Amara Chedia Ben, Degraeve Pascal, Oulahal Nadia, Gharsallaoui Adem
Univ Lyon, Université Lyon 1, ISARA Lyon, Laboratoire BioDyMIA (Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires), Equipe Mixte d'Accueil, n°3733, IUT Lyon 1, technopole Alimentec, rue Henri de Boissieu, F-01000 Bourg en Bresse, France.
Univ Lyon, Université Lyon 1, ISARA Lyon, Laboratoire BioDyMIA (Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires), Equipe Mixte d'Accueil, n°3733, IUT Lyon 1, technopole Alimentec, rue Henri de Boissieu, F-01000 Bourg en Bresse, France.
Food Chem. 2017 Dec 1;236:127-133. doi: 10.1016/j.foodchem.2017.03.124. Epub 2017 Mar 23.
In order to understand the effect of pH on the formation of electrostatic complexes between lysozyme and low methoxyl (LM) pectin, mixtures were prepared at a fixed lysozyme concentration (0.714g.L) by progressive addition of LM pectin (from 0 to 4g.L). Turbidity analysis allowed to determine specific conditions of pH and lysozyme/LM pectin ratio for optimal complex aggregation. The intrinsic fluorescence enhancement observed upon binding of LM pectin to lysozyme was correlated with the formation of intermolecular aggregates. Conversely, the intrinsic fluorescence decrease observed at higher LM pectin amounts was correlated with the dissociation of intermolecular aggregates. UV absorption spectroscopy showed modifications in lysozyme conformation during both the aggregation phase and the dissociation phase. The role of electrostatic interactions in the formation of lysozyme/LM pectin complexes is discussed in relation to the overall structure and the charge density profile of the two biopolymers.
为了了解pH对溶菌酶与低甲氧基（LM）果胶之间静电复合物形成的影响，通过逐步添加LM果胶（从0至4g.L），在固定的溶菌酶浓度（0.714g.L）下制备混合物。浊度分析有助于确定pH和溶菌酶/LM果胶比例的特定条件，以实现最佳的复合物聚集。观察到LM果胶与溶菌酶结合时内在荧光增强，这与分子间聚集体的形成相关。相反，在较高LM果胶量下观察到的内在荧光降低与分子间聚集体的解离相关。紫外吸收光谱显示在聚集阶段和解离阶段溶菌酶构象均发生改变。结合两种生物聚合物的整体结构和电荷密度分布，讨论了静电相互作用在溶菌酶/LM果胶复合物形成中的作用。
