1
|
Van Rooyen B, De Wit M, Osthoff G, Van Niekerk J. Cactus Pear Mucilage ( Opuntia spp.) as a Novel Functional Biopolymer: Mucilage Extraction, Rheology and Biofilm Development. Polymers (Basel) 2024; 16:1993. [PMID: 39065310 PMCID: PMC11281074 DOI: 10.3390/polym16141993] [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: 04/30/2024] [Revised: 07/04/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024] Open
Abstract
The investigation of novel, natural polymers has gained considerably more exposure for their desirable, often specific, functional properties. Multiple researchers have explored these biopolymers to determine their potential to address many food processing, packaging and environmental concerns. Mucilage from the cactus pear (Opuntia ficus-indica) is one such biopolymer that has been identified as possessing a functional potential that can be used in an attempt to enhance food properties and reduce the usage of non-biodegradable, petroleum-based packaging in the food industry. However, variations in the structural composition of mucilage and the different extraction methods that have been reported by researchers have considerably impacted mucilage's functional potential. Although not comparable, these factors have been investigated, with a specific focus on mucilage applications. The natural ability of mucilage to bind water, alter the rheology of a food system and develop biofilms are considered the major applications of mucilage's functional properties. Due to the variations that have been reported in mucilage's chemical composition, specifically concerning the proportions of uronic acids, mucilage's rheological and biofilm properties are influenced differently by changes in pH and a cross-linker. Exploring the factors influencing mucilage's chemical composition, while co-currently discussing mucilage functional applications, will prove valuable when evaluating mucilage's potential to be considered for future commercial applications. This review article, therefore, discusses and highlights the key factors responsible for mucilage's specific functional potential, while exploring important potential food processing and packaging applications.
Collapse
Affiliation(s)
- Brandon Van Rooyen
- Department of Sustainable Food Systems and Development, University of the Free State, Bloemfontein 9301, South Africa
| | - Maryna De Wit
- Department of Sustainable Food Systems and Development, University of the Free State, Bloemfontein 9301, South Africa
| | - Gernot Osthoff
- Department of Microbiology and Biochemistry, University of the Free State, Bloemfontein 9301, South Africa
| | - Johan Van Niekerk
- Department of Sustainable Food Systems and Development, University of the Free State, Bloemfontein 9301, South Africa
| |
Collapse
|
2
|
Wang K, Crevel RWR, Mills ENC. An in vitro protocol to characterise the resistance of food proteins to intestinal digestion. Food Chem Toxicol 2023; 173:113590. [PMID: 36584934 DOI: 10.1016/j.fct.2022.113590] [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: 08/21/2022] [Revised: 12/23/2022] [Accepted: 12/24/2022] [Indexed: 12/28/2022]
Abstract
In vitro digestion tests provide data on the form in which dietary proteins maybe presented to the gut mucosal immune system, one of many strands of evidence used in allergenicity risk assessment. A 96-well plate format in vitro intestinal digestion protocol has been developed with a high and low enzyme activity test executed at pH 6.5 and 8.0. It was applied to the systematic analysis of test proteins (including six allergens and one non-allergenic comparator) which were either completely resistant to pepsinolysis or gave rise to large persistent fragments following in vitro gastric digestion. Digestion was monitored using SDS-PAGE and densitometry. Proteins resistant to pepsin were also resistant to intestinal digestion irrespective of the protocol applied and gave rise to large persistent digestion fragments. In contrast persistent fragments from pepsin digestion were readily digested. Bile salts enhanced the digestibility of two highly resistant proteins, lysozyme ad β-lactoglobulin, changing the rank order of protein digestibility. Intestinal digestion tests that include bile salts provide a more physiologically relevant system for future investigation into how digestion products may influence the balance between tolerance and sensitization - and hence contribute to future development of a more effective allergenicity risk assessment process.
Collapse
Affiliation(s)
- Kai Wang
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Manchester Institute of Biotechnology, 131 Princess Street, Manchester, M1 7DN, UK.
| | - Rene W R Crevel
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Manchester Institute of Biotechnology, 131 Princess Street, Manchester, M1 7DN, UK; René Crevel Consulting Ltd, 3 Woodlands Close, Cople, Bedford, MK44 3UE, UK.
| | - E N Clare Mills
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Manchester Institute of Biotechnology, 131 Princess Street, Manchester, M1 7DN, UK; School of Biosciences and Medicine, The University of Surrey, Guildford, UK.
| |
Collapse
|
3
|
Rodzik A, Król-Górniak A, Railean V, Sugajski M, Gołębiowski A, Horne DS, Michalke B, Sprynskyy M, Pomastowski P, Buszewski B. Study on zinc ions binding to the individual casein fractions: α-, β- and κ-casein. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.134251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
4
|
Grifnée E, Kune C, Delvaux C, Quinton L, Far J, Mazzucchelli G, De Pauw E. Label-Free Higher Order Structure and Dynamic Investigation Method of Proteins in Solution Using an Enzymatic Reactor Coupled to Electrospray High-Resolution Mass Spectrometry Detection. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:284-295. [PMID: 34969249 DOI: 10.1021/jasms.1c00274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
For decades, structural analysis of proteins have received considerable attention, from their sequencing to the determination of their 3D structures either in the free state (e.g., no host-guest system, apoproteins) or (non)covalently bound complexes. The elucidation of the 3D structures and the mapping of intra- and intermolecular interactions are valuable sources of information to understand the physicochemical properties of such systems. X-ray crystallography and nuclear magnetic resonance are methods of choice for obtaining structures at the atomic level. Nonetheless, they still present drawbacks which limit their use to highly purified systems in a relatively high amount. On the contrary, mass spectrometry (MS) has become a powerful tool thanks to its selectivity, sensitivity, and the development of structural methods both at the global shape and the residue level. The combination of several MS-based methods is mandatory to fully assign a putative structure in combination with computational chemistry and bioinformatics. In that context, we propose a strategy which complements the existing methods of structural studies (e.g., circular dichroism, hydrogen/deuterium exchange and cross-links experiments, nuclear magnetic resonance). The workflow is based on the collection of structural information on proteins from the apparition rates and the time of appearance of released peptides generated by a protease in controlled experimental conditions with online detection by electrospray high-resolution mass spectrometry. Nondenaturing, partially or fully denatured proteins were digested by the enzymatic reactor, i.e., β-lactoglobulin, cytochrome c, and β-casein. The collected data are interpreted with regard to the kinetic schemes with time-dependent rates of the enzymatic digestion established beforehand, considering kinetics parameters in the Michaelis-Menten formalism including kcat (the turnover number), k1 (formation of the enzyme-substrate complex), k-1 (dissociation of the enzyme-substrate complex), koff (local refolding of the protein around the cleavage site), and kon (local unfolding of the protein around the cleavage site). Solvent-accessible surface analysis through digestion kinetics was also investigated. The initial apparition rates of released peptides varied according to the protein state (folded vs denatured) and informs the koff/kon ratio around the cleavage site. On the other hand, the time of appearance of a given peptide is related to its solvent accessibility and to the resilience of the residual protein structure in solution. Temperature-dependent digestion experiments allowed estimation of the type of secondary structures around the cleavage site.
Collapse
Affiliation(s)
- Elodie Grifnée
- Mass Spectrometry Laboratory, MolSys Research Unit, Quartier Agora, University of Liège, Allée du Six Août 11, B-4000 Liège, Belgium
| | - Christopher Kune
- Mass Spectrometry Laboratory, MolSys Research Unit, Quartier Agora, University of Liège, Allée du Six Août 11, B-4000 Liège, Belgium
| | - Cédric Delvaux
- Mass Spectrometry Laboratory, MolSys Research Unit, Quartier Agora, University of Liège, Allée du Six Août 11, B-4000 Liège, Belgium
| | - Loïc Quinton
- Mass Spectrometry Laboratory, MolSys Research Unit, Quartier Agora, University of Liège, Allée du Six Août 11, B-4000 Liège, Belgium
| | - Johann Far
- Mass Spectrometry Laboratory, MolSys Research Unit, Quartier Agora, University of Liège, Allée du Six Août 11, B-4000 Liège, Belgium
| | - Gabriel Mazzucchelli
- Mass Spectrometry Laboratory, MolSys Research Unit, Quartier Agora, University of Liège, Allée du Six Août 11, B-4000 Liège, Belgium
| | - Edwin De Pauw
- Mass Spectrometry Laboratory, MolSys Research Unit, Quartier Agora, University of Liège, Allée du Six Août 11, B-4000 Liège, Belgium
| |
Collapse
|
5
|
Vigolo V, Franzoi M, Penasa M, De Marchi M. β-Casein variants differently affect bulk milk mineral content, protein composition, and technological traits. Int Dairy J 2022. [DOI: 10.1016/j.idairyj.2021.105221] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
6
|
Chen Y, Ma Y, Ji Q, Yang X, Feng X, Yao R, Cheng X, Li T, Wang Y, Wang Z. Intracellular Staphylococcus aureus Infection Decreases Milk Protein Synthesis by Preventing Amino Acid Uptake in Bovine Mammary Epithelial Cells. Front Vet Sci 2021; 8:756375. [PMID: 34869729 PMCID: PMC8636274 DOI: 10.3389/fvets.2021.756375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/22/2021] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is one of the main pathogens in cow mastitis, colonizing mammary tissues and being internalized into mammary epithelial cells, causing intracellular infection in the udder. Milk that is produced by cows that suffer from mastitis due to S. aureus is associated with decreased production and changes in protein composition. However, there is limited information on how mastitis-inducing bacteria affect raw milk, particularly with regard to protein content and protein composition. The main purpose of this work was to examine how S. aureus infection affects milk protein synthesis in bovine mammary epithelial cells (BMECs). BMECs were infected with S. aureus, and milk protein and amino acid levels were determined by ELISA after S. aureus invasion. The activity of mTORC1 signaling and the transcription factors NF-κB and STAT5 and the expression of the amino acid transporters SLC1A3 and SLC7A5 were measured by western blot or immunofluorescence and RT-qPCR. S. aureus was internalized by BMECs in vitro, and the internalized bacteria underwent intracellular proliferation. Eight hours after S. aureus invasion, milk proteins were downregulated, and the level of BMECs that absorbed Glu, Asp, and Leu from the culture medium and the exogenous amino acids induced β-casein synthesis declined. Further, the activity of mTORC1 signaling, NF-κB, and STAT5 was impaired, and SLC1A3 and SLC7A5 were downregulated. Eight hours of treatment with 100 nM rapamycin inhibited NF-κB and STAT5 activity, SLC1A3 and SLC7A5 expression, and milk protein synthesis in BMECs. Thus mTORC1 regulates the expression of SLC1A3 and SLC7A5 through NF-κB and STAT5. These findings constitute a model by which S. aureus infection suppresses milk protein synthesis by decreasing amino acids uptake in BMECs.
Collapse
Affiliation(s)
- Yuhao Chen
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China.,School of Life Sciences and Technology, Jining Normal University, Jining, China
| | - Yuze Ma
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Qiang Ji
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xiaoru Yang
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xue Feng
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Ruiyuan Yao
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Xiaoou Cheng
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Tingting Li
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Yanfeng Wang
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| | - Zhigang Wang
- State Key Laboratory of Reproductive Regulation & Breeding of Grassland Livestock, School of Life Sciences, Inner Mongolia University, Hohhot, China
| |
Collapse
|
7
|
Wu KY, Yang TX, Li QY. The effects of pH and NaCl concentration on the structure of β-casein from buffalo milk. Food Sci Nutr 2021; 9:2436-2445. [PMID: 34026061 PMCID: PMC8121154 DOI: 10.1002/fsn3.2157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 01/07/2021] [Accepted: 01/09/2021] [Indexed: 11/07/2022] Open
Abstract
In the present study, we aimed to investigate the effects of pH and sodium chloride (NaCl) concentration on the structure of β-casein (β-CN) purified from buffalo milk using circular dichroism (CD), intrinsic tryptophan, and anilino-8-naphthalene sulfonate (ANS) fluorescence spectroscopy. We found that NaCl concentration played a critical role in the stability of the secondary structure of β-CN. The CD negative peak had a redshift as the NaCl concentration was increased and accompanied by a decrease of β-sheet content and an increase of α-helix content. ANS fluorescence spectroscopy also indicated that higher NaCl concentration and lower pH significantly affected the tertiary structure of β-CN. Dynamic light scattering (DLS) results showed that the particle size of buffalo β-CN had a blueshift, and then a redshift within the pH range of 5.0-7.5, and it showed a redshift when the NaCl concentration was increased.
Collapse
Affiliation(s)
- Kong Yang Wu
- College of Life ScienceLuoyang Normal UniversityLuoyangChina
| | - Tong Xiang Yang
- College of Food and BioengineeringHenan University of Science and TechnologyLuoyangChina
| | - Quan Yang Li
- College of Light Industry and Food EngineeringGuangxi UniversityNanningChina
| |
Collapse
|
8
|
Liu C, Jiang TT, Yuan ZX, Lu Y. Self-Assembled Casein Nanoparticles Loading Triptolide for the Enhancement of Oral Bioavailability. Nat Prod Commun 2020. [DOI: 10.1177/1934578x20948352] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Triptolide (TP), a broad-spectrum antitumor drug, has very poor solubility and oral bioavailability, which limits its clinical use. Compared with conventional formulations of TP, a casein (Cas)-based drug delivery system has been reported to have significant advantages for the improvement of solubility and bioavailability of insoluble drugs. In this paper, we report the successful preparation of TP-loaded Cas nanoparticles (TP-Cas) using the self-assembly characteristics of Cas in water and the optimization of the formulation by evaluation of entrapment efficiency (EE) and loading efficiency (LE). Dynamic light scattering, transmission electron microscopy, Fourier-transform infrared spectrometry, X-ray diffractometry (XRD), and differential scanning calorimetry (DSC) was adopted to characterize the TP-Cas. Results showed that the obtained TP-Cas were approximately spherical with a particle size of 128.7 ± 11.5 nm, EE of 72.7 ± 4.7 %, and LE of 8.0% ± 0.5%. Furthermore, in vitro release behavior of TP-Cas in PBS (pH = 7.4) was also evaluated, showing a sustained-release profile. Additionally, an in vivo study in rats displayed that the mean plasma concentration of TP after oral administration of TP-Cas was significantly higher than that treated with TP oral suspension. The C max value for TP-Cas (8.0 ± 4.4 μg/mL) was significantly increased compared with the free TP (0.9 ± 0.3 μg/mL). Accordingly, the area under the curve (AUC0-8) of TP-Cas was 2.8 ± 0.8 mg/L·h, 4.3-fold higher than that of TP suspension (0.6 ± 0.1 mg/L·h). Therefore, it can be concluded that TP-Cas enhanced the absorption and improved oral bioavailability of TP. Taking the good oral safety of Cas into consideration, TP-Cas should be a more promising preparation of TP for clinical application.
Collapse
Affiliation(s)
- Chengxia Liu
- Department of Endodontics, Stomatological Hospital of Southern Medical University, Guangzhou, China
| | - Ting-ting Jiang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and Collaborative Innovation Center of Biotherapy, Sichuan University, Chengdu, China
| | - Zhi-xiang Yuan
- College of Pharmacy, Southwest Minzu University, Chengdu, China
| | - Yu Lu
- Department of Endodontics, Stomatological Hospital of Southern Medical University, Guangzhou, China
| |
Collapse
|
9
|
Casein nanoparticles as oral delivery carriers of mequindox for the improved bioavailability. Colloids Surf B Biointerfaces 2020; 195:111221. [PMID: 32652401 DOI: 10.1016/j.colsurfb.2020.111221] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 11/22/2022]
Abstract
Mequindox (Meq) is a promising broad-spectrum antibacterial agent, but the clinical application of Meq has been hampered by its low oral bioavailability. Casein (Cas) can bind to a variety of poorly water-soluble drugs to improve their water solubility through a micellar solubilization mechanism. Here, a low-cost and convenient method was introduced to prepare mequindox-loaded casein nanoparticles (Meq-Cas). Meq-Cas was characterized by several methods including differential scanning calorimetry (DSC), X-ray diffraction (XRD), and fourier transform infrared (FTIR) to illuminate the mutual effect between the drug and carriers. Meq-Cas presented nearly spherical nanoparticles with smooth surfaces and its mean particle size was lower than untreated Cas. Meq-Cas showed a nearly complete release of Meq, which displayed a biphasic drug release pattern in both phosphate-buffered solution (PBS) and simulated gastric fluid (SGF). The relative oral bioavailability of Meq-Cas was found to be about 1.20 times higher than that of the animals treated with Meq suspension (control). These results suggest that Cas is a good candidate to load in Meq for pharmaceutical purposes.
Collapse
|
10
|
Ren L, Wu Z, Zhang Y, Li K, Yuan J, Li X, Yang A, Tong P, Chen H. Polyphenol-oxidase-catalyzed cross-linking of Ara h 2: reaction sites and effect on structure and allergenicity. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:308-314. [PMID: 31525267 DOI: 10.1002/jsfa.10040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 08/25/2019] [Accepted: 09/11/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Peanut is among the most common of food allergies, and one of its allergens is Ara h 2. A previous study revealed that this allergen was recognized by serum immunoglobulin E (IgE) in over 90% of a peanut-allergic patient population. Enzymatic cross-linking is a popular processing method used to tailor food functionality, such as antigenicity. RESULT The cross-linking reactions of Ara h 2 were catalyzed by polyphenol oxidase (PPO), and the relevant reaction sites were identified using mass spectrometry and StavroX software. Two pairs of intramolecular cross-linking peptides and two intermolecular cross-linking peptides were found. Intramolecular cross-linking was speculated to occur between ARG131 (amino acids 116-131) and TYR65 (amino acids 63-80) and between TYR60 (amino acids 56-62) and ARG92 (amino acids 92-102); the intermolecular cross-linking sites were ARG31 with TYR84 or TYR89 and TYR65 or TYR72 with ARG92 or ARG102 . Three out of four cross-linking peptides were found in α-helices, and destruction of this secondary structure resulted in a loose tertiary structure. Although seven linear allergen epitopes were involved in cross-linking, the IgE binding capacity of protein changed slightly, while its sensitization potential decreased in mouse model. CONCLUSION Exploring the structural change of Ara h 2 after cross-linking is beneficial in further understanding the influence of structure on sensitization. This result indicated the future possibility of precision processing on structure of proteins to improve their properties. © 2019 Society of Chemical Industry.
Collapse
Affiliation(s)
- Linmei Ren
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Environment and Chemical Engineering, Nanchang University, Nanchang, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Food Science and Technology, Nanchang University, Nanchang, China
| | - Kun Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Hubei Provincial Key Lab for Quality and Safety of Traditional Chinese Medicine Health Food Jing Brand Bio-medicine Co Ltd, Huangshi, China
| | - Juanli Yuan
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
| |
Collapse
|
11
|
Boire A, Renard D, Bouchoux A, Pezennec S, Croguennec T, Lechevalier V, Le Floch-Fouéré C, Bouhallab S, Menut P. Soft-Matter Approaches for Controlling Food Protein Interactions and Assembly. Annu Rev Food Sci Technol 2019; 10:521-539. [PMID: 30633568 DOI: 10.1146/annurev-food-032818-121907] [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] [Indexed: 11/09/2022]
Abstract
Animal- and plant-based proteins are present in a wide variety of raw and processed foods. They play an important role in determining the final structure of food matrices. Food proteins are diverse in terms of their biological origin, molecular structure, and supramolecular assembly. This diversity has led to segmented experimental studies that typically focus on one or two proteins but hinder a more general understanding of food protein structuring as a whole. In this review, we propose a unified view of how soft-matter physics can be used to control food protein assembly. We discuss physical models from polymer and colloidal science that best describe and predict the phase behavior of proteins. We explore the occurrence of phase transitions along two axes: increasing protein concentration and increasing molecular attraction. This review provides new perspectives on the link between the interactions, phase transitions, and assembly of proteins that can help in designing new food products and innovative food processing operations.
Collapse
Affiliation(s)
- Adeline Boire
- Biopolymères Interactions Assemblages, INRA UR1268, F-44300 Nantes, France;
| | - Denis Renard
- Biopolymères Interactions Assemblages, INRA UR1268, F-44300 Nantes, France;
| | - Antoine Bouchoux
- LISBP, Université de Toulouse, CNRS, INRA, INSA, F-31077 Toulouse, France
| | | | | | | | | | - Saïd Bouhallab
- STLO, INRA UMR1253, Agrocampus Ouest, F-35042 Rennes, France
| | - Paul Menut
- Montpellier SupAgro, 34060 Montpellier, France; .,Ingénierie Procédés Aliments, AgroParisTech, INRA, Université Paris-Saclay, 91300 Massy, France
| |
Collapse
|
12
|
β-Casein micelles for oral delivery of SN-38 and elacridar to overcome BCRP-mediated multidrug resistance in gastric cancer. Eur J Pharm Biopharm 2018; 133:240-249. [DOI: 10.1016/j.ejpb.2018.10.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 11/22/2022]
|
13
|
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
|
14
|
β-casein nanovehicles for oral delivery of chemotherapeutic Drug combinations overcoming P-glycoprotein-mediated multidrug resistance in human gastric cancer cells. Oncotarget 2018; 7:23322-34. [PMID: 26989076 PMCID: PMC5029629 DOI: 10.18632/oncotarget.8019] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/21/2016] [Indexed: 02/02/2023] Open
Abstract
Multidrug resistance (MDR) is a primary obstacle to curative cancer therapy. We have previously demonstrated that β-casein (β-CN) micelles (β-CM) can serve as nanovehicles for oral delivery and target-activated release of hydrophobic drugs in the stomach. Herein we introduce a novel nanosystem based on β-CM, to orally deliver a synergistic combination of a chemotherapeutic drug (Paclitaxel) and a P-glycoprotein-specific transport inhibitor (Tariquidar) individually encapsulated within β-CM, for overcoming MDR in gastric cancer. Light microscopy, dynamic light scattering and zeta potential analyses revealed solubilization of these drugs by β-CN, suppressing drug crystallization. Spectrophotometry demonstrated high loading capacity and good encapsulation efficiency, whereas spectrofluorometry revealed high affinity of these drugs to β-CN. In vitro cytotoxicity assays exhibited remarkable synergistic efficacy against human MDR gastric carcinoma cells with P-glycoprotein overexpression. Oral delivery of β-CN - based nanovehicles carrying synergistic drug combinations to the stomach constitutes a novel efficacious therapeutic system that may overcome MDR in gastric cancer.
Collapse
|
15
|
Liu F, Gao J, Li X, Chen H. Molecular modeling and conformational IgG epitope mapping on bovine β-casein. Eur Food Res Technol 2016. [DOI: 10.1007/s00217-016-2689-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
16
|
Milk Protein Polymer and Its Application in Environmentally Safe Adhesives. Polymers (Basel) 2016; 8:polym8090324. [PMID: 30974597 PMCID: PMC6432148 DOI: 10.3390/polym8090324] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 08/22/2016] [Accepted: 08/23/2016] [Indexed: 11/17/2022] Open
Abstract
Milk proteins (caseins and whey proteins) are important protein sources for human nutrition; in addition, they possess important natural polymers. These protein molecules can be modified by physical, chemical, and/or enzymatic means. Casein is one of the oldest natural polymers, used for adhesives, dating back to thousands years ago. Research on milk-protein-based adhesives is still ongoing. This article deals with the chemistry and structure of milk protein polymers, and examples of uses in environmentally-safe adhesives. These are promising routes in the exploration of the broad application of milk proteins.
Collapse
|
17
|
Abstract
INTRODUCTION Most anticancer drugs have poor aqueous solubility and low permeability across the gastrointestinal tract. Furthermore, extensive efflux by P-glycoproteins (P-gp) in the small intestine also limits the efficient delivery of anticancer drugs via oral route. Area covered: This review explores the prodrug strategy for oral delivery of anticancer drugs. Different categories of oral anticancer prodrugs along with recent clinical studies have been comprehensively reviewed here. Furthermore, novel anticancer prodrugs such as polymer-prodrugs and lipid-prodrugs have been discussed in detail. Finally, various nanocarrier-based approaches employed for oral delivery of anticancer prodrugs have also been discussed. Expert opinion: Premature degradation of anticancer prodrugs in the gastrointestinal tract could lead to variable pharmacokinetics and undesired toxicity. Despite their increased aqueous solubility, the oral bioavailability of several anticancer prodrugs are limited by their poor permeability across the gastrointestinal tract. These limitations can be overcome by the use of functional excipients (polymers, lipids, amino acids/dipeptides), which are specifically absorbed via transporters and receptor-mediated endocytosis. Oral delivery of anticancer prodrugs using nanocarrier-based drug delivery system is a recent development; however it should be justified based on the comparative advantages of encapsulating prodrug in a nanocarrier versus the use of anticancer prodrug molecule itself.
Collapse
Affiliation(s)
- Amit K Jain
- a Department of Chemical Engineering , Texas Tech University , Lubbock , TX , USA
| | - Sanyog Jain
- b Centre for Pharmaceutical Nanotechnology, Department of Pharmaceutics , National Institute of Pharmaceutical Education and Research (NIPER) , Mohali , Punjab , India
| |
Collapse
|
18
|
Moeiniafshari AA, Zarrabi A, Bordbar AK. Exploring the interaction of naringenin with bovine beta-casein nanoparticles using spectroscopy. Food Hydrocoll 2015. [DOI: 10.1016/j.foodhyd.2015.04.036] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
19
|
Beveridge R, Phillips AS, Denbigh L, Saleem HM, MacPhee CE, Barran PE. Relating gas phase to solution conformations: Lessons from disordered proteins. Proteomics 2015; 15:2872-83. [PMID: 25920945 PMCID: PMC4744708 DOI: 10.1002/pmic.201400605] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/18/2015] [Accepted: 04/24/2015] [Indexed: 01/23/2023]
Abstract
In recent years both mass spectrometry (MS) and ion mobility mass spectrometry (IM‐MS) have been developed as techniques with which to study proteins that lack a fixed tertiary structure but may contain regions that form secondary structure elements transiently, namely intrinsically disordered proteins (IDPs). IM‐MS is a suitable method for the study of IDPs which provides an insight to conformations that are present in solution, potentially enabling the analysis of lowly populated structural forms. Here, we describe the IM‐MS data of two IDPs; α‐Synuclein (α‐Syn) which is implicated in Parkinson's disease, and Apolipoprotein C‐II (ApoC‐II) which is involved in cardiovascular diseases. We report an apparent discrepancy in the way that ApoC‐II behaves in the gas phase. While most IDPs, including α‐Syn, present in many charge states and a wide range of rotationally averaged collision cross sections (CCSs), ApoC‐II presents in just four charge states and a very narrow range of CCSs, independent of solution conditions. Here, we compare MS and IM‐MS data of both proteins, and rationalise the differences between the proteins in terms of different ionisation processes which they may adhere to.
Collapse
Affiliation(s)
- Rebecca Beveridge
- The Michael Barber Centre for Collaborative Mass Spectrometry, The School of Chemistry, Manchester Institute for Biotechnology, University of Manchester, Manchester, UK
| | - Ashley S Phillips
- The Michael Barber Centre for Collaborative Mass Spectrometry, The School of Chemistry, Manchester Institute for Biotechnology, University of Manchester, Manchester, UK
| | | | - Hassan M Saleem
- The Michael Barber Centre for Collaborative Mass Spectrometry, The School of Chemistry, Manchester Institute for Biotechnology, University of Manchester, Manchester, UK
| | - Cait E MacPhee
- School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
| | - Perdita E Barran
- The Michael Barber Centre for Collaborative Mass Spectrometry, The School of Chemistry, Manchester Institute for Biotechnology, University of Manchester, Manchester, UK
| |
Collapse
|
20
|
Fan Q, Ma J, Xu Q, Zhang J, Simion D, Carmen G, Guo C. Animal-derived natural products review: Focus on novel modifications and applications. Colloids Surf B Biointerfaces 2015; 128:181-190. [DOI: 10.1016/j.colsurfb.2015.02.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 02/14/2015] [Accepted: 02/16/2015] [Indexed: 10/23/2022]
|
21
|
Setter O, Livney YD. The effect of sugar stereochemistry on protein self-assembly: the case of β-casein micellization in different aldohexose solutions. Phys Chem Chem Phys 2015; 17:3599-606. [DOI: 10.1039/c4cp03686g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sugars promote self-assembly of amphiphilic proteins. The effectiveness of sugar stereoisomers correlates positively with their dynamic hydration number and negatively with their hydrophobic-to-hydrophilic molecular surface ratio.
Collapse
Affiliation(s)
- Ofer Setter
- Department of Biotechnology and Food Engineering
- Technion-Israel Institute of Technology
- Haifa
- Israel
| | - Yoav D. Livney
- Department of Biotechnology and Food Engineering
- Technion-Israel Institute of Technology
- Haifa
- Israel
- Russell Berrie Nanotechnology Institute
| |
Collapse
|
22
|
Beveridge R, Covill S, Pacholarz KJ, Kalapothakis JMD, MacPhee CE, Barran PE. A Mass-Spectrometry-Based Framework To Define the Extent of Disorder in Proteins. Anal Chem 2014; 86:10979-91. [DOI: 10.1021/ac5027435] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rebecca Beveridge
- Manchester
Institute of Biotechnology, Michael Barber Centre for Collaborative
Mass Spectrometry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| | - Sam Covill
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
| | - Kamila J. Pacholarz
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
| | - Jason M. D. Kalapothakis
- School
of Chemistry, University of Edinburgh, Joseph Black Building, West Mains
Road, Edinburgh EH9 3JJ, United Kingdom
- School
of Physics and Astronomy, University of Edinburgh, James Clerk
Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom
| | - Cait E. MacPhee
- School
of Physics and Astronomy, University of Edinburgh, James Clerk
Maxwell Building, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom
| | - Perdita E. Barran
- Manchester
Institute of Biotechnology, Michael Barber Centre for Collaborative
Mass Spectrometry, University of Manchester, 131 Princess Street, Manchester, M1 7DN, United Kingdom
| |
Collapse
|
23
|
Dallas DC, Weinborn V, de Moura Bell JMLN, Wang M, Parker EA, Guerrero A, Hettinga KA, Lebrilla CB, German JB, Barile D. Comprehensive peptidomic and glycomic evaluation reveals that sweet whey permeate from colostrum is a source of milk protein-derived peptides and oligosaccharides. Food Res Int 2014; 63:203-209. [PMID: 25284962 DOI: 10.1016/j.foodres.2014.03.021] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Whey permeate is a co-product obtained when cheese whey is passed through an ultrafiltration membrane to concentrate whey proteins. Whey proteins are retained by the membrane, whereas the low-molecular weight compounds such as lactose, salts, oligosaccharides and peptides pass through the membrane yielding whey permeate. Research shows that bovine milk from healthy cows contains hundreds of naturally occurring peptides - many of which are homologous with known antimicrobial and immunomodulatory peptides - and nearly 50 oligosaccharide compositions (not including structural isomers). As these endogenous peptides and oligosaccharides have low-molecular weight and whey permeate is currently an under-utilized product stream of the dairy industry, we hypothesized that whey permeate may serve as an inexpensive source of naturally occurring functional peptides and oligosaccharides. Laboratory fractionation of endogenous peptides and oligosaccharides from bovine colostrum sweet whey was expanded to pilot-scale. The membrane fractionation methodology used was similar to the methods commonly used industrially to produce whey protein concentrate and whey permeate. Pilot-scale fractionation was compared to laboratory-scale fractionation with regard to the identified peptides and oligosaccharide compositions. Results were interpreted on the basis of whether industrial whey permeate could eventually serve as a source of functional peptides and oligosaccharides. The majority (96%) of peptide sequences and the majority (96%) of oligosaccharide compositions found in the laboratory-scale process were mirrored in the pilot-scale process. Moreover, the pilot-scale process recovered an additional 33 peptides and 1 oligosaccharide not identified from the laboratory-scale extraction. Both laboratory- and pilot-scale processes yielded peptides deriving primarily from the protein β-casein. The similarity of the laboratory-and pilot-scale's resulting peptide and oligosaccharide profiles demonstrates that whey permeate can serve as an industrial-scale source of bovine milk peptides and oligosaccharides.
Collapse
Affiliation(s)
- David C Dallas
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States ; Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Valerie Weinborn
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Juliana M L N de Moura Bell
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Meng Wang
- Dairy Science and Technology Group, Food Quality and Design Group, Wageningen University, Bomenweg 2, Wageningen 6703HD, The Netherlands
| | - Evan A Parker
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Andres Guerrero
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Kasper A Hettinga
- Dairy Science and Technology Group, Food Quality and Design Group, Wageningen University, Bomenweg 2, Wageningen 6703HD, The Netherlands
| | - Carlito B Lebrilla
- Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States ; Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| | - J Bruce German
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States ; Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| | - Daniela Barile
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States ; Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
| |
Collapse
|
24
|
Zhang J, Liu Y, Liu X, Li Y, Yin X, Subirade M, Zhou P, Liang L. The folic acid/β-casein complex: Characteristics and physicochemical implications. Food Res Int 2014. [DOI: 10.1016/j.foodres.2014.01.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
25
|
Johansson M, Åkerstedt M, Li S, Zamaratskaia G, Sternesjö Lundh Å. Casein breakdown in bovine milk by a field strain of Staphylococcus aureus. J Food Prot 2013; 76:1638-42. [PMID: 23992512 DOI: 10.4315/0362-028x.jfp-13-112] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objectives of this study were to establish the proteolytic effects of Staphylococcus aureus during mastitis on economically important milk proteins. Concentrations of milk proteins were determined by capillary electrophoresis in an experimental model using a field strain of S. aureus. The pathogen was inoculated into bacteria-free control milk to imitate proteolysis caused by the pathogen in the mammary gland between milkings. Milk content of caseins (CN) α(S1), α(S2), κ, β(A1), and β(A2) and whey proteins α-lactalbumin and β-lactoglobulin were analyzed initially and after 6 h of incubation. After 6 h, the overall CN content was significantly reduced (21%) in milk inoculated with S. aureus compared with the bacteria-free control milk. S. aureus significantly lowered concentration of α(S1)-CN (2.5%), β(A1)-CN (3%), and β(A2)-CN (5%). S. aureus also hydrolyzed κ-CN into para-κ-CN, with significant reduction of κ-CN (7.4%) as a consequence.
Collapse
Affiliation(s)
- Monika Johansson
- Department of Food Science, Uppsala BioCenter, Swedish University of Agricultural Sciences, SE-750 07 Uppsala, Sweden.
| | | | | | | | | |
Collapse
|
26
|
Henriquez DR, Zhao C, Zheng H, Arbildua JJ, Acevedo ML, Roth MJ, Leon O. Crosslinking and mass spectrometry suggest that the isolated NTD domain dimer of Moloney murine leukemia virus integrase adopts a parallel arrangement in solution. BMC STRUCTURAL BIOLOGY 2013; 13:14. [PMID: 23844665 PMCID: PMC3750625 DOI: 10.1186/1472-6807-13-14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 07/08/2013] [Indexed: 12/20/2022]
Abstract
Background Retroviral integrases (INs) catalyze the integration of viral DNA in the chromosomal DNA of the infected cell. This reaction requires the multimerization of IN to coordinate a nucleophilic attack of the 3’ ends of viral DNA at two staggered phosphodiester bonds on the recipient DNA. Several models indicate that a tetramer of IN would be required for two-end concerted integration. Complementation assays have shown that the N-terminal domain (NTD) of integrase is essential for concerted integration, contributing to the formation of a multimer through protein-protein interaction. The isolated NTD of Mo-MLV integrase behave as a dimer in solution however the structure of the dimer in solution is not known. Results In this work, crosslinking and mass spectrometry were used to identify regions involved in the dimerization of the isolated Mo-MLV NTD. The distances between the crosslinked lysines within the monomer are in agreement with the structure of the NTD monomer found in 3NNQ. The intermolecular crosslinked peptides corresponding to Lys 20-Lys 31, Lys 24-Lys 24 and Lys 68-Lys 88 were identified. The 3D coordinates of 3NNQ were used to derive a theoretical structure of the NTD dimer with the suite 3D-Dock, based on shape and electrostatics complementarity, and filtered with the distance restraints determined in the crosslinking experiments. Conclusions The crosslinking results are consistent with the monomeric structure of NTD in 3NNQ, but for the dimer, in our model both polypeptides are oriented in parallel with each other and the contacting areas between the monomers would involve the interactions between helices 1 and helices 3 and 4.
Collapse
Affiliation(s)
- Daniel R Henriquez
- Programa de Virologia ICBM, Facultad de Medicina, Universidad de Chile, Independencia 1027, Santiago, Chile
| | | | | | | | | | | | | |
Collapse
|
27
|
Dallas DC, Guerrero A, Khaldi N, Castillo PA, Martin WF, Smilowitz JT, Bevins CL, Barile D, German JB, Lebrilla CB. Extensive in vivo human milk peptidomics reveals specific proteolysis yielding protective antimicrobial peptides. J Proteome Res 2013; 12:2295-304. [PMID: 23586814 DOI: 10.1021/pr400212z] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Milk is traditionally considered an ideal source of the basic elemental nutrients required by infants. More detailed examination is revealing that milk represents a more functional ensemble of components with benefits to both infants and mothers. A comprehensive peptidomics method was developed and used to analyze human milk yielding an extensive array of protein products present in the fluid. Over 300 milk peptides were identified originating from major and many minor protein components of milk. As expected, the majority of peptides derived from β-casein, however no peptide fragments from the major milk proteins lactoferrin, α-lactalbumin, and secretory immunoglobulin A were identified. Proteolysis in the mammary gland is selective-released peptides were drawn only from specific proteins and typically from only select parts of the parent sequence. A large number of the peptides showed significant sequence overlap with peptides with known antimicrobial or immunomodulatory functions. Antibacterial assays showed the milk peptide mixtures inhibited the growth of Escherichia coli and Staphylococcus aureus . The predigestion of milk proteins and the consequent release of antibacterial peptides may provide a selective advantage through evolution by protecting both the mother's mammary gland and her nursing offspring from infection.
Collapse
Affiliation(s)
- David C Dallas
- Department of Food Science and Technology, University of California at Davis, One Shields Avenue, Davis, California 95616, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Konnova TA, Faizullin DA, Haertle T, Zuev YF. β-casein micelle formation in water-ethanol solutions. DOKL BIOCHEM BIOPHYS 2013; 448:36-9. [DOI: 10.1134/s1607672913010092] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Indexed: 11/23/2022]
|
29
|
Ghahghaei A, Karfarma A. The effect of Arg and Gly on the chaperone propensity of bovine milk protein, β-casein, in preventing protein aggregation. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s13594-012-0103-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
30
|
Sharifizadeh A, Saboury AA, Moosavi-Movahedi AA, Salami M, Yousefi R. A new aspect to chaperone-like activity of bovine β-casein by protein–protein interactions study. Int J Biol Macromol 2012; 51:901-7. [DOI: 10.1016/j.ijbiomac.2012.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/31/2012] [Accepted: 08/01/2012] [Indexed: 11/29/2022]
|
31
|
Cassone M, Gagne AL, Spruce LA, Seeholzer SH, Sebert ME. The HtrA protease from Streptococcus pneumoniae digests both denatured proteins and the competence-stimulating peptide. J Biol Chem 2012; 287:38449-59. [PMID: 23012372 DOI: 10.1074/jbc.m112.391482] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The HtrA protease of Streptococcus pneumoniae functions both in a general stress response role and as an error sensor that specifically represses genetic competence when the overall level of biosynthetic errors in cellular proteins is low. However, the mechanism through which HtrA inhibits development of competence has been unknown. We found that HtrA digested the pneumococcal competence-stimulating peptide (CSP) and constituted the primary extracytoplasmic CSP-degrading activity in cultures of S. pneumoniae. Mass spectrometry demonstrated that cleavage predominantly followed residue Phe-8 of the CSP-1 isoform of the peptide within its central hydrophobic patch, and in competition assays, both CSP-1 and CSP-2 interacted with HtrA with similar efficiencies. More generally, analysis of β-casein digestion and of digestion within HtrA itself revealed a preference for substrates with non-polar residues at the P1 site. Consistent with a specificity for exposed hydrophobic residues, competition from native BSA only weakly inhibited digestion of CSP, but denaturation converted BSA into a strong competitive inhibitor of such proteolysis. Together these findings support a model in which digestion of CSP by HtrA is reduced in the presence of other unfolded proteins that serve as alternative targets for degradation. Such competition may provide a mechanism by which HtrA functions in a quality control capacity to monitor the frequency of biosynthetic errors that result in protein misfolding.
Collapse
Affiliation(s)
- Marco Cassone
- Division of Infectious Diseases, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | |
Collapse
|
32
|
Bernard H, Ah-Leung S, Tilleul S, Drumare MF, Paty E, Bidat E, Wal JM, Hazebrouck S. Specificity of IgE antibodies from patients allergic to goat's milk and tolerant to cow's milk determined with plasmin-derived peptides of bovine and caprine β-caseins. Mol Nutr Food Res 2012; 56:1532-40. [DOI: 10.1002/mnfr.201200229] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/09/2012] [Accepted: 07/10/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Hervé Bernard
- INRA, UR 496; Unité d'Immuno-Allergie Alimentaire; CEA/iBiTeC-S/SPI; CEA de Saclay; Gif-sur-Yvette France
| | - Sandrine Ah-Leung
- INRA, UR 496; Unité d'Immuno-Allergie Alimentaire; CEA/iBiTeC-S/SPI; CEA de Saclay; Gif-sur-Yvette France
| | - Sylvain Tilleul
- INRA, UR 496; Unité d'Immuno-Allergie Alimentaire; CEA/iBiTeC-S/SPI; CEA de Saclay; Gif-sur-Yvette France
| | - Marie-Françoise Drumare
- INRA, UR 496; Unité d'Immuno-Allergie Alimentaire; CEA/iBiTeC-S/SPI; CEA de Saclay; Gif-sur-Yvette France
| | - Evelyne Paty
- Université Paris Descartes, Assistance Publique des Hôpitaux de Paris; Hôpital Necker Enfants Malades; Paris France
| | - Etienne Bidat
- Service de Pédiatrie; Assistance Publique des Hôpitaux de Paris; Hôpital Ambroise Paré; Boulogne France
| | - Jean-Michel Wal
- INRA, UR 496; Unité d'Immuno-Allergie Alimentaire; CEA/iBiTeC-S/SPI; CEA de Saclay; Gif-sur-Yvette France
| | - Stéphane Hazebrouck
- INRA, UR 496; Unité d'Immuno-Allergie Alimentaire; CEA/iBiTeC-S/SPI; CEA de Saclay; Gif-sur-Yvette France
| |
Collapse
|
33
|
Zakharchenko NL, Konnova TA, Gogoleva NE, Faizullin DA, Haertle T, Zuev YF. Chaperone-like activity of β-casein and thermal stability of alcohol dehydrogenase. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2012; 38:223-8. [DOI: 10.1134/s1068162012020136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
34
|
Shapira A, Davidson I, Avni N, Assaraf YG, Livney YD. β-Casein nanoparticle-based oral drug delivery system for potential treatment of gastric carcinoma: stability, target-activated release and cytotoxicity. Eur J Pharm Biopharm 2011; 80:298-305. [PMID: 22085654 DOI: 10.1016/j.ejpb.2011.10.022] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/27/2011] [Accepted: 10/31/2011] [Indexed: 11/24/2022]
Abstract
We studied a potential drug delivery system comprising the hydrophobic anticancer drug paclitaxel entrapped within β-casein (β-CN) nanoparticles and its cytotoxicity to human gastric carcinoma cells. Paclitaxel was entrapped by stirring its dimethyl sulfoxide (DMSO) solution into PBS containing β-CN. Cryo-TEM analysis revealed drug nanocrystals, the growth of which was blocked by β-CN. Entrapment efficiency was nearly 100%, and the nanovehicles formed were colloidally stable. Following encapsulation and simulated digestion with pepsin (2 hours at pH=2, 37 °C), paclitaxel retained its cytotoxic activity to human N-87 gastric cancer cells; the IC(50) value (32.5 ± 6.2 nM) was similar to that of non-encapsulated paclitaxel (25.4 ± 2.6 nM). Without prior simulated gastric digestion, β-CN-paclitaxel nanoparticles were non-cytotoxic, suggesting the lack of untoward toxicity to bucal and esophageal epithelia. We conclude that β-CN shows promise to be useful for target-activated oral delivery of hydrophobic chemotherapeutics in the treatment of gastric carcinoma, one of the leading causes of cancer mortality worldwide.
Collapse
Affiliation(s)
- Alina Shapira
- Russell Berrie Nanotechnology Institute, Technion, Israel Institute of Technology, Haifa, Israel
| | | | | | | | | |
Collapse
|
35
|
Antoniou A, Herlem G, André C, Guillaume Y, Gharbi T. Simple method for detection of extremely diluted anti beta-casein antibodies from glass bead based receptors. Talanta 2011; 84:632-7. [DOI: 10.1016/j.talanta.2011.01.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 01/09/2011] [Accepted: 01/16/2011] [Indexed: 10/18/2022]
|
36
|
Thachepan S, Li M, Mann S. Mesoscale crystallization of calcium phosphate nanostructures in protein (casein) micelles. NANOSCALE 2010; 2:2400-2405. [PMID: 21080570 DOI: 10.1039/c0nr00158a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Aqueous micelles of the multi-protein calcium phosphate complex, casein, were treated at 60°C and pH 7 over several months. Although partial dissociation of the micelles into 12 nm sized amorphous calcium phosphate (ACP)/protein nanoparticles occurred within a period of 14 days, crystallization of the ACP nanoclusters into bundles of hydroxyapatite (HAP) nanofilaments was not observed until after 12 weeks. The HAP nanofilaments were formed specifically within the partially disrupted protein micelles suggesting a micelle-mediated pathway of mesoscale crystallization. Similar experiments using ACP-containing synthetic micelles prepared from ß-casein protein alone indicated that co-aligned bundles of HAP nanofilaments were produced within the protein micelle interior after 24 hours at temperatures as low as 35°C. The presence of Mg²(+) ions in the casein micelles, as well as a possible synergistic effect associated with the multi-protein nature of the native aggregates, could account for the marked inhibition in mesoscale crystallization observed in the casein micelles compared with the single-component b-casein constructs.
Collapse
Affiliation(s)
- Surachai Thachepan
- Centre for Organized Matter Chemistry, School of Chemistry, University of Bristol, Bristol, UK
| | | | | |
Collapse
|
37
|
Beta-casein Nanoparticles as an Oral Delivery System for Chemotherapeutic Drugs: Impact of Drug Structure and Properties on Co-assembly. Pharm Res 2010; 27:2175-86. [DOI: 10.1007/s11095-010-0222-7] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2010] [Accepted: 07/13/2010] [Indexed: 10/19/2022]
|
38
|
Shapira A, Markman G, Assaraf YG, Livney YD. β-casein–based nanovehicles for oral delivery of chemotherapeutic drugs: drug-protein interactions and mitoxantrone loading capacity. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2010; 6:547-55. [DOI: 10.1016/j.nano.2010.01.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 12/27/2009] [Accepted: 01/19/2010] [Indexed: 10/19/2022]
|
39
|
Espino-Díaz M, De Jesús Ornelas-Paz J, Martínez-Téllez MA, Santillán C, Barbosa-Cánovas GV, Zamudio-Flores PB, Olivas GI. Development and Characterization of Edible Films Based on Mucilage of Opuntia ficus-indica (L.). J Food Sci 2010; 75:E347-52. [DOI: 10.1111/j.1750-3841.2010.01661.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
40
|
Shapira A, Assaraf YG, Livney YD. Beta-casein nanovehicles for oral delivery of chemotherapeutic drugs. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2010; 6:119-26. [DOI: 10.1016/j.nano.2009.06.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2009] [Revised: 05/17/2009] [Accepted: 06/01/2009] [Indexed: 11/26/2022]
|
41
|
Day JPR, Pudney PDA, Bain CD. Ellipsometric study of the displacement of milk proteins from the oil–water interface by the non-ionic surfactant C10E8. Phys Chem Chem Phys 2010; 12:4590-9. [DOI: 10.1039/b921887d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
42
|
Yousefi R, Shchutskaya YY, Zimny J, Gaudin JC, Moosavi-Movahedi AA, Muronetz VI, Zuev YF, Chobert JM, Haertlé T. Chaperone-like activities of different molecular forms of beta-casein. Importance of polarity of N-terminal hydrophilic domain. Biopolymers 2009; 91:623-32. [PMID: 19322774 DOI: 10.1002/bip.21190] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
As a member of intrinsically unstructured protein family, beta-casein (beta-CN) contains relatively high amount of prolyl residues, adopts noncompact and flexible structure and exhibits chaperone-like activity in vitro. Like many chaperones, native beta-CN does not contain cysteinyl residues and exhibits strong tendencies for self-association. The chaperone-like activities of three recombinant beta-CNs wild type (WT) beta-CN, C4 beta-CN (with cysteinyl residue in position 4) and C208 beta-CN (with cysteinyl residue in position 208), expressed and purified from E. coli, which, consequently, lack the phosphorylated residues, were examined and compared with that of native beta-CN using insulin and alcohol dehydrogenase as target/substrate proteins. The dimers (beta-CND) of C4-beta-CN and C208 beta-CN were also studied and their chaperone-like activities were compared with those of their monomeric forms. Lacking phosphorylation, WT beta-CN, C208 beta-CN, C4 beta-CN and C4 beta-CND exhibited significantly lower chaperone-like activities than native beta-CN. Dimerization of C208 beta-CN with two distal hydrophilic domains considerably improved its chaperone-like activity in comparison with its monomeric form. The obtained results demonstrate the significant role played by the polar contributions of phosphorylated residues and N-terminal hydrophilic domain as important functional elements in enhancing the chaperone-like activity of native beta-CN. (c) 2009 Wiley Periodicals, Inc. Biopolymers 91: 623-632, 2009.This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com.
Collapse
Affiliation(s)
- Reza Yousefi
- Biopolymères Interactions Assemblages, INRA, équipe Fonctions et Interactions des Protéines Laitières, Nantes Cedex 3, France
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Marchenko NI, Marchenkov VV, Kaĭsheva AL, Kashparov IA, Kotova NV, Kaliman PA, Semisotnov GV. Affinity chromatography of GroEL chaperonin based on denatured proteins: role of electrostatic interactions in regulation of GroEL affinity for protein substrates. BIOCHEMISTRY (MOSCOW) 2007; 71:1357-64. [PMID: 17223789 DOI: 10.1134/s000629790612011x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The chaperonin GroEL of the heat shock protein family from Escherichia coli cells can bind various polypeptides lacking rigid tertiary structure and thus prevent their nonspecific association and provide for acquisition of native conformation. In the present work we studied the interaction of GroEL with six denatured proteins (alpha-lactalbumin, ribonuclease A, egg lysozyme in the presence of dithiothreitol, pepsin, beta-casein, and apocytochrome c) possessing negative or positive total charge at neutral pH values and different in hydrophobicity (affinity for a hydrophobic probe ANS). To prevent the influence of nonspecific association of non-native proteins on their interaction with GroEL and make easier the recording of the complexing, the proteins were covalently attached to BrCN-activated Sepharose. At low ionic strength (lower than 60 mM), tight binding of the negatively charged denatured proteins with GroEL (which is also negatively charged) needed relatively low concentrations (approximately 10 mM) of bivalent cations Mg2+ or Ca2+. At the high ionic strength (approximately 600 mM), a tight complex was produced also in the absence of bivalent cations. In contrast, positively charged denatured proteins tightly interacted with GroEL irrespectively of the presence of bivalent cations and ionic strength of the solution (from 20 to 600 mM). These features of GroEL interaction with positively and negatively charged denatured proteins were confirmed by polarized fluorescence (fluorescence anisotropy). The findings suggest that the affinity of GroEL for denatured proteins can be determined by the balance of hydrophobic and electrostatic interactions.
Collapse
Affiliation(s)
- N Iu Marchenko
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | | | | | | | | | | | | |
Collapse
|
44
|
Dickinson E. Structure formation in casein-based gels, foams, and emulsions. Colloids Surf A Physicochem Eng Asp 2006. [DOI: 10.1016/j.colsurfa.2006.01.012] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
45
|
Portnaya I, Cogan U, Livney YD, Ramon O, Shimoni K, Rosenberg M, Danino D. Micellization of bovine beta-casein studied by isothermal titration microcalorimetry and cryogenic transmission electron microscopy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:5555-61. [PMID: 16848545 DOI: 10.1021/jf060119c] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The association behavior, critical micellization concentration (CMC), and enthalpy of demicellization (DeltaHdemic) of bovine beta-casein were studied, for the first time by isothermal titration calorimetry, in a pH 7.0 phosphate buffer with 0.1 ionic strength and in pure water. In the buffer solutions, the CMC decreased asymptotically from 0.15 to 0.006 mM as the temperature was raised from 16 to 45 degrees C. DeltaHdemic decreased with increasing temperature between 16 and 28 degrees C but increased from 28 to 45 degrees C. Thermodynamic analysis below 30 degrees C is consistent with the Kegeles shell model, which suggests a stepwise association process. At higher temperatures, this model exhibits limitations, and the micellization becomes much more cooperative. The CMC values in water, measured between 17 and 28 degrees C, decreased with increasing temperature and, expectedly, were higher than those found in the buffer solutions. beta-Casein micelles were visualized and characterized, for the first time in their hydrated state, using advanced digital-imaging cryogenic transmission electron microscopy. The images revealed small, oblate micelles, about approximately 13 nm in diameter. The micelles shape and dimensions remained nearly constant in the temperature range of 24-35 degrees C.
Collapse
Affiliation(s)
- Irina Portnaya
- Department of Biotechnology and Food Engineering and Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa, 32000 Israel
| | | | | | | | | | | | | |
Collapse
|
46
|
Abstract
Some recent advances in the colloid science of heterogeneous systems containing food biopolymer ingredients are reviewed. Understanding the instability processes controlling the shelf-life and rheology of food colloids requires a detailed knowledge of the factors affecting the nature of the interactions in emulsions and gels containing mixtures of protein + protein, protein + surfactant and protein + polysaccharide. Against this background, theoretical modelling and computer simulation are useful tools for predicting effects of system composition on stability mechanisms. Confocal microscopy combined with image analysis is providing new experimental insight into the microstructural origins of changes in macroscopic properties during processing and storage.
Collapse
Affiliation(s)
- Eric Dickinson
- Procter Department of Food Science, University of Leeds, Leeds, UKLS2 9JT
| |
Collapse
|
47
|
Gaucher SP, Hadi MZ, Young MM. Influence of crosslinker identity and position on gas-phase dissociation of Lys-Lys crosslinked peptides. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2006; 17:395-405. [PMID: 16443364 DOI: 10.1016/j.jasms.2005.11.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 11/11/2005] [Accepted: 11/21/2005] [Indexed: 05/06/2023]
Abstract
A systematic study of the dissociation patterns of crosslinked peptides analyzed by tandem mass spectrometry is reported. A series of 11-mer peptides was designed around either a polyalanine or polyglycine scaffold with arginine at the C terminus. One or two lysine residues were included at various locations within the peptides to effect inter- or intra-molecular crosslinking, respectively. Crosslinked species were generated with four commonly used amine-specific chemical crosslinking reagents: disuccinimidyl suberate (DSS), disuccinimidyl tartarate (DST), dithiobis(succinimidylpropionate) (DSP), and disuccinimidyl glutarate (DSG). The influence of precursor charge state, location of crosslink, and specific crosslinking reagent on the MS/MS dissociation pattern was examined. Observed trends in the dissociation patterns obtained for these species will allow for improvements to software used in the automated interpretation of crosslinked peptide MS/MS data.
Collapse
Affiliation(s)
- Sara P Gaucher
- Sandia National Laboratories, Livermore, California 94551-0969, USA.
| | | | | |
Collapse
|
48
|
Parkinson EL, Ettelaie R, Dickinson E. Using Self-Consistent-Field Theory to Understand Enhanced Steric Stabilization by Casein-Like Copolymers at Low Surface Coverage in Mixed Protein Layers. Biomacromolecules 2005; 6:3018-29. [PMID: 16283722 DOI: 10.1021/bm050329i] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a statistical mechanical approach to predicting the properties of mixed copolymer layers using the Scheutjens-Fleer self-consistent-field theory. Our model copolymers are based on the primary structures of the major bovine casein monomers, alpha(s1)-casein and beta-casein. Numerical calculations have been carried out to determine the polymer segment density profiles at an isolated hydrophobic surface and the interaction forces as a pair of polymer-coated surfaces is brought to close interlayer separation. For a copolymer model containing hydrophilic and hydrophobic segments, we show how the steric stabilizing capacity of a casein-like macromolecule at very low surface coverage is enhanced in the presence of a thin dense layer of shorter tethered amphiphilic chains. Using a more refined protein model, which also distinguishes between the charged and uncharged hydrophilic segments along the chain, we clearly demonstrate that the enhanced steric repulsion from beta-casein exceeds that from alpha(s1)-casein. These calculations explain how the replacement of just a few percent of beta-lactoglobulin by casein can inhibit the heat-induced thickening and flocculation behavior observed experimentally with some whey protein-stabilized oil-in-water emulsions.
Collapse
Affiliation(s)
- Emma L Parkinson
- Procter Department of Food Science, University of Leeds, Leeds LS2 9JT, UK
| | | | | |
Collapse
|