应用糖基化碳量子点研究甘露糖与致病菌之间的相互作用

发布时间：2018-01-03 03:44

本文关键词：应用糖基化碳量子点研究甘露糖与致病菌之间的相互作用　出处：《分析测试学报》2017年11期 　论文类型：期刊论文

【摘要】：以柠檬酸为碳源,通过水热法制备得到荧光碳量子点(CQDs),基于其表面的—COOH,将4-氨基苯基-α-D-吡喃甘露糖苷以共价键的方式固定在CQDs表面,得到甘露糖基化碳量子点(Man-CQDs),并通过荧光竞争法,结合Scatchard方程计算了Man-CQDs与大肠杆菌JM109、大肠杆菌DH5a和沙门氏菌S.123443的结合常数Ka。实验得到CQDs的粒径为26 nm,最大发射波长为445 nm,荧光产率相较于54%硫酸奎宁为76%,Man-CQDs荧光强度与CQDs相比基本保持不变,通过苯酚-硫酸法计算得到Man-CQDs浓度为2.832 mmol/L,Man-CQDs纳米颗粒中甘露糖含量约为40%。根据Man-CQDs、D-Mannose与致病菌竞争结合实验,结合Scatchard模型方程,计算得到Man-CQDs与大肠杆菌JM109的结合常数Ka=2.39×103L/mol,Man-CQDs与沙门氏菌S.123443的结合常数Ka=1.17×105L/mol,Man-CQDs与大肠杆菌DH5a无有效结合。研究结果显示,该方法可用于甘露糖与致病菌非共价结合的结合常数测定,为研究糖与致病菌相互作用提供了参考。
[Abstract]:Using citric acid as carbon source, the fluorescent carbon quantum dots (CQDsN) were prepared by hydrothermal method, based on the surface of -COOH. 4-aminophenyl- 伪 -Dpyrannan glycoside was covalently bonded on the surface of CQDs to obtain mannoglycosylated carbon quantum dot Man-CQDsN, and the fluorescence competition law was adopted. Man-CQDs and Escherichia coli JM109 were calculated with Scatchard equation. The binding constant of Escherichia coli DH5a and Salmonella S.123443 was Ka. the particle size of CQDs was 26 nm and the maximum emission wavelength was 445 nm. Compared with 54% quinine sulfate, the fluorescence yield of Man-CQDs was 76%. The fluorescence intensity of Man-CQDs remained basically unchanged compared with CQDs. The concentration of Man-CQDs was 2.832 mmol/L calculated by phenol-sulfuric acid method. The content of mannose in the Man-CQDs nanoparticles is about 40. According to Man-CQDsSX D-Mannose combined with pathogenic bacteria competition test. The binding constant of Man-CQDs to Escherichia coli JM109, Ka=2.39 脳 103L / mol, was calculated by using Scatchard model equation. The binding constant of Man-CQDs to S. 123443 was Ka=1.17 脳 105 L / mol. The results showed that this method could be used for the determination of noncovalent binding constants between mannose and pathogenic bacteria. It provides a reference for the study of the interaction between sugar and pathogenic bacteria.
【作者单位】：重庆大学化学化工学院;新型微纳器件与系统技术重点学科实验室;微纳系统及新材料技术国际研发中心;重庆大学光电工程学院微系统研究中心;重庆理工大学化学化工学院;
【基金】：重庆市科学技术委员会社会民生科技创新一般项目(cstc2015shms zx00014) 重庆市科学技术委员科技惠民计划项目(cstc2015jcsf8001)
【分类号】：O657.3;R378
【正文快照】： 致病菌对宿主细胞的粘附主要通过致病菌菌毛/鞭毛末端的凝集素与宿主细胞表面聚糖发生选择性识别结合完成,从而导致炎症和痢疾等疾病[1]。在细胞水平上定量研究致病菌与糖的相互作用,以及在分子水平上研究凝集素与糖的相互作用,均能为致病菌粘附机制的研究、致病菌的特异性检

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