4261-27-2Relevant academic research and scientific papers
Bioengineering of Leuconostoc mesenteroides glucansucrases that gives selected bond formation for glucan synthesis and/or acceptor-product synthesis
Kang, Hee Kyoung,Kimura, Atsuo,Kim, Doman
experimental part, p. 4148 - 4155 (2011/10/30)
The variations in glucosidic linkage specificity observed in products of different glucansucrases appear to be based on relatively small differences in amino acid sequences in their sugar-binding acceptor subsites. Various amino acid mutations near active sites of DSRBCB4 dextransucrase from Leuconostoc mesenteroides B-1299CB4 were constructed. A triple amino acid mutation (S642N/E643N/V644S) immediately next to the catalytic D641 (putative transition state stabilizing residue) converted DSRBCB4 enzyme from the synthesis of mainly α-(1→6) dextran to the synthesis of α-(1→6) glucan containing branches of α-(1→3) and α-(1→4) glucosidic linkages. The subsequent introduction of mutation V532P/V535I, located next to the catalytic D530 (nucleophile), resulted in the synthesis of an α-glucan containing increased branched α-(1→4) glucosidic linkages (approximately 11%). The results indicate that mutagenesis can guide glucansucrase toward the synthesis of various oligosaccharides or novel polysaccharides with completely altered linkages without compromising high transglycosylation activity and efficiency.
Structure characterization of polysaccharide isolated from the fruiting bodies of Tricholoma matsutake
Ding, Xiang,Feng, Su,Cao, Mei,Li, Mao-tao,Tang, Jie,Guo, Chun-xiao,Zhang, Jie,Sun, Qun,Yang, Zhi-rong,Zhao, Jian
experimental part, p. 942 - 947 (2011/12/02)
A novel heteropolysaccharide was isolated from the fruiting bodies of Tricholoma matsutake through DEAE-cellulose column and Sephadex G-100 column. The T. matsutake polysaccharide (TMP-A) had a molecular weight of 8.89 × 104 Da and was mainly composed of 4-D-Glc:4,6-D-Glc:3-D-Gal:T-D-Xyl and with the ratio of 7:1:1:1. The structural features of TMP-A were investigated by a combination of total hydrolysis, methylation analysis, gas chromatography-mass spectrometry (GC-MS), scanning electron microscope (SEM), infrared (IR) spectra, nuclear magnetic resonance (NMR) spectroscopy and dynamical analysis of the atomic force microscope (AFM) studies. The results indicated that TMP-A had a backbone of 1,4-β-glucopyranos which branches at O-6 composed of an (1 → 3)-α-galactopyranose residue and terminated with α-xylopyranose residue. Chain conformation study showed that the polysaccharide took random coil compact conformation.
