Dextransucrase: donor substrate reactions.
Dextransucrase: donor substrate reactions.
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葡聚糖蔗糖酶：供体底物反应。
DOI：
10.1016/0003-9861(81)90151-x
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发表时间：
1981
影响因子：
3.9
通讯作者：
Mayer,RM
中科院分区：
文献类型：
--
作者：
Jung,SM;Mayer,RM
先前的研究表明，α-d-1-氟葡萄糖是葡萄糖基转移酶的糖基供体（5，6），包括由明串珠菌和变形链球菌形成的葡聚糖蔗糖酶。本报告证实了这些观察与葡聚糖蔗糖酶分离S。Sanguisand最终确定了该反应的细节，并证明氟葡萄糖转移的机理与蔗糖的葡萄糖基转移相当。一个新的程序用于监测反应的报道，是基于质子形成的测量使用的pH指示剂，溴甲酚紫。发现F−的产生与质子的产生是化学计量的。底物速率研究表明，α-1-氟葡萄糖发生自发水解，在亲核缓冲液存在下大大增加。当[14 C]麦芽糖和α-1-氟葡萄糖或[14 C]α-1-氟葡萄糖和麦芽糖与葡聚糖蔗糖酶孵育时，观察到一系列寡糖产物。结果表明，α-1-氟葡萄糖的葡萄糖基部分转移到受体上。产物形成的性质与一系列的底物-产物反应一致。通过硼氢化物还原分析的产物分析表明，葡萄糖基单元被添加到麦芽糖的非还原端。当[14 C]果糖或[14 C]-α-1-氟葡萄糖与酶一起孵育时，观察到的反应类似于在[14 C]果糖和蔗糖存在下由酶催化的同位素交换反应。
Previous studies have indicated that α-d-1-fluoroglucose is a glycosyl donor for glucosyl transferases (5, 6) including dextransucrases formed byLeuconostocandStreptococcus mutans. The present report confirms these observations with dextransucrase isolated fromS. sanguisand conclusively establishes the details of this reaction as well as proving that mechanism of fluoroglucose transfer is comparable to that glucosyl transfer from sucrose. A new procedure for monitoring the reaction is reported, and is based on the measurement of proton formation using the pH indicator, bromcresol purple. Production of F−was found to be stoichiometric with proton production. Rate studies with the substrate indicate that α-1-fluoroglucose undergoes spontaneous hydrolysis, which is greatly increased in the presence of nucleophilic buffers. When [14C]maltose and α-1-fluoroglucose or [14C]α-1-fluoroglucose and maltose were incubated with dextransucrase, a series of oligosaccharide products was observed. The results indicate that the glucosyl moiety of α-1-fluoroglucose transferred to the acceptor. The nature of formation of the products are consistent with a series of precursor-product reactions. Product analysis of the saccharides by borohydride reduction analysis demonstrated that the glucosyl unit was added to the nonreducing end of maltose. When either [14C]fructose or [14C]-α-1-fluoroglucose were incubated with enzyme, a reaction was observed which was analogous to the isotopic-exchange reaction catalyzed by the enzyme in the presence of [14C]fructose and sucrose.
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由于肌间神经丛中嗜银神经元缺乏而导致功能性肠梗阻。
影响因子：
5.2
作者：
M. Tanner;B. Smith;J. Lloyd
通讯作者：
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DOI：
--
发表时间：
1980
期刊：
Memórias do Instituto Oswaldo Cruz
影响因子：
--
作者：
M. Teixeira;Jofre Rezende Filho;Florêncio Figueredo;A. Teixeira
通讯作者：
A. Teixeira
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DOI：
--
发表时间：
1980
期刊：
Revue neurologique (Paris)
影响因子：
--
作者：
F. Lhermitte;F. Gray;O. Lyon‐Caen;B. Pertuiset;P. Bernard
通讯作者：
P. Bernard
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影响因子：
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作者：
Schuffler,MD;Jonak,Z
通讯作者：
Jonak,Z
确定哺乳动物神经元和克氏锥虫寄生虫亚群抗原决定簇的单克隆抗体
影响因子：
64.8
作者：
J. Wood;L. Hudson;T. M. Jessell;T. M. Jessell;Masayuki Yamamoto;Masayuki Yamamoto
通讯作者：
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