Adal, E, Sadeghpour, A, Connell, S orcid.org/0000-0003-2500-5724 et al. (3 more authors) (2017) Heteroprotein complex formation of bovine lactoferrin and pea protein isolate: A multiscale structural analysis. Biomacromolecules, 18 (2). pp. 625-635. ISSN 1525-7797
Abstract
Associative electrostatic interactions between two oppositely charged globular proteins, lactoferrin (LF) and pea protein isolate (PPI), the latter being a mixture of vicilin, legumin, and convicilin, was studied with a specific PPI/LF molar ratio at room temperature. Structural aspects of the electrostatic complexes probed at different length scales were investigated as a function of pH by means of different complementary techniques, namely, with dynamic light scattering, small-angle X-ray scattering (SAXS), turbidity measurements, and atomic force microscopy (AFM). Irrespective of the applied techniques, the results consistently displayed that complexation between LF and PPI did occur. In an optimum narrow range of pH 5.0–5.8, a viscous liquid phase of complex coacervate was obtained upon mild centrifugation of the turbid LF-PPI mixture with a maximum Rh, turbidity and the ζ-potential being close to zero observed at pH 5.4. In particular, the SAXS data demonstrated that the coacervates were densely assembled with a roughly spherical size distribution exhibiting a maximum extension of ∼80 nm at pH 5.4. Equally, AFM image analysis showed size distributions containing most frequent cluster sizes around 40–80 nm with spherical to elliptical shapes (axis aspect ratio ≤ 2) as well as less frequent elongated to chainlike structures. The most frequently observed compact complexes, we identify as mainly leading to LF-PPI coacervation, whereas for the less frequent chain-like aggregates, we hypothesize that additionally PPI-PPI facilitated complexes exist.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2017, American Chemical Society. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Biomacromolecules, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.biomac.6b01857. |
Keywords: | Lactoferrin; Pea protein; Complex coacervation; Small Angle X-ray scattering (SAXS); Atomic Force Microscopy (AFM) |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Molecular & Nanoscale Physics |
Depositing User: | Symplectic Publications |
Date Deposited: | 19 Jan 2017 10:20 |
Last Modified: | 13 Jan 2018 01:38 |
Published Version: | https://doi.org/10.1021/acs.biomac.6b01857 |
Status: | Published |
Publisher: | American Chemical Society |
Identification Number: | 10.1021/acs.biomac.6b01857 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:110783 |