Leibniz Institute for Materials Engineering - IWT, Badgasteiner Straße 3, 28359 Bremen, Germany.
Hybrid Materials Interfaces Group, University of Bremen, Faculty of Production Engineering, Bremen Center for Computational Materials Science, Center for Environmental Research and Sustainable Technology (UFT), Am Fallturm 1, 28359 Bremen, Germany; Biomolecular and Materials Interface Research Group, Interdisciplinary Biomedical Research Centre, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, United Kingdom.
J Colloid Interface Sci. 2022 Dec 15;628(Pt A):72-81. doi: 10.1016/j.jcis.2022.07.132. Epub 2022 Jul 25.
We present combined experimental and modelling evidence that β-lactoglobulin proteins employed as stabilizers of oil/water emulsions undergo minor but significant conformational changes during premix membrane emulsification processes. Circular Dichroism spectroscopy and Molecular Dynamics simulations reveal that the native protein structure is preserved as a metastable state after adsorption at stress-free oil/water interfaces. However, the shear stress applied to the oil droplets during their fragmentation in narrow membrane pores causes a transition into a more stable, partially unfolded interfacial state. The protein's β-sheet content is reduced by up to 8% in a way that is largely independent of the pressure applied during emulsification, and is driven by an increase of contacts between the oil and hydrophobic residues at the expense of structural order within the protein core.
我们提出了实验和建模证据的综合，表明在预混膜乳化过程中，用作油/水乳液稳定剂的β-乳球蛋白发生了微小但显著的构象变化。圆二色光谱和分子动力学模拟表明，在无应力油/水界面吸附后，天然蛋白质结构保持为亚稳态。然而，在狭窄膜孔中对油滴施加的剪切应力会导致其过渡到更稳定的部分展开的界面状态。在乳化过程中施加的压力基本不影响蛋白质的β-折叠含量降低了 8%，这主要是由于油与疏水性残基之间的接触增加，而蛋白质核心的结构有序性降低所致。
