使用原子力显微镜对酪蛋白纳米凝胶颗粒的形貌和纳米力学表征,Food Hydrocolloids

当前位置： X-MOL 学术 › Food Hydrocoll. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

使用原子力显微镜对酪蛋白纳米凝胶颗粒的形貌和纳米力学表征
Food Hydrocolloids ( IF 11.0 ) Pub Date : 2018-10-01 , DOI: 10.1016/j.foodhyd.2018.03.029
Asma Bahri , Marta Martin , Csilla Gergely , Sylvie Marchesseau , Dominique Chevalier-Lucia

摘要酪蛋白胶束（CM）是一种多孔胶体磷蛋白-矿物质复合物，天然存在于牛奶中以传递矿物质，也具有多种特性，可以确保其用作生物活性剂的纳米载体。CM 结构根据物理化学条件不稳定，可以通过使用转谷氨酰胺酶 (TGase) 的胶束内交联来提高其稳定性，从而诱导一种称为酪蛋白纳米凝胶的强化结构。本研究的目的是在类天然液体环境（无乳糖模拟牛奶超滤液，SMUF）中使用原子力显微镜 (AFM) 研究由 TGase (TG-CM) 交联的酪蛋白纳米凝胶颗粒的形态和纳米力学。在 AFM 之前，TG-CM 被抗磷酸-Ser/Thr/Tyr 单克隆抗体捕获，该抗体通过碳二亚胺化学共价结合到镀金的载玻片上。表面形貌和尺寸特性评估显示，与天然 CM 相比，TG-CM 的尺寸增加，TG-CM 的特征是平均宽度为 264 ± 7 nm，平均高度为 111 ± 5 nm。TG-CM 显示出相对较高的接触角 (62°)，表明这些颗粒在吸附到基材上后扁平化有限。然后在单个 TG-CM 上施加低压痕力来评估 TG-CM 弹性。由于胶束结构内的分子内重排，TGase 处理导致了 CM 纳米力学的显着改变。TG-CM 的弹性分布显示三个弹性峰集中在 219 ± 14 kPa、536 ± 14 kPa 和 711 ± 11 kPa。

"点击查看英文标题和摘要"

Topographical and nanomechanical characterization of casein nanogel particles using atomic force microscopy

Abstract Casein micelle (CM), porous colloidal phosphoprotein-mineral complex, naturally present in milk to deliver minerals, also has several features, which could ensure its use as nanocarrier for bioactives. CM structure being not steady according to the physico-chemical conditions, its stability can be improved by intra-micellar cross-linking using transglutaminase (TGase) inducing a strengthened structure called casein nanogel. The aim of this research was to investigate the morphology and nanomechanics of casein nanogel particles cross-linked by TGase (TG-CM) using atomic force microscopy (AFM) in native-like liquid environment (lactose-free simulated milk ultrafiltrate, SMUF). Prior to AFM, TG-CM were captured by anti-phospho-Ser/Thr/Tyr monoclonal antibodies covalently bound to a gold-coated slide via carbodiimide chemistry. Surface topography and size properties evaluation revealed an increase in size of TG-CM compared to native CM, TG-CM being characterized by a mean width of 264 ± 7 nm and a mean height of 111 ± 5 nm. TG-CM displayed a relatively high contact angle (62°) indicating a limited flattening of these particles after adsorption on the substrate. The TG-CM elasticity was then evaluated applying low indentation forces on single TG-CM. The TGase treatment led to a significant modification of CM nanomechanics attributed to intramolecular rearrangements within the micellar structure. The elasticity distribution of TG-CM revealed three elasticity peaks centered at 219 ± 14 kPa, 536 ± 14 kPa and 711 ± 11 kPa. The lower elasticity peak is related to the native CM nanomechanical signature and the two stiffer peaks were attributed to the substantial changes in the TG-CM structure.

更新日期：2018-10-01

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南