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Chen C, Murray BS, Ettelaie R. Surface adsorption properties of peptides produced by non-optimum pH pepsinolysis of proteins: A combined experimental and self-consistent-field calculation study. J Colloid Interface Sci 2023; 652:405-417. [PMID: 37604052 DOI: 10.1016/j.jcis.2023.08.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 08/01/2023] [Accepted: 08/06/2023] [Indexed: 08/23/2023]
Abstract
HYPOTHESIS Partial hydrolysis of large molecular weight (Mw), highly aggregated plant proteins is frequently used to improve their solubility. However, if this hydrolysis is extensive, random or nonselective, it is unlikely to improve functional properties such as surface activity, emulsion, or foam-stabilising capacity. EXPERIMENTS AND SIMULATION Soy protein isolate (SPI) was hydrolysed by pepsin under optimal (pH 2.1) and non-optimal (pH 4.7) conditions. The surface activity and emulsion stabilising capacity of the resultant peptides were measured and compared. The colloidal interactions between a pair of emulsion droplets were modelled via Self-Consistent-Field Calculations (SCFC). FINDINGS Hydrolysis at pH 2.1 and 4.7 resulted in a considerable increase in measured surface activity compared to the native (non-hydrolysed) SPI, but the hydrolysate from pH 2.1 was not as good an emulsion stabiliser as the hydrolysate (particularly the fraction Mw > 10 kDa) at pH 4.7. Furthermore, peptide analysis of the latter suggested it was dominated by a fragment of one of the major soy proteins β-conglycinin, with Mw ≈ 25 kDa. SCFC calculations confirmed that interactions mediated by adsorbed layers of this peptide point to it being an excellent emulsion stabiliser.
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Affiliation(s)
- Cuizhen Chen
- Food Colloids & Bioprocessing Group, School of Food Science & Nutrition, University of Leeds, Leeds LS2 9JT, UK
| | - Brent S Murray
- Food Colloids & Bioprocessing Group, School of Food Science & Nutrition, University of Leeds, Leeds LS2 9JT, UK.
| | - Rammile Ettelaie
- Food Colloids & Bioprocessing Group, School of Food Science & Nutrition, University of Leeds, Leeds LS2 9JT, UK.
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Murray BS, Ettelaie R, Sarkar A, Mackie AR, Dickinson E. The perfect hydrocolloid stabilizer: Imagination versus reality. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2021.106696] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Dantas MDDA, Silva MDM, Silva ON, Franco OL, Fensterseifer ICM, Tenório HDA, Pereira HJV, Figueiredo IM, Santos JCC. Interactions of tetracyclines with milk allergenic protein (casein): a molecular and biological approach. J Biomol Struct Dyn 2019; 38:5389-5400. [PMID: 31814537 DOI: 10.1080/07391102.2019.1702587] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Tetracycline (TC), oxytetracycline (OTC), and chlortetracycline (CTC) interactions with the allergenic milk protein casein (CAS) were here evaluated simulating food conditions. The antibiotics assessed interact with CAS through static quenching and form non-fluorescent complexes. At 30 °C, the binding constant (Kb) varied from 0.05 to 1.23 × 106 M-1. Tetracycline interacts with CAS preferably through electrostatic forces, while oxytetracycline and chlortetracycline interactions occur by hydrogen bonds and van der Waals forces. The interaction process is spontaneous, and the magnitude of interaction based on Kb values, followed the order: TC < CTC < OTC. The distances between the donor (protein) and the receptors (TC, OTC, and CTC) were determined by Förster resonance energy transfer (FRET) and varied from 3.67 to 4.08 nm. Under natural feeding conditions, the citrate decreased the affinity between TC and CAS; a similar effect was observed for OTC in the presence of Ca(II), Fe(III) and lactose. Synchronized and three-dimensional (3D) fluorescence studies indicated alterations in the original protein conformation due to the interaction process, which may influence allergenic processes. In addition, complexation with CAS modulated the antimicrobial activity of CTC against S. aureus, demonstrated that the interaction process possibly alters the biological properties of antibiotics and the own protein, in the food conditions.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | | | - Osmar Nascimento Silva
- S-Inova Biotech, Post-Graduate Program in Biotechnology, Dom Bosco Catholic University, Campo Grande, Brazil
| | - Octavio Luiz Franco
- S-Inova Biotech, Post-Graduate Program in Biotechnology, Dom Bosco Catholic University, Campo Grande, Brazil
| | | | | | - Hugo Juarez V Pereira
- Institute of Chemistry and Biotechnology, Federal University of Alagoas, Maceió, Brazil
| | - Isis M Figueiredo
- Institute of Chemistry and Biotechnology, Federal University of Alagoas, Maceió, Brazil
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Ettelaie R, Murray BS, Liu S. On the Origin of Seemingly Nonsurface-Active Particles Partitioning between Phase-Separated Solutions of Incompatible Nonadsorbing Polymers and Their Adsorption at the Phase Boundary. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:9493-9503. [PMID: 31240936 DOI: 10.1021/acs.langmuir.9b00892] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have computed the free energy per unit area (i.e., interfacial tension) between a solid surface and two coexisting polymer solutions, where there is no specific interaction between the particles and either polymer, via self-consistent field calculations. Several different systems have been studied, including those where the two polymers differ in molecular weight (Mw) by a factor of ∼2 or where the polymers have the same Mw, but one set of chains is branched with the other linear. In the absence of any enthalpic contribution resulting from adsorption on the solid particle surface, the differences in the free energy per unit area resulting from the polymer-depleted regions around the particles in the two coexisting phases are found to be ∼1 μN m-1. Although this value may seem rather small, this difference is more than capable of inducing the partitioning of particles of 100 nm in size (or larger) into the phase with the lower interfacial free energy at the solid surface. By examining the density profile variation of the polymers close to the surface, we can also infer information about the wettability and contact angle (θ) of solid particles at the interface between the two coexisting phases. This leads to the conclusion that for all systems of this type, when the incompatibility between the two polymers is sufficiently large, θ will be close to 90°.
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Affiliation(s)
- Rammile Ettelaie
- Food Colloids & Bioprocessing Group, School of Food Science and Nutrition , University of Leeds , Woodhouse Lane , Leeds LS2 9JT , U.K
| | - Brent S Murray
- Food Colloids & Bioprocessing Group, School of Food Science and Nutrition , University of Leeds , Woodhouse Lane , Leeds LS2 9JT , U.K
| | - Shujie Liu
- Food Colloids & Bioprocessing Group, School of Food Science and Nutrition , University of Leeds , Woodhouse Lane , Leeds LS2 9JT , U.K
- School of Food Science and Biotechnology , Zhejiang Gongshang University , Hangzhou , Zhejiang 310018 , China
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Lishchuk SV, Ettelaie R, Annable T. On the structural polydispersity of random copolymers adsorbed at interfaces: comparison of surface and bulk distributions. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1292369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Sergey V. Lishchuk
- Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield, United Kingdom
| | - Rammile Ettelaie
- Food Colloids Group, School of Food Science and Nutrition, University of Leeds, Leeds, United Kingdom
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Ding R, Valicka E, Akhtar M, Ettelaie R. Insignificant impact of the presence of lactose impurity on formation and colloid stabilising properties of whey protein–maltodextrin conjugates prepared via Maillard reactions. FOOD STRUCTURE-NETHERLANDS 2017. [DOI: 10.1016/j.foostr.2017.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ettelaie R, Holmes M, Chen J, Farshchi A. Steric stabilising properties of hydrophobically modified starch: Amylose vs. amylopectin. Food Hydrocoll 2016. [DOI: 10.1016/j.foodhyd.2016.03.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Selection of downstream steps by analysis of protein surface property: A case study for recombinant human lactoferrin purification from milk of transgenic cow. Process Biochem 2015. [DOI: 10.1016/j.procbio.2015.05.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ettelaie R, Akinshina A. Colloidal interactions induced by overlap of mixed protein+polysaccharide interfacial layers. Food Hydrocoll 2014. [DOI: 10.1016/j.foodhyd.2014.01.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Ettelaie R, Dickinson E, Pugnaloni L. First-order phase transition during displacement of amphiphilic biomacromolecules from interfaces by surfactant molecules. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:464109. [PMID: 25347051 DOI: 10.1088/0953-8984/26/46/464109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The adsorption of surfactants onto a hydrophobic interface, already laden with a fixed number of amphiphilic macromolecules, is studied using the self consistent field calculation method of Scheutjens and Fleer. For biopolymers having unfavourable interactions with the surfactant molecules, the adsorption isotherms show an abrupt jump at a certain value of surfactant bulk concentration. Alternatively, the same behaviour is exhibited when the number of amphiphilic chains on the interface is decreased. We show that this sudden jump is associated with a first-order phase transition, by calculating the free energy values for the stable and the metastable states at both sides of the transition point. We also observe that the transition can occur for two approaching surfaces, from a high surfactant coverage phase to a low surfactant coverage one, at sufficiently close separation distances. The consequence of this finding for the steric colloidal interactions, induced by the overlap of two biopolymer + surfactant films, is explored. In particular, a significantly different interaction, in terms of its magnitude and range, is predicted for these two phases. We also consider the relevance of the current study to problems involving the competitive displacement of proteins by surfactants in food colloid systems.
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Affiliation(s)
- Rammile Ettelaie
- Food Colloids Group, School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK
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Ettelaie R, Zengin A, Lee H. Fragmented proteins as food emulsion stabilizers: A theoretical study. Biopolymers 2014; 101:945-58. [DOI: 10.1002/bip.22487] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 03/11/2014] [Accepted: 03/14/2014] [Indexed: 01/19/2023]
Affiliation(s)
- Rammile Ettelaie
- Food Colloids Group; School of Food Science and Nutrition, University of Leeds; Leeds LS2 9JT UK
| | - Adem Zengin
- Food Colloids Group; School of Food Science and Nutrition, University of Leeds; Leeds LS2 9JT UK
| | - Hazel Lee
- Food Colloids Group; School of Food Science and Nutrition, University of Leeds; Leeds LS2 9JT UK
- Food Innovation Department, Leatherhead Food Research; Randalls Road Leatherhead Surrey KT22 7RY UK
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