Lee Hyojeong, Kim Seonmok, Kim Yohan, Jung Seunho
Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, Korea.
Department of Systems Biotechnology & Institute for Ubiquitous Information Technology and Applications (UBITA), Center for Biotechnology Research in UBITA (CBRU), Konkuk University, Seoul 05029, Korea.
Polymers (Basel). 2020 Sep 12;12(9):2073. doi: 10.3390/polym12092073.
produces different types of surface polysaccharides. Among them, cyclic β-(1→2)-d-glucan is located in the periplasmic space of rhizobia and plays an important role in the adaptation of bacteria to osmotic adaptation. Cyclic β-(1→2)-d-glucan (CG), synthesized from 1021, has a neutral and anionic form. In the present study, we characterized the exact chemical structures of anionic CG after purification using size exclusion s (Bio-Gel P-6 and P-2) chromatography, and DEAE-Sephadex anion exchange chromatography. The exact structure of each isolated anionic CG was characterized using various analytical methods such as nuclear magnetic resonance (NMR), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and matrix associated laser desorption ionization-time of Flight (MALDI-TOF) mass spectrometry. The precise chemical structures of novel anionic CG molecules were elucidated by various NMR spectroscopic analyses, including H, C, P, and 2D HSQC NMR spectroscopy. As a result, we discovered that anionic CG molecules have either glycerophosphoryl or succinyl residues at C6 positions of a neutral CG. In addition, the results of MALDI-TOF mass spectrometric analysis confirmed that there are two types of patterns for anionic CG peaks, where one type of peak was the succinylated CG (SCG) and the other was glycerophospholated CG (GCG). In addition, it was revealed that each anionic CG has one to four substituents of the succinyl group of SCG and glycerophosphoryl group of GCG, respectively. Anionic CG could have potential as a cyclic polysaccharide for drug delivery systems and a chiral separator based on the complexation with basic target molecules.
产生不同类型的表面多糖。其中，环状β-(1→2)-D-葡聚糖位于根瘤菌的周质空间，在细菌适应渗透环境中起重要作用。环状β-(1→2)-D-葡聚糖（CG）由1021合成，有中性和阴离子形式。在本研究中，我们使用尺寸排阻色谱（Bio-Gel P-6和P-2）和DEAE-葡聚糖阴离子交换色谱对纯化后的阴离子CG的确切化学结构进行了表征。使用各种分析方法，如核磁共振（NMR）、衰减全反射傅里叶变换红外（ATR-FTIR）光谱和基质辅助激光解吸电离飞行时间（MALDI-TOF）质谱，对每个分离的阴离子CG的确切结构进行了表征。通过各种NMR光谱分析，包括H、C、P和二维HSQC NMR光谱，阐明了新型阴离子CG分子的确切化学结构。结果，我们发现阴离子CG分子在中性CG的C6位置有甘油磷酸基或琥珀酰基残基。此外，MALDI-TOF质谱分析结果证实，阴离子CG峰有两种类型的模式，一种类型的峰是琥珀酰化CG（SCG），另一种是甘油磷酸化CG（GCG）。此外，还发现每个阴离子CG分别有一到四个SCG的琥珀酰基和GCG的甘油磷酸基取代基。基于与碱性靶分子的络合作用，阴离子CG可能有潜力作为药物递送系统的环状多糖和手性分离剂。
