maltoheptaose | 137767-17-0

• 物质功能分类: 生物化工 - 糖类化合物 - 寡糖
• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: maltoheptaose
• 英文别名: Maltoheptose；(2R,3R,4S,5S,6R)-2-[(2R,3S,4R,5R,6R)-6-[(2R,3S,4R,5R,6R)-6-[(2R,3S,4R,5R,6R)-6-[(2R,3S,4R,5R,6R)-6-[(2R,3S,4R,5R,6R)-4,5-dihydroxy-2-(hydroxymethyl)-6-[(2R,3S,4R,5R,6S)-4,5,6-trihydroxy-2-(hydroxymethyl)oxan-3-yl]oxyoxan-3-yl]oxy-4,5-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-4,5-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-4,5-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-4,5-dihydroxy-2-(hydroxymethyl)oxan-3-yl]oxy-6-(hydroxymethyl)oxane-3,4,5-triol
• CAS: 137767-17-0
• 化学式: C₄₂H₇₂O₃₆
• 分子量: 1153.01
• InChiKey: BNABBHGYYMZMOA-AHIHXIOASA-N

物化性质

• 沸点：
  1428.2±65.0 °C(Predicted)
• 密度：
  1.88±0.1 g/cm3(Predicted)
• 物理描述：
  Solid
• 碰撞截面：
  303.3 Ų [M+H]+ [CCS Type: DT, Method: stepped-field]

计算性质

• 辛醇/水分配系数(LogP)：
  -15.5
• 重原子数：
  78
• 可旋转键数：
  19
• 环数：
  7.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  585
• 氢给体数：
  23
• 氢受体数：
  36

反应信息

• 作为反应物：
  描述：

  maltoheptaose 在 水 作用下， 以 氘代二甲亚砜 为溶剂， 反应 3.0h， 生成 5-羟甲基糠醛
  参考文献：
  名称：

  水对环糊精中非末端α-糖苷键的水解裂解产生二糖亚砜-水混合物中单糖及其衍生物的影响

  摘要：

  研究了α-，β-和γ-环糊精中非末端α-1,4-糖苷键和d-麦芽糖中异头末端的水解裂解，以研究α-，β- ，而γ-环糊精比d-麦芽糖慢。通过应用原位13 C NMR光谱和使用二甲亚砜（DMSO）-水混合物在宽广的水摩尔分数x w下研究了水和温度的影响=在120–180°C的温度下为0.004–1。非异头糖苷键的裂解速率常数比异头端糖苷键的裂解速率常数小6-10倍。通过将端基末端d-葡萄糖单元的keto-enol互变异构化为d-果糖，可大大加快糖苷键的裂解。环糊精的尺寸越小，由于环应变而导致的键断裂越容易。对于环糊精和d-麦芽糖以及d，观察到裂解率随着水含量的降低而显着提高。-纤维二糖。这表明了孤立水的重要作用，因为有机偶极非质子传递溶剂DMSO的存在阻止了氢与其他水分子的氢键键合，并且具有更多的裸露部分电荷和更高的反应性。通过将水含量调节至x w = 0.30，可以在非催化转化中获得高达6

  DOI：

  10.1021/jp412628y
• 作为产物：
  描述：

  β-环糊精 在 cyclomaltodextrinase 作用下， 以 aq. phosphate buffer 为溶剂， 反应 6.0h， 生成 maltoheptaose
  参考文献：
  名称：

  含有共表达两种酶的透化全细胞生物催化剂促进淀粉合成麦芽七糖 (G7)

  摘要：

  麦芽七糖 (G7) 是麦芽糖糊精的混合物之一，广泛用于食品、制药和化妆品行业。将上述两个基因克隆到质粒中并转化宿主，构建了同时表达嗜碱小杆菌SK51.001的环糊精葡聚糖转移酶(CGTase)和球形芽孢杆菌E-244的环麦芽糖糊精酶(CDase)这两种酶的基因工程菌株。Escherichia coli BL21(DE3) ( E.coli ) 菌株产生含有载体 pETDuet- Ga CGT/ Bs CD (p GaBs ) 的重组细胞）。这些细胞被用作从廉价底物（淀粉）生物转化 G7 的全细胞催化剂。由于淀粉的高分子量，细胞膜阻止淀粉进入细胞系统。因此，p GaBs细胞壁被溶菌酶、EDTA 和热处理透化。在达到透化p GaBs细胞量、溶菌酶量、反应温度和金属离子浓度的优化条件后，加入Ca 2+，30 g/L淀粉在1 h内可产生约4.1 g/L G7 。这种共表达系统提供了一种使用廉价底物生产

  DOI：

  10.1016/j.enzmictec.2022.110057

文献信息

• Biomimetic Reagents for the Selective Free Radical and Acid–Base Chemistry of Glycans: Application to Glycan Structure Determination by Mass Spectrometry
  作者：Jinshan Gao、Daniel A. Thomas、Chang Ho Sohn、J. L. Beauchamp

  DOI：10.1021/ja402810t

  日期：2013.7.24

  susceptible to dissociation by free radicals, mainly reactive oxygen species, which inspired our development of a free radical activated glycan sequencing (FRAGS) reagent, which combines a free radical precursor with a pyridine moiety that can be coupled to the reducing terminus of target glycans. Collisional activation of FRAGS-derivatized glycans generates a free radical that reacts to yield abundant

  大自然擅长将聚糖分解成它们的成分，通常是通过酶促酸碱催化来实现糖苷键的选择性裂解。注意到质子转移在许多这些酶的活性位点中的重要性，我们描述了一种用于酸催化聚糖测序 (PRAGS) 的隔离质子试剂，该试剂使用具有中等质子亲和力的吡啶部分衍生化聚糖的还原末端。PRAGS 衍生聚糖的气相碰撞活化主要产生 C1-O 糖苷键裂解，保留还原末端的电荷。可以分析由此产生的系统性 PRAGS 指导的聚糖解构，以提取聚糖组成和序列。聚糖也很容易被自由基解离，主要是活性氧，这启发了我们开发自由基活化聚糖测序 (FRAGS) 试剂，该试剂将自由基前体与吡啶部分结合，可与目标聚糖的还原末端偶联。FRAGS 衍生聚糖的碰撞活化产生自由基，该自由基反应产生大量交叉环裂解、糖苷键裂解以及这些类型裂解的组合，并在还原端保留电荷。使用 FRAGS 试剂通过仅在这些位置观察到的特定碎片模式来识别分支位点。研究和讨论了解离机制
• Gluco-oligomers initially formed by the reuteransucrase enzyme of Lactobacillus reuteri 121 incubated with sucrose and malto-oligosaccharides
  作者：Justyna M Dobruchowska、Xiangfeng Meng、Hans Leemhuis、Gerrit J Gerwig、Lubbert Dijkhuizen、Johannis P Kamerling

  DOI：10.1093/glycob/cwt048

  日期：2013.9

  The probiotic bacterium Lactobacillus reuteri 121 produces a complex, branched (1 → 4, 1 → 6)-α-d-glucan as extracellular polysaccharide (reuteran) from sucrose (Suc), using a single glucansucrase/glucosyltransferase (GTFA) enzyme (reuteransucrase). To gain insight into the reaction/product specificity of the GTFA enzyme and the mechanism of reuteran formation, incubations with Suc and/or a series of malto-oligosaccharides (MOSs) (degree of polymerization (DP2–DP6)) were followed in time. The structures of the initially formed products, isolated via high-performance anion-exchange chromatography, were analyzed by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry and 1D/2D 1H/13C NMR spectroscopy. Incubations with Suc only, acting as both donor and acceptor, resulted in elongation of Suc with glucose (Glc) units via alternating (α1 → 4) and (α1 → 6) linkages, yielding linear gluco-oligosaccharides up to at least DP ∼ 12. Simultaneously with the ensemble of oligosaccharides, polymeric material was formed early on, suggesting that alternan fragments longer than DP ∼ 12 have higher affinity with the GTFA enzyme and are quickly extended, yielding high-molecular-mass branched reuteran (4 × 107 Da). MOSs (DP2–DP6) in the absence of Suc turned out to be poor substrates. Incubations of GTFA with Suc plus MOSs as substrates resulted in preferential elongation of MOSs (acceptors) with Glc units from Suc (donor). This apparently reflects the higher affinity of GTFA for MOSs compared with Suc. In accordance with the GTFA specificity, most prominent products were oligosaccharides with an (α1 → 4)/(α1 → 6) alternating structure.

  益生菌吕特氏乳杆菌（Lactobacillus reuteri）121利用一种单一的葡聚糖琥珀酸酶/葡糖基转移酶（GTFA）（reuteransucrase），从蔗糖（Suc）中产生一种复杂的支链（1→4，1→6）-α-d-葡聚糖作为胞外多糖（reuteran）。为了深入了解 GTFA 酶的反应/产物特异性和芦丁聚糖的形成机制，对 Suc 和/或一系列麦芽寡糖（MOS）（聚合度为 DP2-DP6）的孵育过程进行了及时跟踪。最初形成的产物通过高效阴离子交换色谱法分离出来，并通过基质辅助激光解吸电离飞行时间质谱法和 1D/2D 1H/13C NMR 光谱法分析其结构。在同时作为供体和受体的 Suc 诱导下，Suc 通过交替 (α1 → 4) 和 (α1 → 6) 连接与葡萄糖（Glc）单元发生伸长，产生线性葡萄糖寡糖，至少达到 DP ∼ 12。在低聚糖集合的同时，很早就形成了聚合物质，这表明长于 DP ∼ 12 的交替聚糖片段与 GTFA 酶的亲和力较高，并能迅速延伸，产生高分子质量的支链芦丁聚糖（4 × 107 Da）。在没有 Suc 的情况下，MOSs（DP2-DP6）是较差的底物。将 GTFA 与作为底物的 Suc 和 MOS 一起培养，结果是 MOS（接受者）优先与来自 Suc（供体）的 Glc 单位发生延伸。这显然反映出与 Suc 相比，GTFA 对 MOS 的亲和力更高。根据 GTFA 的特异性，最主要的产物是具有（α1 → 4）/（α1 → 6）交替结构的寡糖。
• Fluorinated Carbon Tag Derivatization Combined with Fluorous Solid-Phase Extraction: A New Method for the Highly Sensitive and Selective Mass Spectrometric Analysis of Glycans
  作者：Lulu Li、Jing Jiao、Yan Cai、Ying Zhang、Haojie Lu

  DOI：10.1021/ac504437h

  日期：2015.5.19

  The sensitive and specific detection of glycans via mass spectrometry (MS) remains a significant challenge due to their low abundance in complex biological mixtures, inherent lack of hydrophobicity, and suppression by other, more abundant biological molecules (proteins/peptides) or contaminants. A new strategy for the sensitive and selective MS analysis of glycans based on fluorous chemistry is reported. Glycan reducing ends were derivatized with a hydrophobic fluorinated carbon tag, increasing glycan ionization efficiency during MS by more than an order of magnitude. More importantly, the fluorinated carbon tag enabled efficient fluorous solid-phase extraction (FSPE) to specifically enrich the glycans from contaminated solutions and protein mixtures. Finally, we successfully analyzed the N-glycome in human serum using this new method.

  由于聚糖在复杂的生物混合物中含量较低，本身缺乏疏水性，并且受到其他含量更高的生物分子（蛋白质/肽）或污染物的抑制，因此通过质谱（MS）灵敏而特异地检测聚糖仍然是一项重大挑战。本文报告了一种基于氟化学的灵敏、选择性质谱分析聚糖的新策略。利用疏水性氟化碳标签对聚糖还原端进行衍生，可将质谱分析中的聚糖电离效率提高一个数量级以上。更重要的是，氟化碳标签使高效的流体固相萃取（FSPE）成为可能，从而从受污染的溶液和蛋白质混合物中特异性地富集聚糖。最后，我们利用这种新方法成功分析了人血清中的 N-糖蛋白。
• Maltose/Maltodextrin System of<i>Escherichia coli</i>: Transport, Metabolism, and Regulation
  作者：Winfried Boos、Howard Shuman

  DOI：10.1128/mmbr.62.1.204-229.1998

  日期：1998.3

  The maltose system of Escherichia coli offers an unusually rich set of enzymes, transporters, and regulators as objects of study. This system is responsible for the uptake and metabolism of glucose polymers (maltodextrins), which must be a preferred class of nutrients for E. coli in both mammalian hosts and in the environment. Because the metabolism of glucose polymers must be coordinated with both the anabolic and catabolic uses of glucose and glycogen, an intricate set of regulatory mechanisms controls the expression of mal genes, the activity of the maltose transporter, and the activities of the maltose/maltodextrin catabolic enzymes. The ease of isolating many of the mal gene products has contributed greatly to the understanding of the structures and functions of several classes of proteins. Not only was the outer membrane maltoporin, LamB, or the phage lambda receptor, the first virus receptor to be isolated, but also its three-dimensional structure, together with extensive knowledge of functional sites for ligand binding as well as for phage λ binding, has led to a relatively complete description of this sugar-specific aqueous channel. The periplasmic maltose binding protein (MBP) has been studied with respect to its role in both maltose transport and maltose taxis. Again, the combination of structural and functional information has led to a significant understanding of how this soluble receptor participates in signaling the presence of sugar to the chemosensory apparatus as well as how it participates in sugar transport. The maltose transporter belongs to the ATP binding cassette family, and although its structure is not yet known at atomic resolution, there is some insight into the structures of several functional sites, including those that are involved in interactions with MBP and recognition of substrates and ATP. A particularly astonishing discovery is the direct participation of the transporter in transcriptional control of the mal regulon. The MalT protein activates transcription at all mal promoters. A subset also requires the cyclic AMP receptor protein for transcription. The MalT protein requires maltotriose and ATP as ligands for binding to a dodecanucleotide MalT box that appears in multiple copies upstream of all mal promoters. Recent data indicate that the ATP binding cassette transporter subunit MalK can directly inhibit MalT when the transporter is inactive due to the absence of substrate. Despite this wealth of knowledge, there are still basic issues that require clarification concerning the mechanism of MalT-mediated activation, repression by the transporter, biosynthesis and assembly of the outer membrane and inner membrane transporter proteins, and interrelationships between the mal enzymes and those of glucose and glycogen metabolism.

  摘要大肠杆菌的麦芽糖系统提供了一套异常丰富的酶、转运体和调节器作为研究对象。该系统负责葡萄糖聚合物（麦芽糊精）的吸收和新陈代谢，而葡萄糖聚合物肯定是哺乳动物宿主和环境中大肠杆菌的首选营养物质。由于葡萄糖聚合物的新陈代谢必须与葡萄糖和糖原的合成代谢和分解代谢协调进行，因此有一套复杂的调节机制控制着 mal 基因的表达、麦芽糖转运体的活性以及麦芽糖/麦芽糊精分解代谢酶的活性。由于很容易分离出许多 mal 基因产物，这大大有助于人们了解几类蛋白质的结构和功能。外膜麦芽糖糊精受体 LamB（噬菌体λ受体）不仅是第一个被分离出来的病毒受体，而且其三维结构以及配体结合和噬菌体λ结合功能位点的广泛知识，使人们对这种糖特异性水通道有了相对完整的描述。我们还研究了质外麦芽糖结合蛋白（MBP）在麦芽糖转运和麦芽糖分类中的作用。同样，结构和功能信息的结合使人们对这种可溶性受体如何参与向化学感受器发出糖存在的信号以及如何参与糖转运有了重要的了解。麦芽糖转运体属于 ATP 结合盒家族，尽管其结构尚未达到原子分辨率，但人们对其几个功能位点的结构有了一些了解，包括那些参与与 MBP 相互作用以及识别底物和 ATP 的位点。一个特别惊人的发现是，转运体直接参与了 mal 调节子的转录控制。MalT 蛋白可激活所有 mal 启动子的转录。一个子集的转录还需要环 AMP 受体蛋白。MalT 蛋白需要麦芽三糖和 ATP 作为配体，才能与十二核苷酸的 MalT 框结合。最新数据表明，当转运体因缺乏底物而失去活性时，ATP 结合盒转运体亚基 MalK 可直接抑制 MalT。尽管有了这些丰富的知识，但在 MalT 介导的激活机制、转运体的抑制、外膜和内膜转运蛋白的生物合成和组装以及 mal 酶与葡萄糖和糖原代谢酶之间的相互关系等方面，仍有一些基本问题需要澄清。
• Characterization and mechanism of action of Microbacterium imperiale glucan 1,4-α-maltotriohydrolase
  作者：Chunsen Wu、Xing Zhou、Yan Xu、Hongyan Li、Yaoqi Tian、Xueming Xu、Zhengyu Jin

  DOI：10.1016/j.carres.2013.11.014

  日期：2014.1

  In this study, glucan 1,4-alpha-maltotriohydrolase (AMTS) from Microbacterium imperiale was purified and characterized. Hydrolysis by AMTS was affected by starch structure (e. g., amylose versus amylopectin) and hydrolysis time. During the initial phase of hydrolysis of maltooligosaccharides (G4-G7), AMTS displayed a unique transfer specificity to the transfer of maltotriosyl units. After extensive hydrolysis, maltotriose became the major end product, followed by glucose and maltose. Maltotetraose (G4) was the smallest donor in transglycosylation reactions by AMTS. This is the first study that reports transglycosylation activity of AMTS on maltooligosaccharides. The results of this study suggest that high purity maltotriose can be produced by the hydrolytic action of AMTS on starch. (C) 2013 Elsevier Ltd. All rights reserved.