Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomedical Research, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, the Netherlands; Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands; NutriLeads B.V., Bronland 12N, 6708 WH Wageningen, the Netherlands.
Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomedical Research, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, the Netherlands.
Carbohydr Polym. 2025 Jan 1;347:122730. doi: 10.1016/j.carbpol.2024.122730. Epub 2024 Sep 10.
Carrot rhamnogalacturonan-I (cRG-I) is a polydisperse polysaccharide with molecular weights of 7-250 kDa. Using size exclusion chromatography cRG-I was fractionated and pooled in fractions (PF1-6). All fractions contained the same RG-I monosaccharides and similar glycosidic linkages although in varying relative amounts. The main differences were in rhamnose substitution, arabinan- and galactan side chain length and in levels of acetylation and methyl esterification. Atomic force microscopy showed either spheric or elongated structures for cRG-I and its derived fractions. To gain insight in the structure-function relationship of cRG-I, the immunomodulatory effect of the six fractions and their saponified derivatives was assessed in vitro. All fractions, except PF2, dose-dependently stimulated TNFα, IL-6, IL-1β, IL-8 and IL-10 production in peripheral blood mononuclear cells (PBMCs) of three healthy donors. Cytokine levels were largely influenced by the Mw and degree of esterification of the individual fractions. Notably, the highest Mw fraction (100 kDa) displayed the most potent activity, which was strongly reduced after the removal of ester residues by saponification. In contrast, the 75 kDa Mw population (PF2) proved inactive while its saponified counterpart exhibited substantial immunomodulatory activity. This confirmed the role of ester residues on the immune profile of RG-I subpopulations.
胡萝卜鼠李半乳糖醛酸聚糖 I（cRG-I）是一种多分散的多糖，分子量为 7-250 kDa。使用凝胶渗透色谱法将 cRG-I 进行分级，并在级分（PF1-6）中汇集。所有级分均含有相同的 RG-I 单糖和相似的糖苷键，尽管相对含量不同。主要差异在于鼠李糖取代、阿拉伯聚糖和半乳聚糖侧链长度以及乙酰化和甲酯化水平。原子力显微镜显示 cRG-I 及其衍生级分呈球形或伸长结构。为了深入了解 cRG-I 的结构-功能关系，评估了六种级分及其皂化衍生物在体外对免疫调节的影响。除了 PF2 之外，所有级分均以剂量依赖的方式刺激了三个健康供体的外周血单核细胞（PBMC）中 TNFα、IL-6、IL-1β、IL-8 和 IL-10 的产生。细胞因子水平主要受各个级分的 Mw 和酯化程度的影响。值得注意的是，最高 Mw 级分（100 kDa）表现出最强的活性，而皂化去除酯基后，其活性大大降低。相比之下，75 kDa Mw 级分（PF2）证明无活性，而其皂化对应物则表现出显著的免疫调节活性。这证实了酯基对 RG-I 亚群免疫谱的作用。
