Azari-Anpar Mojtaba, Jahanbin Kambiz, Degraeve Pascal, Yazdi Farideh Tabatabaei, Adt Isabelle, Oulahal Nadia, Le Cerf Didier
Univ Lyon, Université Claude Bernard Lyon 1, ISARA Lyon, BioDyMIA Research Unit, 155 rue Henri de Boissieu, F-01000 Bourg en Bresse, France; Ferdowsi University of Mashhad, Faculty of Agriculture, Department of Food Science and Technology, Mashhad 91775-1163, Iran.
Shahrood University of Technology, Faculty of Agricultural Engineering, Department of Food Science and Technology, Shahrood, Iran.
Int J Biol Macromol. 2023 Aug 15;246:125599. doi: 10.1016/j.ijbiomac.2023.125599. Epub 2023 Jun 28.
This paper describes the structural elucidation of Leuconostoc mesenteroides P35 exopolysaccharide (EPS-LM). Ln. mesenteroides P35 strain was isolated from a French goat cheese for its capacity to produce EPS increasing the viscosity of a whey-based fermentation medium. The chemical structure of EPS-LM analysis was elucidated by determination of optical rotation degree, macromolecular characterization, sugar units and methylation analyses, FT-IR, 1D NMR spectroscopy (H and C NMR), 2D NMR spectroscopy (HH COSY, HSQC and HMBC). EPS-LM was a high molecular weight (ranging from 6.7 × 10 Da to 9.9 × 10 Da) dextran that is composed of only d-glucose units containing α (1 → 6) linkages and paltry α (1 → 3) branches. Since polysaccharide-protein interactions can be exploited to control and design food matrices, EPS-LM interactions with bovine serum albumin (the main constituent of bovine plasma) were investigated by surface plasmon resonance (SPR). Kinetic properties of EPS-LM binding with immobilized BSA via showed an increase of EPS-LM affinity (equilibrium constant (K)) for BSA from (2.50 ± 0.01) × 10 M at 298 K to (9.21 ± 0.05) × 10 M at to 310 K. The thermodynamic parameters revealed that van der Waals and hydrogen binding forces play a major role in the interaction of EPS-LM with BSA. However, EPS-LM-BSA interaction was non-spontaneous, entropy driven and an EPS-LM - BSA binding process was endothermic (ΔG > 0). The structural findings suggested that Ln. mesenteroides P35 α-D-glucan might find widespread technological applications in the biopolymer, medical and food industries.
本文描述了肠系膜明串珠菌P35胞外多糖（EPS-LM）的结构解析。肠系膜明串珠菌P35菌株是从法国山羊奶酪中分离出来的，因其具有产生能增加乳清基发酵培养基粘度的胞外多糖的能力。通过测定旋光度、大分子表征、糖单元和甲基化分析、傅里叶变换红外光谱（FT-IR）、一维核磁共振波谱（氢谱和碳谱）、二维核磁共振波谱（HH COSY、HSQC和HMBC）对EPS-LM的化学结构进行了解析。EPS-LM是一种高分子量（范围从6.7×10 Da至9.9×10 Da）的葡聚糖，仅由含有α(1→6)连接且少量α(1→3)分支的d-葡萄糖单元组成。由于多糖-蛋白质相互作用可用于控制和设计食品基质，因此通过表面等离子体共振（SPR）研究了EPS-LM与牛血清白蛋白（牛血浆的主要成分）的相互作用。EPS-LM与固定化牛血清白蛋白结合的动力学性质表明，EPS-LM对牛血清白蛋白的亲和力（平衡常数(K)）从298 K时的(2.50±0.01)×10 M增加到310 K时的(9.21±0.05)×10 M。热力学参数表明，范德华力和氢键在EPS-LM与牛血清白蛋白的相互作用中起主要作用。然而，EPS-LM-牛血清白蛋白相互作用是非自发的、熵驱动的，且EPS-LM-牛血清白蛋白结合过程是吸热的（ΔG>0）。结构研究结果表明，肠系膜明串珠菌P35α-D-葡聚糖可能在生物聚合物、医学和食品工业中得到广泛的技术应用。
