糖链植物疫苗研究与进展

内容简介本书围绕糖链植物疫苗对植物自身免疫的调控,通过与动物疫苗及免疫机制对比,从糖链植物疫苗的实际应用及作用机理两方面介绍糖链植物疫苗。实际应用部分通过对代表性的糖链植物疫苗(几丁聚糖及其寡糖、壳聚糖及其寡糖、葡聚糖及其寡糖、寡聚半乳糖醛酸及糖肽等)在粮食作物、经济作物、蔬菜、果树、花卉     

热紫链霉菌几丁质酶表达及低脱乙酰度壳寡糖制备

壳寡糖具有抗炎、抗肿瘤及激活植物免疫等一系列生物活性.与传统的高脱乙酰度壳寡糖相比,低脱乙酰度壳寡糖可能具有更高生物活性.表达热紫链霉菌几丁质酶基因并使用表达产物水解制备低脱乙酰度壳寡糖;优化并全基因合成热紫链霉菌几丁质酶基因,利用毕赤酵母进行分泌表达,对产物酶的性质进行鉴定;利用表达的几丁质酶水解制备低脱乙酰度壳寡糖,使用超高效液相色谱-四极杆飞行时间质谱(Ultra-performance liquid chromatography quadrupoletime-of-f lightmassspectrometry,UPLC-QTOFMS)对其组分进行分离及鉴定,使用核磁共振(Nuclear magnetic resonance,NMR)确定其末端结构特征.结果显示,表达的几丁质酶蛋白浓度为0.20 mg/mL,最适pH为5.6,最适温度为60℃,酶活为0.98 U/mL,该酶在80℃及以下时较稳定,该酶水解制备的低脱乙酰度壳寡糖中包含至少35种聚合度2-17、不同脱乙酰度的壳寡糖组分,这些组分的还原末端主要由N-乙酰氨基葡萄糖组成,非还原末端同时包含氨基葡萄糖及N-乙酰氨基葡萄糖.本研究表明毕赤酵母分泌表达的热紫链霉菌几丁质酶具有较好的热稳定性,具有应用于低脱乙酰度壳寡糖规模制备的潜力.(图4表1参22)     

壳寡糖对镉致肝脏损伤的保护作用及机理研究

为研究壳寡糖(chitooligosaccharide, COS)对镉致肝脏损伤的作用及机制,选用32只体质量在16～19 g的健康雌性C57BL/6小鼠,随机分为4个组：空白对照组(Control)、氯化镉造模组(Cd)、壳寡糖组(COS)、壳寡糖+氯化镉组(COS+Cd)。空白对照组和氯化镉造模组每日饲喂基础日粮,饮用纯净水;壳寡糖组和壳寡糖+氯化镉组每日饲喂基础日粮,在饮水中添加0.3 g·L^-1 COS。于第28天对氯化镉造模组和壳寡糖+氯化镉组小鼠采取腹腔注射5.45 mg·kg^-1氯化镉的处理,12 h后采样。结果显示：(1)添加COS缓解了重金属镉累积导致的肝细胞颗粒变性、细胞结构模糊等病理症状;(2)COS缓解了由于重金属镉暴露导致的氧化应激,激活了小鼠体内的氧化型谷胱甘肽(oxidized glutathione, GSSG)/谷胱甘肽(glutathione, GSH)系统(P<0.05),显著减少了肝脏由于氧化损伤而产生的活性氧(reactive oxygen species,ROS)(P<0.05),有利于...     

酵母双杂交筛选OIPK相互作用蛋白

前期研究发现烟草中一个壳寡糖诱导的Ser/Thr蛋白激酶(Oligochitosan induced protein kinase,OIPK)在壳寡糖诱导的烟草抗性反应中起着重要作用.目前在烟草中发现OIPK基因的两个选择性剪接体:OIPKL和OIPKS,其中OIPKL是3个选择性剪接体中序列最长的.为进一步研究OIPK在壳寡糖诱导植物抗性中起的作用,本研究采用酵母双杂交方法,以pGBKT7-OIPKL为诱饵质粒,筛选构建在pACT2载体上的烟草cDNA文库,寻找OIPKL的相互作用蛋白.结果表明OIPKL蛋白在酵母中可以和烟草的S-腺苷甲硫氨酸合成酶、泛素激活酶E1、丙酮酸激酶、过氧化物酶相互作用.实验结果为研究壳寡糖诱导抗性机理提供了一定依据.图3参26     

配备脉冲安培检测器的高效阴离子交换色谱(HPAE-PAD)流动相的配制

在检测碳水化合物的领域中,HPAE-PAD是一项广泛应用的技术.这一技术不仅仅局限于分析单糖、双糖、寡糖、小分子多糖、硅酸和其它糖酸,还包括糖醇、磷酸糖和核苷糖.HPAE-PAD已经代替了其它许多碳水化合物的分析技术,对小分子碳水化合物(如单糖)和大分子碳水化合物(如寡糖)HPAE-PAD都能实现高效分离.     

具抗病毒黄精寡糖核心片段的分离纯化与四糖结构

寡糖极性大、异构体多、结构复杂,对其研究尤其是对天然来源寡糖的分离纯化与结构确认具有重要的理论和临床应用价值.以传统中药百合科黄精属植物多花黄精为原料,从分离纯化出的具有抗病毒活性的核心寡糖片段出发,制备了聚合度单一的黄精四糖,并以UV、IR、NMR、ESI-MS n、HPLC、GC-MS等多种手段对其组成与结构进行充分解析.结果表明四糖虽然聚合度单一,但仍存在多种同分异构体,且以直链结构的四糖为主,其中→2)-β-D-Fruf以及(2→1)-β-D-Fruf的含量最多,2→6)-β-D-Fruf较低,并且有的同分异构体具有典型的β-D-Fruf-(2→1)-α-D-Glcp结构,但含量甚微.本研究从具抗病毒活性的黄精寡糖分离纯化获得黄精四糖并阐明结构,可为进一步构建活性寡糖小分子和指导多糖类化合物新药设计奠定基础.     

壳寡糖诱导转反义mapk基因烟草的TMV抗性和PAL活性研究

壳寡糖具有诱导植物对病原物防御反应的作用,而PAL活性的升高通常被认为是发生抗性反应的标志之一.本文以mapk基因受到反义抑制的转基因枯斑三生烟草为试材,比较了壳寡糖诱导后转基因型和野生型烟草的PAL活性变化及对TMV抗性的变化.由实验结果初步推测,在壳寡糖诱导的植物抗性信号通路中,mapk可能为PAL的一个重要的上游基因,同时mapk在烟草抗TMV信号转导中亦为一个重要组分.图4表2参13     

糖蛋白和寡糖化学进展

本文简要介绍近年来糖蛋白和寡糖化学的进展,包括糖蛋白中寡糖链的分类和寡糖链的结构分析方法,糖蛋白的生物合成和寡糖的化学合成。     

高效液相色谱联用高分辨质谱和电喷雾检测器定性和定量检测水苏糖提取物中寡糖成分

本文建立了高效液相色谱联用电喷雾检测器(HPLC-CAD)检测水苏糖中寡糖成分的方法.利用高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱(HPLC-LTQ/Orbitrap-MS)鉴定了水苏糖中包括蔗糖、棉子糖、甘露三糖和毛蕊花糖等多种寡糖成分.方法采用XBridge BEH Amide色谱柱(4.6 mm×250 mm,5.0μm)，乙腈-水(70:30)为流动相进行测定.结果表明，蔗糖、棉子糖、甘露三糖质量浓度与峰面积分别在2.763—110.5μg·mL^-1、9.906—396.2μg·mL^-1和12.24—489.5μg·mL^-1范围内呈现良好线性关系(r>0.999)，平均回收率(n=9)为100.1%—103.4%,RSD为1.09%—2.49%.该方法灵敏度高，准确性好，操作简便，可用作水苏糖提取物质量控制的有效方法.     

离子色谱与三重四极杆质谱TSQ Altis联用实现10种寡糖的同时分析检测

本文建立了针对10种寡糖,包括甘露糖醛酸（M）和古罗糖醛酸（G）的离子色谱串联三重四极杆质谱的分析方法.优化后的离子色谱条件：Thermo Scientific Dionex IonPac TM AS19-4μm （2 mm×250 mm, Analytical）,200 mmol·L^-1氢氧化钠-水为淋洗液,流速0.3 mL·min^-1,柱温30℃,电导检测器后连外接泵,三通阀加0.25 mL·min^-1乙腈.采用ESI源,扫描方式为选择反应检测.结果表明,离子色谱对不同聚合度的甘露糖醛酸和古罗糖醛酸有很好的保留和分离效果,三重四极杆质谱相比传统检测手段具有优异的灵敏度和高选择性;稳定性良好,连续进样5针,RSD均小于6.08%;标曲线性关系良好,R2≥0.9990;方法检出限0.34μg·L^-1;加标回收率均≥90.2%,本方法可用于寡糖的定性及定量分析.     

功能性低聚糖在饲料添加剂中的应用

低聚糖或称寡糖是由2-10个单糖分子通过糖苷键连接组成的小聚合体。作为一种新型的功能性饲料添加剂,在动物体内可促进消化道有益菌的生长,抑制有害病原菌的繁殖,提高动物机体免疫力。多数试验研究表明,饲料中添加适量低聚糖,能在较大程度上替代抗生素而改善动物健康,增强抗病力,提高家禽及幼龄动物成活率,提高动物的生长增重和饲料转化率。     

Synthesis of substituted cyclodextrins

Environmental Chemistry Letters - Cyclodextrins are naturally occurring, non-toxic and biodegradable cyclic oligosaccharides. The main feature of cyclodextrins is the ability to encapsulate...     

A review on thermal analyses of cyclodextrins and cyclodextrin complexes

Environmental Chemistry Letters - Cyclodextrins are valuable natural or synthetically modified cyclic oligosaccharides that are widely used for ameliorating properties of biologically active...     

Identification of a sex pheromone from a rotifer

The first isolation and characterization of a sex pheromone from a zooplankter is reported. A 29 kdalton glycoprotein on the surface of females of the marine rotifer Brachionus plicatilis acts as a contact-mating pheromone. This glycoprotein (gp29) is glycosylated with oligosaccharides containing Nacetylglucosamine, mannose, and fucose residues, and these oligosaccharides are necessary for male recognition of females. Males detect this signal by contact chemoreception with receptors located in their corona. Binding of purified glycoprotein to male receptors reduces mating attempts by 93%. An antibody to the glycoprotein binds to females, reducing male mating attempts by 86%. When purified gp29 is bound to sepharose beads, it is sufficient to elicit male mating behavior. This glycoprotein is likely to play a key role in the evolution and maintenance of reproductive isolation in rotifers.     

Carbohydrases of some marine invertebrates with notes on their food and on the natural occurrence of the carbohydrates studied

Extracts of 22 marine invertebrates were incubated with 29 different carbohydrates, and enzyme spectra estimated from chromatograms. Enzymatic activities were quantified as reducing sugar in 14 of these species. Significant hydrolysis of laminaran, glycogen, and amylose was found in nearly all species, while hydrolysis of oligosaccharides and structural polysaccharides in most cases was weak or absent. The strongest overall degradation of carbohydrates was found among crustaceans. Enzymatic degradation of laminaran shows some relation to food, but the spectra of carbohydrases are not directly predictable from knowledge of natural food sources. Some carbohydrases (sucrase, cellobiase, lactase) could not be explained by ecological considerations. The results indicate that structural polysaccharides are utilized only to a small extent.     

Professor Casu’s contribution to cyclodextrins,the remarkable cage-shaped molecules: a review

Cyclodextrins are cage-shaped molecules having the remarkable ability to trap smaller compounds, and have thus led to applications in many disciplines such as medicine to increase the bioavailability of hydrophobic drugs. This historical review summarizes the outstanding contribution of the late Professor Benito Casu to cyclodextrin research and, more generally, to the chemistry and biochemistry of linear and cyclic oligosaccharides, polysaccharides, glycosaminoglycans, and heparin. Professor Casu was the first to elucidate the structure and conformations of cyclodextrins by infrared spectroscopy and proton nuclear magnetic resonance (NMR). In particular, he showed that trapped compounds induced a shift of H peaks in NMR due to the shielding effect of cyclodextrins. He also demonstrated that the d-glucopyranose cyclodextrin units are in the C-1 chair conformation by analyzing α-cyclodextrin by NMR in dimethylsulfoxide-d₆.

     

Remediation technologies using cyclodextrins: an overview

Nowadays, the human activity and the modern way of life are responsible for the increase of the environmental pollution. Industrial processes generate a variety of molecules that may pollute air, water, and soils due to negative impacts for ecosystems and humans. The development of innovative remediation technologies has thus emerged as a significant environmental priority. Within this scope, supramolecular chemistry, which is a recent discipline, could provide solutions. In particular, cyclodextrins (CDs) are a family of cyclic oligosaccharides having a low-polarity cavity in which organic compounds of appropriate shape and size can form inclusion complexes. This unique property makes them suitable for application in environmental protection. Here, we review the use of cyclodextrins and cyclodextrin derivatives in remediation technologies. Accordingly, the present review shows the advantages of using CDs in soil, groundwater, wastewater, and atmosphere remediation. Resulting processes are highly versatile, since the complexing ability of CD is applicable to a wide range of pollutants. They may also been referred to green processes, according to the CD innocuity. Moreover, as inclusion phenomena correspond to reversible equilibriums, a major trend in the CD environmental application field is to develop methods, which combine supramolecular chemistry and irreversible processes, as advanced oxidation or biodegradation. Such processes might lead to a complete remediation of pollutants and eventually to the CD recycling.     

Distribution of glycosylglycerols and oligosaccharides in the marine environment and their ecological significance in the deep sea

Determination of low molecular weight carbohydrates in marine environments indicated that 1-O--D-galactosylglycerol, 6-O--D-galactosyl-1-O--D-galacto-sylglycerol, sucrose, laminaribiose and laminaritriose are widely distributed in seawaters, suspended and sinking particles, and sediments in coastal as well as in deep-sea waters [e.g. Mikawa Bay and Sagami Bay, Kumano Nada (offshore Japan), and northwest North Pacific Ocean, Bering Sea and Antarctic Ocean: collections during 1978–1984]. Identification of these glycosylglycerols and oligosaccharides in algal cells such as a flagellate (Olisthodisus luteus), blue-green algae (e.g.Trichodesmium sp.) and a diatom (Reptocylindrus denicus) strongly suggests that these sugars are photosynthetically produced by algae in the euphotic zone and are then rapidly transported to the deep sea as sinking particles which can be collected by sediment-trap experiments. The rapid decay rate of low molecular weight carbohydrates by microorganisms suggests that the transported sugars provide energy substrates for microorganisms living in the deep sea.Please address all requests for reprints to Dr. Handa at Nagoya University     

Purification and characterization of an endo-1, 4-β-D glucanase from the cellulolytic system of the wood-boring marine mollusk<Emphasis Type="Italic"> Lyrodus pedicellatus</Emphasis> (Bivalvia: Teredinidae)

The soluble fraction of crude tissue homogenates prepared from intact specimens of the shipworm Lyrodus pedicellatus Quatrefages was observed to increase the reducing sugar content of solutions of carboxymethylcellulose (CMC). The predominant CMCase activity detected in these lysates by zymography corresponds to a polypeptide of approximately 40 kDa. This protein, designated Lp-egl-1, was purified and characterized. Experiments described in this study were performed in 1997 using L. pedicellatus from a culture maintained at the Woods Hole Oceanographic Institution. Purified Lp-egl-1 increases reducing sugar content of solutions of CMC and suspensions of phosphoric acid–swollen cellulose, decreases viscosity of CMC solutions, and cleaves the oligosaccharides cellopentaose and cellotetraose internally to release cellotriose and cellobiose. It has no detectable activity against microcrystalline cellulose, cellotriose, cellobiose, or p-nitrophenyl -D-glucopyranoside and does not release glucose from any tested substrate. These results are consistent with the conclusion that Lp-egl-1 is an endo-1, 4--D glucanase (E.C. 3.2.1.4). The K _m value of Lp-egl-1 for CMC is 20 mg ml^–1. The enzymatic activity is inhibited by cellobiose and cellotriose, but not by glucose. Lp-egl-1 differs in molecular mass as well as kinetic and immunological properties from a previously described endoglucanase secreted by a cultivable endosymbiont of shipworms, Teredinibacter turnerae Distel et al., 2002. It has not been determined whether Lp-egl-1 is a product of the L. pedicellatus nuclear genome or of an associated symbiotic microbe.Communicated by J.P. Grassle, New Brunswick     

Relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China

This paper studied the relationship between heavy metal concentrations of herbaceous plants and soils at four Pb-Zn mining sites in Yunnan, China. 50 herbaceous plant samples of 9 plant species from 4 families and 50 soil samples were collected and then ana1yzed for the tota1 concentrations of Pb, Cd, and Zn. The results showed that the average concentrations of Pb, Cd, and Zn in soil samples were 3772.83, 168.81, and 5385.65 mg/kg, respectively. The average concentrations of Pb, Cd, and Zn were 395.68, 28.14, and 1664.20 mg/kg in the shoots, and 924.12, 57.25, and 1778.75 mg/kg in the roots, respectively. Heterospecific plants at the same site and conspecific plants at various sites had different average levels of Pb, Cd, and Zn, both in the shoots and the roots. Enrichment coefficients of Pb, Cd, and Zn were greater than 1 in 2, 3, and 9 herbaceous plant samples, respectively. Translocation factors of Pb, Cd, and Zn were greater than 1 in 10, 17, and 25 herbaceous plant samples, respectively. In all 50 samples, the concentrations of Pb, Cd, and Zn between the shoots and the roots, the shoots, and the soils, and the roots and the soils had significant positive relationships.