Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111, Lobachevsky Str. 2/31, Kazan, Russia.
The Department of Biology and Biotechnology, Vyatka State University, 610000, Moskovskaya Str. 36, Kirov, Russia; Nanotechnology Research and Education Center, Vyatka State University, 610000, Moskovskaya Str. 39, Kirov, Russia.
Carbohydr Polym. 2019 Jul 15;216:238-246. doi: 10.1016/j.carbpol.2019.03.087. Epub 2019 Mar 30.
Functionally distinct polymers organized on the basis of rhamnogalacturonan I (RG-I) backbone with more than a half of rhamnose residues substituted by the side chains containing mostly galactose were purified from flaxseed mucilage, the primary cell wall of young hypocotyls and tertiary cell walls of bast fibers and characterized by atomic force microscopy. Seed mucilage RG-I with short side chains and unusual O3 substitution showed loose coils or star-like conformations. Primary cell wall RG-I, which included polygalacturonan (PGA) fragments, represented micellar objects and rare long chains. Pure RG-I with long galactan side chains, which was isolated as nascent polysaccharide before its incorporation into the tertiary cell wall of bast fibers was observed as long unbranched objects. RG-I entrapped by cellulose microfibrils in tertiary cell wall was visualized as compact micellar complexes. All types of flax RGs-I tended to aggregate. Relationships between RG-I structure and morphology are discussed.
从亚麻种皮黏胶、幼胚下胚轴初生细胞壁和韧皮纤维次生细胞壁中分离出基于鼠李半乳糖醛酸 I（RG-I）主链的、具有超过一半鼠李糖残基被侧链取代的功能不同的聚合物，这些侧链主要含有半乳糖。利用原子力显微镜对其进行了表征。具有短侧链和不寻常 O3 取代的种皮 RG-I 呈现松散的线圈或星形构象。初生细胞壁 RG-I 包括聚半乳糖醛酸（PGA）片段，呈胶束状物体和稀有的长链。在将其掺入韧皮纤维的次生细胞壁之前作为初生多糖分离出来的具有长半乳糖侧链的纯 RG-I 被观察为长的无支链物体。被纤维素微纤维束缚在次生细胞壁中的 RG-I 被可视化成紧密的胶束复合物。所有类型的亚麻 RG-I 都倾向于聚集。讨论了 RG-I 结构与形态之间的关系。
