Athens variant of glucose-6-phosphate dehydrogenase

A variant of glucose-6-phosphate dehydrogenase (G6PD), characterized by slower than normal electrophoretic migration and associated with mild deficiency of G6PD in the red cells, was detected in two unrelated Greek males. Electrophoretic, chromatographic, and enzymologic study indicated that the new mutant is structurally different from normal G6PD (B+) and from the Mediterranean variant associated with red-cell enzyme deficiency (B-). Convincing electrophoretic separation of the new variant from the normal B+ and the Mediterranean B- enzymes was achieved only by detailed electrophoretic study in different buffer systems and conditions.     

Glucose-6-phosphatase and the exchange of glucose with glucose-6-phosphate

An equation is presented which makes it possible to estimate the exchange activity of glucose-6-phosphatase, as a percentage of the hydrolytic activity, for a given concentration of substrate and acceptor. The quantitative significance of the exchange-inhibition phenomenon is discussed.     

Erythrocyte acid phosphomonesterase and glucose-6-phosphate dehydrogenase deficiency in Caucasians

Caucasian patients with erythrocyte glucose-6-phosphate dehydrogenase deficiency also have a deficiency in erythrocyte acid phosphomonoesterase. This acid phosphomonoesterase deficiency is not present in Negroes with the glucose-6-phosphate dehydrogenase deficiency.     

Sex-linkage of erythrocyte glucose-6-phosphate dehydrogenase in two species of wild hares

Glucose-6-phosphate dehydrogenase specific to the erythrocytes of each of two wild hares found in Europe was discerned by starch-gel electrophoresis at pH 7.0 and pH 8.6. The single, sharp band of the dehydrogenase of Lepus europaeus was faster than that of L. timidus, at both pH levels. The sex-linkage of this enzyme was tested through reciprocal hybrids between the two species. Each male hybrid had a single band of enzyme identical with that of its mother, while both parental types of this enzyme coexisted in female hybrids. Thus, sex-linkage of glucose-6-phosphate dehydrogenase has been suggested not only in man and in the family Equidae, but now in the family Leporidae of placental mammals as well.     

松墨天牛葡萄糖-6-磷酸异构酶基因克隆及序列分析

[目的]克隆松墨天牛(Monochamus alteratus)葡萄糖-6-磷酸异构酶(GPI)基因cDNA序列,探究其分子特征,为深入研究松墨天牛GPI的分子功能打下基础.[方法]采用RACE技术克隆松墨天牛GP基因cDNA序列,并对该序列及其编码氨基酸序列进行生物信息学分析.[结果]克隆并鉴定松墨天牛GPI基因,命名为MaGPI(GenBank登录号:KU323592),该基因序列长1038bp,共编码279个氨基酸.同源比对分析发现,松墨天牛与赤拟谷盗(Tribolium castaneum)的同源性最高,达90%,而与其他昆虫的同源性在76%以上.系统发育进化树分析结果表明,松墨天牛与赤拟谷盗在同一分支,与家蚕(Bombyx mori)相隔最远.MaGPI为亲水蛋白,含有5个功能位点:活性位点、变构位点、活性部位盖子和两个多肽结合位点.[结论]明确了MaGPI的核苷酸序列及编码蛋白特征,为进一步研究MaGPI的分子功能提供依据.     

Alpha-glycerophosphate dehydrogenase and glucose-6-phosphate dehydrogenase in tissues of the Weddell seal

High activity of alpha-glycerophosphate dehydrogenase and low activity of glucose-6-phosphate dehydrogenase in adipose tissue of Weddell seals suggest that neutral fat may be assembled there from exogenous sources of fatty acids. Low activity of glucose-6-phosphate dehydrogenase in other tissues tested precludes assignment of the function of fatty-acid synthesis to any specific tissue and emphasizes uniqueness of adipose mass in seals.     

Negro variant of glucose-6-phosphate dehydrogenase deficiency (A-) in man

Glucose-6-phosphate dehydrogenase in erythrocytes of the Negro type associated with enzyme deficiency (A(-)) was separated by chromatography on a carboxymethyl-Sephadex column from the electrophoretically indistinguishable Negro variant with normal enzyme activity (A(+)). Quantitative immunologic neutralization tests indicated that the A(-) enzyme had about the same enzymatic and serological activity as the A(+) and the normal (B(+)) enzymes. The enzyme activity of the A(-) variant in young erythrocytes was similar to that in young cells from normal individuals, although the activity of the A(-) variant in unfractionated red cells was 10 to 15 percent of normal. These data indicate that the basic defect in the variant enzyme (A(-)) is a structural mutation which causes more rapid degradation of the enzyme during erythrocyte aging.     

巨细胞病毒DNA和葡萄糖-6-磷酸脱氢酶对新生儿高胆红素血症的诊断意义

目的 分析巨细胞病毒(CMV)-DNA和葡萄糖-6-磷酸脱氢酶(G6PD)水平对新生儿高胆红素血症的诊断意义.方法 选取该院高胆红素血症新生儿作为观察组(n=196),另选取同期新生儿作为对照组(n=100),分别采用FQ-PCR技术与生化法检测两组母乳、新生儿尿液CMV-DNA和血清G6PD水平.绘制ROC曲线,比较...     

Air lead: relation to lead in blood of black school children deficient in glucose-6-phosphate dehydrogenase

Forty-four black children at two elementary schools within 0.7 mile of a battery plant had significantly higher (P < .001) concentrations of lead in their bloods (34.1 +/- 9.7, micrograms per 100 milliliters, mean +/- standard deviation) than 122 students (26.3 +/- 7.1) at seven schools 1 to 3 miles distant; 5 months later there was a comparable difference between red cell lead values (54.1 +/- 18.5 versus 37.4 +/- 12.6). Among the blacks, those deficient in glucose-6-phosphate dehydro-genase had a higher (P < .005) concentration of lead in the blood after correction for anemia (32.9 +/- 9.7) than the nondeficient (25.7 +/- 8.8), and a higher concentration in the red cells (47.3 +/- 14.7 as compared to 35.6 +/- 15.8, P < .001); the enzyme effect was independent of geographic location.     

全自动换血治疗G-6-PD缺陷症并发急性溶血的疗效观察

目的 :观察全自动换血治疗危重G 6 PD缺陷症并发急性溶血的疗效。方法 :对 1 0例危重G 6 PD缺陷症并发急性溶血采用全自动换血治疗。结果 :总胆红素由换血前 (5 33.1 4± 1 1 5 .6 5 ) μmol/L下降至换血后 (2 95 .5 0± 88.5 1 )μmol/L ,换出率是 4 4 .5 7% ,血红蛋白增加 34.1 2 % ,红细胞增加 4 3.30 % ,换血过程无明显不良反应。结论 :全自动换血是抢救危重G 6 PD缺陷症并发急性溶血的简单、实用、安全、有效的方法     

甜瓜属野生种Cucumis hystrix Chakr.胞质葡萄糖-6-磷酸脱氢酶基因的克隆与启动子结构分析

根据植物葡萄糖-6-磷酸脱氢酶(G6PDH,EC1.1.1.49)氨基酸保守区域,设计简并引物,采用RT-PCR技术克隆得到甜瓜属野生种Cucumis hystrix Chakr.(2n=24)G6PDH基因cDNA片段;随后基于该序列设计特异引物,PCR方法筛选野生种BAC文库,获得2个BAC阳性单克隆。测序后获得了G6PDH基因全序列及其上游启动子序列,GenBank登录号:JQ771576。序列分析显示:G6PDH基因全长约6.5 kb,由15个外显子和14个内含子组成;内含子序列均符合5’-gt-ag-3’结构。外显子拼接后获得了G6PDH基因的开放阅读框(ORF)序列,序列全长1 551 bp,编码516个氨基酸,与黄瓜基因组网站公布的G6PDH基因核苷酸序列和氨基酸序列同源性分别为98.71%和99.03%。野生种G6PDH氨基酸序列N端缺少转运肽序列,确定为野生种胞质G6PDH。氨基酸序列与烟草、马铃薯、荷兰芹、猕猴桃、拟南芥、大豆、小麦、玉米、葡萄、杨树等植物胞质G6PDH同源性高达77%以上。系统发育树分析发现,甜瓜属胞质G6PDH与茄科植物最先聚类,植物胞质G6PDH在分子进化水平上与物种进化相符。启动子结构分析表明:序列含有启动子基本元件TATA-box、CAAT-box,还含有丰富的光响应元件,与环境胁迫响应相关的不同顺式作用元件,促进高水平转录的5UTR Py-rich stretch元件和提高表达的CAT-box元件等。     

Glucose-6-phosphate dehydrogenase and detoxification of hydrogen peroxide in human erythrocytes

Human erythrocytes with deficient glucose-6-phosphate dehydrogenase levels are unable to maintain their levels of reduced glutathione in the presence of low-level, steady-state concentrations of hydrogen peroxide. This finding has bearing on the biochemical mechanisms of drug-induced hemolytic anemia.     

海藻糖的应用及其合酶基因TPS在植物转基因中的研究进展

海藻糖是一种非还原性双糖,具有很高的稳定性和很强的吸水性等性质,能够提高生物体对各种非生物胁迫的抵抗能力.目前有很多研究表明通过转化海藻糖合酶基因增加体内海藻糖含量可能成为选育作物抗逆品种的新方法.该文对海藻糖的理化性质、生物学特性及其应用情况作了简要的概述,并介绍了编码酵母海藻糖合酶复合体基因的组成以及各个组成基因的功能,着重阐述了海藻糖合酶基因在植物转基因方面(尤其在提高植物抗逆性)的研究进展.     

二色补血草海藻糖-6-磷酸磷酸酯酶基因的克隆及分析

以二色补血草叶片组织为材料构建了cDNA文库,文库的初始滴度为2.0×106pfu,重组率为95%,平均插入片段为0.8 kb,扩增后文库的滴度为4.0×109pfu.mL-1。通过随机测序从文库中获得的海藻糖-6-磷酸磷酸酯酶(trehalose-6-phosphate phosphatase,TPP)基因的全长cDNA序列,该序列长1 986 bp,其中5’非翻译区163 bp,3’非翻译区680 bp,开放读码框长1 143 bp,编码380个氨基酸,蛋白分子质量为42KD,理论等电点为6.68。海藻糖-6-磷酸磷酸酯酶在海藻糖合成过程中起关键作用,该基因的克隆为研究海藻糖在二色补血草中的合成奠定了基础。     

Structural basis of glmS ribozyme activation by glucosamine-6-phosphate

The glmS ribozyme is the only natural catalytic RNA known to require a small-molecule activator for catalysis. This catalytic RNA functions as a riboswitch, with activator-dependent RNA cleavage regulating glmS messenger RNA expression. We report crystal structures of the glmS ribozyme in precleavage states that are unliganded or bound to the competitive inhibitor glucose-6-phosphate and in the postcleavage state. All structures superimpose closely, revealing a remarkably rigid RNA that contains a preformed active and coenzyme-binding site. Unlike other riboswitches, the glmS ribozyme binds its activator in an open, solvent-accessible pocket. Our structures suggest that the amine group of the glmS ribozyme-bound coenzyme performs general acid-base and electrostatic catalysis.     

Sorting of mannose 6-phosphate receptors mediated by the GGAs

The delivery of soluble hydrolases to lysosomes is mediated by the cation-independent and cation-dependent mannose 6-phosphate receptors. The cytosolic tails of both receptors contain acidic-cluster-dileucine signals that direct sorting from the trans-Golgi network to the endosomal-lysosomal system. We found that these signals bind to the VHS domain of the Golgi-localized, gamma-ear-containing, ARF-binding proteins (GGAs). The receptors and the GGAs left the trans-Golgi network on the same tubulo-vesicular carriers. A dominant-negative GGA mutant blocked exit of the receptors from the trans-Golgi network. Thus, the GGAs appear to mediate sorting of the mannose 6-phosphate receptors at the trans-Golgi network.     

Stretch receptors in the foregut of the blowfly

Two bipolar neurons are located in a nerve branch connecting the recurrent nerve and foregut of the blowfly Phormia regina. Spike activity accompanying peristalsis or controlled enlargement of the foregut region is recorded from two cells in the recurrent nerve. The spikes are abolished by section of the nerve branch connecting recurrent nerve and foregut. It is concluded that the two neurons are the foregut stretch receptors predicted from results of behavioral experiments and vital to the regulation of feeding by the fly.