking especially in the initial phase of the reaction, casein micelles isolated from raw milk via ultracentrifugation were incubated with microbial transglutaminase (mTG) in comparison with non-micellar sodium caseinate. Reactive lysine and glutamine residues were identified using a label-free approach, based on the identification of isopeptides within tryptic hydrolysates by targeted HRMS as well as manual monitoring of fragmentation spectra. Identified reactive sites were furthermore weighted by tracking the formation of isopeptides over an incubation time of 15, 30, 45 and 60 min, respectively. Fifteen isopeptides formed in the early stage of mTG cross-linking of caseins were identified and further specified concerning the position of lysine and glutamine residues involved in the reaction. The results revealed lysine K176 and glutamine Q175 of β-casein as the most reactive residues, which might be located in a highly flexible region of the molecule based on different possible reaction partners identified in this study. Except for the isopeptide αs1 K34–αs2 Q101 in sodium caseinate (SC), all reactive sites were detected in micellar and in non-micellar casein, indicating that the initial phase of enzymatic cross-linking is not affected by micellar aggregation of caseins.
Graphical abstract
Collapse
|
5
|
Auzino B, Miranda G, Henry C, Krupova Z, Martini M, Salari F, Cosenza G, Ciampolini R, Martin P. Top-Down proteomics based on LC-MS combined with cDNA sequencing to characterize multiple proteoforms of Amiata donkey milk proteins. Food Res Int 2022; 160:111611. [DOI: 10.1016/j.foodres.2022.111611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 06/08/2022] [Accepted: 06/29/2022] [Indexed: 11/24/2022]
|
6
|
Pan Z, Ye A, Dave A, Fraser K, Singh H. Kinetics of heat-induced interactions among whey proteins and casein micelles in sheep skim milk and aggregation of the casein micelles. J Dairy Sci 2022; 105:3871-3882. [DOI: 10.3168/jds.2021-21444] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 01/17/2022] [Indexed: 11/19/2022]
|
7
|
Gazi I, Franc V, Tamara S, van Gool MP, Huppertz T, Heck AJ. Identifying glycation hot-spots in bovine milk proteins during production and storage of skim milk powder. Int Dairy J 2022. [DOI: 10.1016/j.idairyj.2022.105340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
8
|
Comparative Peptidomics Analysis of Fermented Milk by Lactobacillus delbrueckii ssp. bulgaricus and Lactobacillus delbrueckii ssp. lactis. Foods 2021; 10:foods10123028. [PMID: 34945579 PMCID: PMC8701751 DOI: 10.3390/foods10123028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/19/2021] [Accepted: 12/01/2021] [Indexed: 12/01/2022] Open
Abstract
Few studies have investigated the peptidomics of fermented milk by Lactobacillus delbrueckii. The aim of the present study was to interpret the peptidomic pattern of the fermented milk by five strains of L. delbrueckii ssp. bulgaricus and ssp. lactis prior to and after the simulated gastrointestinal digestion in vitro. The results indicated variations in the peptidomics among the samples, particularly between the samples of different subspecies. The peptides originating from β-casein were abundant in the samples of ssp. bulgaricus, whereas the peptides derived from αs1-casein and αs2-casein were more likely to dominate in those of ssp. lactis. For β-casein, the strains of ssp. bulgaricus displayed extensive hydrolysis in the regions of (73–97), (100–120), and (130–209), whereas ssp. lactis mainly focused on (160–209). The digestion appears to reduce the variations of the peptidomics profile in general. Among the five strains, L. delbrueckii ssp. bulgaricus DQHXNS8L6 was the most efficient in the generation of bioactive peptides prior to and after digestion. This research provided an approach for evaluating the peptide profile of the strains during fermentation and digestion.
Collapse
|
9
|
Mohsin AZ, Sukor R, Selamat J, Meor Hussin AS, Ismail IH, Jambari NN, Jonet A. A highly selective two-way purification method using liquid chromatography for isolating α S2-casein from goat milk of five different breeds. J Chromatogr B Analyt Technol Biomed Life Sci 2020; 1160:122380. [PMID: 32971369 DOI: 10.1016/j.jchromb.2020.122380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 07/27/2020] [Accepted: 09/07/2020] [Indexed: 12/22/2022]
Abstract
The main challenges in the purification of αS2-casein are due to the low quantity in milk and high homology with other casein subunits, i.e., αS1-casein, β-casein, and κ-casein. To overcome these challenges, the aim of this study was to develop a two-step purification to isolate native αS2-casein in goat milk from five different breeds; British Alpine, Jamnapari, Saanen, Shami, and Toggenburg. The first step of the purification was executed by anion-exchange chromatography under optimal elution conditions followed by size exclusion chromatography. Tryptic peptides from in-gel digestion of purified αS2-casein were sequenced and analyzed by LC-ESI-MS/MS. From 1.05 g of whole casein, the highest yield of αS2-casein (6.7 mg/mL) was obtained from Jamnapari and the lowest yield (2.2 mg/mL) was from Saanen. A single band of pure αS2-casein was observed on SDS-PAGE for all breeds. The αS2-casein showed coverage percentage of amino acid sequence from 76.68 to 92.83%. The two-step purification process developed herein was successfully applied for isolating native αS2-casein from goat milk with high purity, which will allow for future in vitro studies to be conducted on this protein.
Collapse
Affiliation(s)
- Aliah Zannierah Mohsin
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
| | - Rashidah Sukor
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia.
| | - Jinap Selamat
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
| | - Anis Shobirin Meor Hussin
- Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
| | - Intan Hakimah Ismail
- Faculty of Medicine, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
| | - Nuzul Noorahya Jambari
- Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia; Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
| | - Anuar Jonet
- Department of Structural Biology and Biophysics, Malaysia Genome Institute, Kajang 43000, Selangor, Malaysia
| |
Collapse
|
10
|
Kusova AM, Sitnitsky AE, Faizullin DA, Zuev YF. Protein Translational Diffusion and Intermolecular Interactions of Globular and Intrinsically Unstructured Proteins. J Phys Chem A 2019; 123:10190-10196. [DOI: 10.1021/acs.jpca.9b08601] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Aleksandra M. Kusova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Lobachevsky Str., 2/31, Kazan 420111, Russian Federation
| | - Aleksandr E. Sitnitsky
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Lobachevsky Str., 2/31, Kazan 420111, Russian Federation
| | - Dzhigangir A. Faizullin
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Lobachevsky Str., 2/31, Kazan 420111, Russian Federation
- Kazan (Volga Region) Federal University, Kremlevskaya Str., 18, Kazan 420021, Russian Federation
| | - Yuriy F. Zuev
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Lobachevsky Str., 2/31, Kazan 420111, Russian Federation
- Kazan (Volga Region) Federal University, Kremlevskaya Str., 18, Kazan 420021, Russian Federation
| |
Collapse
|
11
|
Ettah I, Ashton L. Determination of Phosphorylation and Deprotonation Induced Higher Order Structural Transitions in αs-Caseins. Anal Chem 2019; 91:13940-13946. [DOI: 10.1021/acs.analchem.9b03457] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Ilokugbe Ettah
- Department of Chemistry, Lancaster University, Lancaster, Lancashire LA1 4YB, United Kingdom
| | - Lorna Ashton
- Department of Chemistry, Lancaster University, Lancaster, Lancashire LA1 4YB, United Kingdom
| |
Collapse
|
12
|
Zhang C, Bijl E, Svensson B, Hettinga K. The Extracellular Protease AprX fromPseudomonasand its Spoilage Potential for UHT Milk: A Review. Compr Rev Food Sci Food Saf 2019; 18:834-852. [DOI: 10.1111/1541-4337.12452] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 03/06/2019] [Accepted: 03/10/2019] [Indexed: 01/10/2023]
Affiliation(s)
- Chunyue Zhang
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
| | - Etske Bijl
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
| | - Birgitta Svensson
- Tetra Pak Processing Systems ABRuben Rausings gata 221 86 Lund Sweden
| | - Kasper Hettinga
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
| |
Collapse
|
13
|
Ryskaliyeva A, Henry C, Miranda G, Faye B, Konuspayeva G, Martin P. Alternative splicing events expand molecular diversity of camel CSN1S2 increasing its ability to generate potentially bioactive peptides. Sci Rep 2019; 9:5243. [PMID: 30918277 PMCID: PMC6437144 DOI: 10.1038/s41598-019-41649-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 03/14/2019] [Indexed: 02/08/2023] Open
Abstract
In a previous study on camel milk from Kazakhstan, we reported the occurrence of two unknown proteins (UP1 and UP2) with different levels of phosphorylation. Here we show that UP1 and UP2 are isoforms of camel αs2-CN (αs2-CNsv1 and αs2-CNsv2, respectively) arising from alternative splicing events. First described as a 178 amino-acids long protein carrying eight phosphate groups, the major camel αs2-CN isoform (called here αs2-CN) has a molecular mass of 21,906 Da. αs2-CNsv1, a rather frequent (35%) isoform displaying a higher molecular mass (+1,033 Da), is present at four phosphorylation levels (8P to 11P). Using cDNA-sequencing, αs2-CNsv1 was shown to be a variant arising from the splicing-in of an in-frame 27-nucleotide sequence encoding the nonapeptide ENSKKTVDM, for which the presence at the genome level was confirmed. αs2-CNsv2, which appeared to be present at 8P to 12P, was shown to include an additional decapeptide (VKAYQIIPNL) revealed by LC-MS/MS, encoded by a 3'-extension of exon 16. Since milk proteins represent a reservoir of biologically active peptides, the molecular diversity generated by differential splicing might increase its content. To evaluate this possibility, we searched for bioactive peptides encrypted in the different camel αs2-CN isoforms, using an in silico approach. Several peptides, putatively released from the C-terminal part of camel αs2-CN isoforms after in silico digestion by proteases from the digestive tract, were predicted to display anti-bacterial and antihypertensive activities.
Collapse
Affiliation(s)
- Alma Ryskaliyeva
- INRA, UMR GABI, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Céline Henry
- INRA, MICALIS Institute, Plateforme d'Analyse Protéomique Paris Sud-Ouest (PAPPSO), Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Guy Miranda
- INRA, UMR GABI, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Bernard Faye
- CIRAD, UMR SELMET, 34398, Montpellier Cedex 5, France
| | - Gaukhar Konuspayeva
- Al-Farabi Kazakh National University, Biotechnology department, 050040, Almaty, Kazakhstan
| | - Patrice Martin
- INRA, UMR GABI, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France.
| |
Collapse
|
14
|
Melnikova DL, Skirda VD, Nesmelova IV. Effect of Reducing Agent TCEP on Translational Diffusion and Supramolecular Assembly in Aqueous Solutions of α-Casein. J Phys Chem B 2019; 123:2305-2315. [PMID: 30789730 DOI: 10.1021/acs.jpcb.8b12511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The translational diffusion coefficient is highly sensitive to the size change of diffusing species and is ideally suited for the study of molecular association. Here, we used translational diffusion measurements by a pulsed-field gradient nuclear magnetic resonance (PFG NMR) technique to investigate the role of disulfide bonds in the formation of a supramolecular gel-like structure in the concentrated solution of α-casein. To reduce disulfide bonds, we added a commonly used reducing reagent tris(2-carboxyethyl)phosphine (TCEP) to α-casein solution. We found that the disruption of a disulfide bond Cys36-Cys40 in αs2-casein does not alter the translational diffusion or secondary structure of α-casein in dilute, 1 and 3% (wt %) solution. On the contrary, in concentrated, 15% (wt %) α-casein solution, in addition to the disruption of disulfide bonds, TCEP induced significant changes in gel properties. New long-lived intermolecular interactions formed, leading to the irreversible gel formation. While a few side reactions of TCEP (as well as other reducing agents, e.g., dithiothreitol) have been reported, this area is still understudied. Here, we provide new data on the side reaction of the reducing agent TCEP in concentrated protein solution, suggesting that at high protein concentrations TCEP should be used with caution.
Collapse
Affiliation(s)
- Daria L Melnikova
- Department of Physics , Kazan Federal University , Kazan 420011 , Russia
| | - Vladimir D Skirda
- Department of Physics , Kazan Federal University , Kazan 420011 , Russia
| | | |
Collapse
|
15
|
Carver JA, Holt C. Functional and dysfunctional folding, association and aggregation of caseins. PROTEIN MISFOLDING 2019; 118:163-216. [DOI: 10.1016/bs.apcsb.2019.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
16
|
Modification of IgE binding to α S1-casein by proteolytic activity of Enterococcus faecium isolated from Iranian camel milk samples. J Biotechnol 2018; 276-277:10-14. [PMID: 29669265 DOI: 10.1016/j.jbiotec.2018.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 01/02/2023]
Abstract
Milk is a perfect source of nutrients for neonates. When breast feeding cannot be done, an infant's alimentation is usually initiated to cow's milk, among the primary foods. It has been reported that about 2.5% of juveniles under the age of 3 years manifest allergic reactions to cow's milk proteins. Among the cow's milk proteins, casein fractions are considered as the strongest allergenic proteins. The proteolytic enzymes of lactic acid bacteria (LAB), during fermentation of dairy products, can break down milk proteins especially caseins and subsequently reduce the immune reactivity of allergenic proteins. In this research, raw bovine and camel milk samples were screened for cocci LAB strains and after isolation, their proteolytic activity against bovine milk caseins were evaluated by SDS-PAGE and RP-HPLC. The potential of cocci LAB strains on αS1-casein degradation and their potential to break down the principle allergenic epitopes of this protein was detected using indirect competitive ELISA. Molecular identification of the best proteolytic strain was fulfilled by 16S rDNA fragment sequencing with universal primers. The obtained results demonstrated that Enterococcus faecium isolated from raw camel milk samples was the most efficient isolate in hydrolyzing Na-caseinate and αS1-casein. Hydrolysated αS1-casein by Enterococcus faecium was also less recognized by IgE of bovine milk allergic patients' sera in comparison with native αS1-casein. It has been proposed that Enterococcus faecium could be an efficient strain in allergenicity reduction of cow's milk proteins. So it could be an excellent candidate to be potentially used in dairy industries.
Collapse
|
17
|
|
18
|
Mediwaththe A, Chandrapala J, Vasiljevic T. Shear-induced behaviour of native milk proteins heated at temperatures above 80 °C. Int Dairy J 2018. [DOI: 10.1016/j.idairyj.2017.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
19
|
Taivosalo A, Kriščiunaite T, Seiman A, Part N, Stulova I, Vilu R. Comprehensive analysis of proteolysis during 8 months of ripening of high-cooked Old Saare cheese. J Dairy Sci 2017; 101:944-967. [PMID: 29174156 DOI: 10.3168/jds.2017-12944] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 09/03/2017] [Indexed: 11/19/2022]
Abstract
We applied capillary electrophoresis, liquid chromatography coupled with tandem mass-spectrometry (MS/MS), and ultra-performance liquid chromatography to determine the composition of water-insoluble and water-soluble proteinaceous fractions of the cheese and to study in detail the degradation of caseins during 8 mo of ripening of Estonian high-temperature cooked hard cheese Old Saare. The application of high-resolution and high-accuracy MS/MS enabled identification of more than 3,000 small peptides, representing a fairly full casein peptidome containing peptides of 4 to 25 AA in length: 1,049 from β-casein (CN), 944 from αS1-CN, 813 from αS2-CN, and 234 from κ-CN. The majority of β-CN- and αS1-CN-derived peptides originated from the N-terminal parts of the molecule, f6-93 and f1-124, respectively; peptides from αS2-CN arose predominantly from the C-terminal end f100-162. At the beginning of ripening, we found a relatively high amount of peptides originating from the glycomacropeptide part of κ-CN, whereas peptides from para-κ-CN prevailed during the later stages of ripening of the cheese. The cleavage patterns of β-CN, αS2-CN, as well as αS1-CN, showed that primary proteolysis was started mainly by plasmin, although a low proteolytic activity of chymosin was also evident. Based on the analysis of cleavage sites, we observed a significant participation of proteolytic enzymes, including amino- and carboxypeptidases, of both mesophilic and thermophilic starter bacteria in further hydrolysis of oligopeptides during the ripening. Several new phosphopeptides were detected in the result of MS/MS data analysis. The profiles of the estimated concentrations of phosphopeptides revealed that those originating from β-CN and αS1-CN accumulated during cheese maturation. In contrast, we did not notice any generation of phosphopeptides from the highly phosphorylated part of αS2-CN, f25-80, presumably due to the inaccessibility of this region to the action of plasmin and chymosin. The analysis of cleavage sites and the combination of principal component and clustering analyses provided a characterization of the complex dynamics of formation and degradation of peptides during cheese maturation. We made an attempt to obtain a comprehensive picture of proteolysis during Old Saare cheese ripening on the basis of the detailed peptidomic data, including also the less abundant peptides determined by MS/MS, and complemented by the data on intact caseins and free AA and reported the results in the paper.
Collapse
Affiliation(s)
- A Taivosalo
- Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618 Tallinn, Estonia; Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia.
| | - T Kriščiunaite
- Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618 Tallinn, Estonia
| | - A Seiman
- Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618 Tallinn, Estonia; Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| | - N Part
- Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618 Tallinn, Estonia
| | - I Stulova
- Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618 Tallinn, Estonia
| | - R Vilu
- Center of Food and Fermentation Technologies, Akadeemia tee 15A, 12618 Tallinn, Estonia; Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, Estonia
| |
Collapse
|
20
|
|
21
|
Kim JJ, Yu J, Bag J, Bakovic M, Cant JP. Translation attenuation via 3' terminal codon usage in bovine csn1s2 is responsible for the difference in αs2- and β-casein profile in milk. RNA Biol 2015; 12:354-67. [PMID: 25826667 DOI: 10.1080/15476286.2015.1017231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The rate of secretion of αs2-casein into bovine milk is approximately 25% of that of β-casein, yet mammary expression of their respective mRNA transcripts (csn1s2 and csn2) is not different. Our objective was to identify molecular mechanisms that explain the difference in translation efficiency between csn1s2 and csn2. Cell-free translational efficiency of csn2 was 5 times that of csn1s2. Transcripts of csn1s2 distributed into heavier polysomes than csn2 transcripts, indicating an attenuation of elongation and/or termination. Stimulatory and inhibitory effects of the 5' and 3' UTRs on translational efficiency were different with luciferase and casein sequences in the coding regions. Substituting the 5' and 3' UTRs from csn2 into csn1s2 did not improve csn1s2 translation, implicating the coding region itself in the translation difference. Deletion of a 28-codon fragment from the 3' terminus of the csn1s2 coding region, which displays codons with low correlations to cell fitness, increased translation to a par with csn2. We conclude that the usage of the last 28 codons of csn1s2 is the main regulatory element that attenuates its expression and is responsible for the differential translational expression of csn1s2 and csn2.
Collapse
Key Words
- 40S, small ribosomal subunit
- 60S, large ribosomal subunit
- AA, amino acid
- ARE, AU-rich element
- Apaf-1, apoptosis protease activating factor 1
- DLG1, disc large 1 ncosuppressor
- FMR1, fragile X mental retardation 1
- HRP, horseradish eroxidase
- IE, inhibitory element
- IRE, iron-responsive element
- IRES, nternal ribosome entry site
- IRP, iron-regulatory protein
- MACT, bovine mammary epithelial cell
- PABP, poly(A) binding protein
- PAGE, polyacrylamide gel electrophoresis
- PCR, polymerase chain reaction
- PVDF, polyvinylidene fluoride
- RACE, rapid amplification of cDNA ends
- RBP, RNA-binding protein
- RRL, rabbit reticulocyte lysate
- RT, reverse transcription
- SDS, sodium dodecyl sulfate
- SE, standard error
- STR, single-stranded nucleic acid binding protein
- TBS-T, Tris-buffered saline containing 0.5%
- TfR, transferrin receptor
- Tween 20
- UTR, untranslated region
- aa-tRNA, aminoacyl-tRNA
- aaRS, aminoacyl-tRNA synthetase
- bovine casein
- cDNA, complementary DNA
- cell-free translation
- coding region
- codon usage
- eEF, eukaryotic elongation factor
- eIF, eukaryotic initiation factor
- eRF, eukaryotic termination factor
- m7G, 7-methylated uanidine
- mRNA, messenger RNA
- qPCR, real-time polymerase chain reaction
- sAUG, start codon
- tRNA, transfer RNA
- translational efficiency
- uAUG, upstream start codon
- uORF, open reading frame
- untranslated region
- ΔG, free energy
Collapse
Affiliation(s)
- Julie J Kim
- a Animal and Poultry Science; University of Guelph ; Guelph , Ontario , Canada
| | | | | | | | | |
Collapse
|
22
|
Qu X, Cui Y, Yu T, Hu T, Wang C, Lv X, Ma Y. Detection of αS2-casein variants in Chinese yak (Bos grunniens) by PCR-SSCP. J Genet 2015; 94:e1-4. [PMID: 25810399 DOI: 10.1007/s12041-015-0468-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Xiaojun Qu
- School of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
| | | | | | | | | | | | | |
Collapse
|
23
|
Rauh VM, Johansen LB, Ipsen R, Paulsson M, Larsen LB, Hammershøj M. Plasmin activity in UHT milk: relationship between proteolysis, age gelation, and bitterness. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:6852-60. [PMID: 24964203 DOI: 10.1021/jf502088u] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plasmin, the major indigenous protease in milk, is linked to quality defects in dairy products. The specificity of plasmin on caseins has previously been studied using purified caseins and in the indigenous peptide profile of milk. We investigated the specificity and proteolytic pathway of plasmin in directly heated UHT milk (>150 °C for <0.2 s) during 14 weeks of storage at 20 °C in relation to age gelation and bitter peptides. Sixty-six peptides from αS- and β-caseins could be attributed to plasmin activity during the storage period, of which 23 were potentially bitter. Plasmin exhibited the highest affinity for the hydrophilic regions in the caseins that most probably were exposed to the serum phase and the least affinity for hydrophobic or phosphorylated regions. The proteolytic pattern observed suggests that plasmin destabilizes the casein micelle by hydrolyzing casein-casein and casein-calcium phosphate interaction sites, which may subsequently cause age gelation in UHT milk.
Collapse
Affiliation(s)
- Valentin M Rauh
- Arla Foods Strategic Innovation Centre , Rørdrumvej 2, DK-8220 Brabrand, Denmark
| | | | | | | | | | | |
Collapse
|
24
|
|
25
|
Belyamani I, Prochazka F, Assezat G. Production and characterization of sodium caseinate edible films made by blown-film extrusion. J FOOD ENG 2014. [DOI: 10.1016/j.jfoodeng.2013.08.019] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
26
|
Kishore A, Sodhi M, Mukesh M, Mishra BP, Sobti RC. Sequence analysis and identification of new variations in the 5'-flanking region of αS2-casein gene in Indian zebu cattle. Mol Biol Rep 2013; 40:4473-81. [PMID: 23657593 DOI: 10.1007/s11033-013-2539-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 04/29/2013] [Indexed: 10/26/2022]
Abstract
Regulatory region of milk protein alpha S2-casein (αS2-CN) gene sequence was characterized and analyzed for nucleotide variations in animals representing 13 Indian zebu cattle (Bos indicus) breeds. A total of 15 variations; 11 in promoter region (1.56 Kb): -1481 (C>T), -1412 (C>T), -1342 (C>T), -1084 (G>A), -979 (A>G), -657 (A>T), -508 (A>G), -186 (T>C), -184 (T>C), -151 (T>C) and -135 (C>T); 1 in 5'-UTR (44 bp): 7 (C>T) while, 3 in intron-I region (73 bp): 186 (C>T), 194 (A>C) and 301 (A>T) were identified. Additionally, single deletion was observed at -975 (A>-) but not involve any known potential transcription factor binding sites (TFBS). Comparison with Bos taurus sequence revealed two additional variations -1085 (T>C) and -739 (A>G). Out of the total 18 variations observed between indicine and taurine αS2-CN regulatory region sequence, 15 were novel to B. indicus and are reported for the first time. Among these, four variations were located within the potential TFBSs; -1342 (C>T) within HNF-3beta, -739 (A>G) within C/EBP-alpha while -657 (A>T) and -508 (A>G) were found within glucocorticoid receptor TFBSs. Variations located within or in proximity to putative TFBSs could possibly influence the binding affinity of nuclear factors towards DNA binding domains, thus affecting transcriptional rate of αS2-CN gene. Phylogenetically, as expected, Indian zebu cattle were grouped close to B. taurus and were most distantly placed in comparison to human. The study indicated possible genetic variations in the regulatory regions of αS2-CN gene within Indian native cattle (B. indicus) and also its comparison with evolutionary different B. taurus breeds.
Collapse
Affiliation(s)
- Amit Kishore
- Cattle Genomics Lab, National Bureau of Animal Genetics Resources, P.O. Box 129, Karnal, 132 001, Haryana, India
| | | | | | | | | |
Collapse
|
27
|
Abstract
Streptococcus(Str.)agalactiaeis a contagious mastitis bacterium, often associated with cases of subclinical mastitis. Different mastitis bacteria have been evaluated previously from a diagnostic point of view, but there is a lack of knowledge concerning their effect on milk composition. Protein composition is important in achieving optimal yield and texture when milk is processed to fermented products, such as cheese and yoghurt, and is thus of great economic value. The aim of thisin vitrostudy was to evaluate protein degradation mainly caused by exogenous proteases originating from naturally occurringStr. agalactiae. The samples were incubated at 37°C to imitate degradation caused by the bacteria in the udder. Protein degradation caused by different strains ofStr. agalactiaewas also investigated. Protein degradation was observed to occur whenStr. agalactiaewas added to milk, but there were variations between strains of the bacteria. Caseins, the most economically important proteins in milk, were degraded up to 75% in milk inoculated withStr. agalactiaein relation to sterile ultra-high temperature (UHT) milk, used as control milk. The major whey proteins, α-lactalbumin and β-lactoglobulin, were degraded up to 21% in relation to the sterile control milk. These results suggest that different mastitis bacteria but also different strains of mastitis bacteria should be evaluated from a milk quality perspective to gain knowledge about their ability to degrade the economically important proteins in milk.
Collapse
|
28
|
Abstract
The maintenance of the levels and correct folding state of proteins (proteostasis) is a fundamental prerequisite for life. Life has evolved complex mechanisms to maintain proteostasis and many of these that operate inside cells are now well understood. The same cannot yet be said of corresponding processes in extracellular fluids of the human body, where inappropriate protein aggregation is known to underpin many serious diseases such as Alzheimer's disease, type II diabetes and prion diseases. Recent research has uncovered a growing family of abundant extracellular chaperones in body fluids which appear to selectively bind to exposed regions of hydrophobicity on misfolded proteins to inhibit their toxicity and prevent them from aggregating to form insoluble deposits. These extracellular chaperones are also implicated in clearing the soluble, stabilized misfolded proteins from body fluids via receptor-mediated endocytosis for subsequent lysosomal degradation. Recent work also raises the possibility that extracellular chaperones may play roles in modulating the immune response. Future work will better define the in vivo functions of extracellular chaperones in proteostasis and immunology and pave the way for the development of new treatments for serious diseases.
Collapse
|
29
|
Simultaneous presence of PrtH and PrtH2 proteinases in Lactobacillus helveticus Strains improves breakdown of the pure alphas1-casein. Appl Environ Microbiol 2010; 77:179-86. [PMID: 21037305 DOI: 10.1128/aem.01466-10] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lactobacillus helveticus can possess one or two cell envelope proteinases (CEPs), called PrtH2 and PrtH. The aim of this work was to explore the diversity of 15 strains of L. helveticus, isolated from various origins, in terms of their proteolytic activities and specificities on pure caseins or on milk casein micelles. CEP activity differed 14-fold when the strains were assayed on a synthetic substrate, but no significant differences were detected between strains possessing one or two CEPs. No correlation was observed between the proteolytic activities of the strains and their rates of acidification in milk. The kinetics of hydrolysis of purified α(s1)- and β-casein by L. helveticus whole cells was monitored using Tris-Tricine sodium dodecyl sulfate (SDS) electrophoresis, and for four strains, the peptides released were identified using mass spectrometry. While rapid hydrolysis of pure β-casein was observed for all strains, the hydrolysis kinetics of α(s1)-casein was the only criterion capable of distinguishing between the strains based on the number of CEPs. Fifty-four to 74 peptides were identified for each strain. When only PrtH2 was present, 22 to 30% of the peptides originated from α(s1)-casein. The percentage increased to 41 to 49% for strains in which both CEPs were expressed. The peptide size ranged from 6 to 33 amino acids, revealing a broad range of cleavage specificities, involving all classes of amino acids (Leu, Val, Ala, Ile, Glu, Gln, Lys, Arg, Met, and Pro). Regions resistant to proteolysis were identified in both caseins. When strains were grown in milk, a drastic reduction in the number of peptides was observed, reflecting changes in accessibility and/or peptide assimilation during growth.
Collapse
|
30
|
Dabbs RA, Wyatt AR, Yerbury JJ, Ecroyd H, Wilson MR. Extracellular Chaperones. Top Curr Chem (Cham) 2010. [PMID: 21516385 DOI: 10.1007/128_2010_85] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The maintenance of the levels and correct folding state of proteins (proteostasis) is a fundamental prerequisite for life. Life has evolved complex mechanisms to maintain proteostasis and many of these that operate inside cells are now well understood. The same cannot yet be said of corresponding processes in extracellular fluids of the human body, where inappropriate protein aggregation is known to underpin many serious diseases such as Alzheimer's disease, type II diabetes and prion diseases. Recent research has uncovered a growing family of abundant extracellular chaperones in body fluids which appear to selectively bind to exposed regions of hydrophobicity on misfolded proteins to inhibit their toxicity and prevent them from aggregating to form insoluble deposits. These extracellular chaperones are also implicated in clearing the soluble, stabilized misfolded proteins from body fluids via receptor-mediated endocytosis for subsequent lysosomal degradation. Recent work also raises the possibility that extracellular chaperones may play roles in modulating the immune response. Future work will better define the in vivo functions of extracellular chaperones in proteostasis and immunology and pave the way for the development of new treatments for serious diseases.
Collapse
|
31
|
The dissociated form of κ-casein is the precursor to its amyloid fibril formation. Biochem J 2010; 429:251-60. [DOI: 10.1042/bj20091949] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bovine milk κ-casein forms a self-associating oligomeric micelle-like species, in equilibrium with dissociated forms. In its native form, intra- and inter-molecular disulfide bonds lead to the formation of multimeric species ranging from monomers to decamers. When incubated under conditions of physiological pH and temperature, both reduced and non-reduced κ-casein form highly structured β-sheet amyloid fibrils. We investigated whether the precursor to κ-casein fibril formation is a dissociated state of the protein or its oligomeric micelle-like form. We show that reduced κ-casein is capable of forming fibrils well below its critical micelle concentration, i.e. at concentrations where only dissociated forms of the protein are present. Moreover, by regulating the degree of disulfide linkages, we were able to investigate how oligomerization of κ-casein influences its propensity for fibril formation under conditions of physiological pH and temperature. Thus, using fractions containing different proportions of multimeric species, we demonstrate that the propensity of the disulfide-linked multimers to form fibrils is inversely related to their size, with monomeric κ-casein being the most aggregation prone. We conclude that dissociated forms of κ-casein are the amyloidogenic precursors to fibril formation rather than oligomeric micelle-like species. The results highlight the role of oligomerization and natural binding partners in preventing amyloid fibril formation by disease-related proteins in vivo.
Collapse
|
32
|
Mora-Gutierrez A, Attaie R, Farrell HM. Lipid oxidation in algae oil-in-water emulsions stabilized by bovine and caprine caseins. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:5131-5139. [PMID: 20232823 DOI: 10.1021/jf904343f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Caseins (alpha(s1)-, alpha(s2)-, and beta-casein) are phosphoproteins that are capable of binding transition metals and scavenging free radicals; this property makes them good candidates to be used as natural antioxidants in oil-in-water emulsions. Caprine casein exhibits variability in alpha(s1)-casein content generated by genetic polymorphism. This variability in composition could lead to altered antioxidant properties. Thus, the ability of two caprine caseins differing in alpha(s1)-casein content to inhibit lipid oxidation in algae oil-in-water emulsions at 5% oil was investigated and compared to bovine caseinate. All caseins inhibited the formation of lipid oxidation at pH 7.0 as determined by lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS). However, caprine caseins were in general more effective inhibitors of lipid oxidation than the bovine caseins, which may be attributed to their altered casein amino acid content and/or metal binding capabilities. The combination of the carotenoids with bovine and caprine caseins was highly effective at repressing oxidation leading to the speculation that the caseins may inhibit the loss of the carotenoids and/or react with and enhance the carotenoid activity; again some differences between bovine and caprine caseins were observed with caprine caseins being slightly more effective in the presence of carotenoids.
Collapse
Affiliation(s)
- Adela Mora-Gutierrez
- Cooperative Agricultural Research Center, Prairie View A&M University, Prairie View, Texas 77446, USA.
| | | | | |
Collapse
|