INRAE, BIA, F-44316 Nantes, France; AMU, INRAE, INSERM, C2VN, Marseille, France.
AMU, INRAE, INSERM, C2VN, Marseille, France.
J Colloid Interface Sci. 2021 May;589:229-241. doi: 10.1016/j.jcis.2021.01.002. Epub 2021 Jan 5.
The structures of fed state intestinal assemblies containing bile components, dietary fat, and fat-soluble vitamins are not well known, although they are involved in lipid transport. In this study, several methods were used to investigate structural transitions upon various dietary lipids or various fat-soluble vitamins incorporation in bile intestinal assemblies. In particular, DLS and turbidimetry were used to study transition points as a function of component concentration, and cryo-TEM and SAXS were used to resolve assembly structures at microscopic and supramolecular scales, respectively. Results showed that increasing the concentration of dietary lipids in bile assembly induced a transition from core-shell micelles to unilamellar vesicles (except with caprylate lipids, always yielding micelles). In these specific assemblies, increasing the concentration of a fat-soluble vitamin either induced a systematic structural transition, defining a solubilization capacity (α-tocopherol or phylloquinone), or induced a structural transition only in micelles (retinol), or did not induce any structural transition up to very high concentrations (cholecalciferol). Using SAXS data, ideal molecular organizations are proposed for assemblies in the absence or presence of α-tocopherol.
肠道内含胆汁成分、膳食脂肪和脂溶性维生素的组装体的结构目前还不明确，尽管它们与脂质转运有关。在这项研究中，使用了几种方法来研究在不同膳食脂质或不同脂溶性维生素掺入胆汁肠道组装体时发生的结构转变。特别是，DLS 和浊度法用于研究作为组分浓度函数的转变点，而 cryo-TEM 和 SAXS 分别用于在微观和超分子尺度上解析组装结构。结果表明，胆汁组装体中膳食脂肪浓度的增加诱导了从核壳型胶束到单层囊泡的转变（除了辛酸酯脂质，始终生成胶束）。在这些特定的组装体中，增加脂溶性维生素的浓度要么诱导系统结构转变，定义了溶解能力（α-生育酚或叶绿醌），要么仅在胶束中诱导结构转变（视黄醇），要么在非常高的浓度下不诱导任何结构转变（胆钙化醇）。使用 SAXS 数据，提出了在不存在或存在α-生育酚时组装体的理想分子组织。
