不同类型大豆同工酶的研究

本文系用聚丙烯酰胺凝胶垂直平板电泳方法对不同纬度的野生、半野生及栽培大豆的苹果酸脱氢酶、酸性磷酸酯酶同工酶进行了研究,提出大豆同工酶模式酶谱。G.soja 亚属大豆苹果酸脱氢酶共有6条酶带,酸性磷酸酯酶共有12条酶带。所有材料都出现苹果酸脱氢酶Ⅳ带,反映了遗传的同源性,并可作为 G.soja 亚属大豆的共同酶带。种间酶带出现频率和相对含量分析表明,半野生大豆处于野生大豆和栽培大豆中间,栽培大豆系由野生大豆经过中间类型进化而来。在进化过程中既有原酶带缺失又有新酶带产生,苹果酸脱氢酶Ⅳ带,酸性磷酸酯酶Ⅶ、Ⅷ、Ⅸ带平均相对含量在30°—35°N 最高,说明与地理分布有关。     

Human-mouse somatic cell hybrids with single human chromosome (group E): link with thymidine kinase activity

Mouse somatic cells lacking thymidine kinase were mixed in culture with human diploid cells lacking hypoxanthine guanine phosphoribosyl transferase, and hybrid cells were isolated and maintained in a selective medium containing hypoxanthine, aminopterin, and thymidine. The hybrid cells at the time of isolation had karyotypes consisting predominantly of mouse chromosomes but with one human chromosome, a submetacentric member of group E, apparently giving thymidine kinase to the hybrid cell. However, after long-term propagation in the selective medium this chromosome has been lost, although cells continue to show thymidine kinase activity as demonstrated by the incorporation of (3)H-thy-midine into DNA in the hybrid cell. The hybrid cells have only mouse electro-phoretic variants for glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and malate dehydrogenase, suggesting that the human genetic loci for these enzymes are not represented in the hybrid genome and may be unlinked to that for thymidine kinase.     

Two c-type cytochromes from light- and dark-grown Euglena

A pigment-protein complex can be extracted, in aqueous 2-percent digitonin, from Euglena grown in the light. When further fractionated by acetone and ammonium sulfate this flagellate yields a c-type cytochrome. By similar extraction of dark-grown, nonphotosynthetic Euglena, another c-type cytochrome can be isolated. The cytochrome from the light-grown Euglena- is like that of cytochrome c isolated from a photosynthetic bacterium. The cytochrome from the dark-grown Euglena is like cytochrome f found in the chloroplasts of higher plants.     

团头鲂乳酸脱氢酶与苹果酸脱氢酶组织特异性的激光扫描分析

用LKB水平电泳仪,4.4%聚丙烯酰胺凝胶,对10—11月龄团头鲂(全长14—16cm)的11种组织——白肌、晶体、脑、脾、肾、性腺、心、肝、鳍、红血球及血清的乳酸脱氢酶和苹果酸脱氢酶作电泳,再用LKB激光光密度计对同工酶的迁移率及活性作定性定量分析。在不同组织中,同工酶的迁移率和活性有明显的组织特异性。     

鸡肝NADPH生成酶与腹脂关系的研究

利用育成的黄羽鸡新扬州鸡，研究了鸡肝内ＮＡＤＰＨ生成酶与腹脂、屠体性状的关系，结果表明，１７周龄３种ＮＡＤＰＨ生成酶中，苹果酸脱氢酶（ＭＤ）活性最高，６－磷酸葡萄糖脱氢酶（ＧＰ）次之，异柠檬酸脱氢酶（ＩＳ）最小。苹果酸脱氢酶可能是脂肪合成过程中提供氢的最主要的酶，３种酶与腹脂重、腹脂率均呈正相关，与屠体性状呈正或负的弱相关，说明３种ＮＡＤＰＨ生成酶活性低时，鸡的腹脂重（率）降低，产肉性能提高，表明此酶的活性有可能作为选择低脂以鸡的辅助手段     

长白松自然群体同功酶遗传多样性的研究

本文以酶水平,研究了两个自然群体的遗传多样性。采用聚丙烯酰胺凝胶电泳技术,检测了长白松雌配子体的谷氨酸草酰乙酸转氨酶(GDT),苹果酸脱氢酶(MDT),酸性磷酸酶(ACP),谷氨酸脱氢酶(GDH)和葡萄糖脱氢酶(GLUDH)的同功酶型。根据多态基因位点标准,笔者发现检测基因位点的63％是多态的。8个基因位点所有样品的杂合性的平均值是0.3157。每个基因位点的平均等位基因数是2.19。两个自然群体间的同功酶多样性分化,对8个基因位点的基因多样性测量表明,群体间基因多样性的分化明显效果是9％,总的基因多样性的91％在群体内。两个群体间的遗传距离是0.0619。     

A specific, highly active malate dehydrogenase by redesign of a lactate dehydrogenase framework

Three variations to the structure of the nicotinamide adenine dinucleotide (NAD)-dependent L-lactate dehydrogenase from Bacillus stearothermophilus were made to try to change the substrate specificity from lactate to malate: Asp197----Asn, Thr246----Gly, and Gln102----Arg). Each modification shifts the specificity from lactate to malate, although only the last (Gln102----Arg) provides an effective and highly specific catalyst for the new substrate. This synthetic enzyme has a ratio of catalytic rate (kcat) to Michaelis constant (Km) for oxaloacetate of 4.2 x 10(6)M-1 s-1, equal to that of native lactate dehydrogenase for its natural substrate, pyruvate, and a maximum velocity (250 s-1), which is double that reported for a natural malate dehydrogenase from B. stearothermophilus.     

异色瓢虫鞘翅色斑型间的四种同工酶比较研究

应用聚丙聚酰胺凝胶电泳比较了异色瓢虫不同鞘翅色斑型成虫的四种同工酶谱和不同色斑型间杂交后代幼期的酯酶同工酶酶谱。结果表明：除苹果酸酶同工酶外，各色斑型成虫间酯酶、苹果酸脱氢酶和过氧化物酶的同工酶带数、活性均有差异。异色瓢虫不同色斑型的杂交后代，在幼期不同发育阶段的个体，其酯酶同工酶带数、活性有较大差异，但同一发育阶段的个体，其酯酶同工酶没有差别。     

耐酸性紫花苜蓿的研究进展*

 紫花苜蓿要在占到世界可耕地面积的40%的酸性土壤上推广和利用，就必须培育耐酸性品种。现已获得的转基因苜蓿在耐酸性和耐铝性方面都有了很大的提高。主要是通过导入特定花椰菜花叶病毒35S作为启动子，引起苹果酸脱氢酶（MDH）和烯醇式丙酮酸羧化酶（PEPC）超表达，结果表明与非转基因苜蓿相比较，MDH的量增加1.6倍时，转基因苜蓿根尖有机酸的浓度增加了4.2倍，而柠檬酸、草酸、苹果酸、琥珀酸和醋酸在根部的分泌量增加了7.1倍；但是PEPC的超表达对增加苜蓿根部有机酸的分泌没有贡献。通过转基因苜蓿根际周围增加的有机酸来螫合铝元素，从而减轻酸性土壤中铝毒对苜蓿生产的限制。     

Lactate dehydrogenase isozymes: further kinetic studies at high enzyme concentration

By competition with lactate dehydrogenase (LDH) for nicotinamide adenine dinucleotide (NAD), commonly occurring intracellular proteins, such as glyceraldehyde-3-phosphate dehydrogenase, malate dehydrogenase, and albumin, can protect LDH-1 and LDH-5 from inhibition and ternary complex formation with NAD and pyruvate. The existence of intracellular proteins that compete with LDH for NAD renders unphysiological a model for estimating the extent of intracellular LDH inhibition based on incubations of only LDH, NAD, and pyruvate.     

甘蔗12个种和品种的6种同工酶比较

用聚丙烯酰胺垂直平板电泳法,在甘蔗个体发育过程中,分离鉴定了十二个供试材料叶片的六种同工酶。结果表明:甘蔗种问和品种间酶谱存在差异,酶谱在个体发育过程中有变化,其程度因酶的种类和供试材料而异。苗期过氧化物酶Ⅱ区的总酶带数与丛茎数呈极显著正相关。与茎径呈显著负相关;分蘖末期该酶Ⅱ区的总酶带数与丛茎数亦呈极显著正相关,与茎径呈负相关,但不显著;其强带数则与两者都呈显著相关。其余五种酶的酶谱未发现与所调查的农艺性状有明显规律的联系。最后讨论了上述结果在甘蔗选育种和栽培中的应用。     

58个香菇菌株的酶谱分析及其鉴别

应用浆丙烯酰胺凝胶电泳技术分析了58个不同来源的香菇(Lentinusedodes)菌株的酯酶,根据分析结果,可区分为28个类型。并对其中3种香菇菌株的不同培养菌龄的酯酶加以分析,获得了条带位置相同,而条带强弱不同的酶谱;同时分析了其中13个菌酶的苹果酸脱氢酶,谷氨酸脱氢酶以及乙醇脱氢酶。根据苹果酸脱氢酶的酶谱,可分6个类型,谷氯酸脱氢酶以及乙醇脱氢酶条带较少,各分成两个类型。对其中两种香菇菌株的单核丝及其双核菌丝的4种酶谱作了比较。酯酶变化差异较大,对于香菇菌株的早期鉴别,是一种稳定、有效、简便的方法,而苹果酸脱氢酶以及谷氨酸脱氲酶、乙醇脱氢酶,除少数菌株之外,未表现出特殊的差异。     

Esterase, malate, and lactate dehydrogenases activity in murine neuroblastoma

Mouse neuroblastoma tumors have only the fifth isozyme band (A(4)) of lactate dehydrogenase, whereas this band is missing in the brain which contained four other bands of lactate dehydrogenase. The alpha-esterase isozyme patterns of tumors, kidney, and brain are similar except that there is an additional slowest-moving form of esterase in all tumor tissues. The malate dehydrogenase pattern is not altered in any of the tissues.     

Malate dehydrogenase: evidence for tetrameric structure in Mus musculus

Two electrophoretically distinct variants of supernatant nicotinamideadenine dinucleotide phosphate-dependent malate dehydrogenase exist in mice (Mus musculus). They are controlled by codominant alleles segregating at an autosomal locus. The two forms exist in a polymorphic condition in wild populations of Mus musculus and are fixed in a homozygous condition in inbred lines. These genetic electrophoretic variants are used here to study the subunit structure of this enzyme. Evidence indicating a tetrameric structure for mouse nicotinamideadenine dinucleotide phosphate-dependent malate dehydrogenase is presented. This interpretation is based on the occurrence in heterozygote tissue extracts of five electrophoretically distinct enzymes. This is the predicted phenotype for tetramers composed of two types of subunits which associate randomly in heterozygotes forming three hybrid enzymes having mobilities intermediate between the parental forms.     

乌江上游四川裂腹鱼和昆明裂腹鱼5种同工酶的比较

采用聚丙烯酰胺凝胶垂直平板电泳法(PAGE)对四川裂腹鱼和昆明裂腹鱼4种组织(肌肉、肝脏、尾鳍和性腺)的5种同工酶(LDH、MDH、ADH、EST和G-6-PDH)进行比较研究,对5种同工酶在2种鱼的组织分布、位点表达及酶谱表型作了对比分析。结果表明:LDH、MDH、ADH、EST和G6PDH 5种同工酶酶谱表型和酶带的活性在种间和种内不同组织中均表现出一定差异。同时依据其同工酶酶谱表达的复杂性和个体间多样性,探讨功能重复基因和哑基因存在的可能。     

Inhibitory action of gossypol on enzymes and growth of Trypanosoma cruzi

Gossypol, a phenolic compound isolated from the cotton plant, is a powerful inhibitor of nicotinamide adenine dinucleotide-linked enzymes (alpha-hydroxyacid dehydrogenase and malate dehydrogenase) of Trypanosoma cruzi, the parasite that causes Chagas' disease. Parasites at the epimastigote stage that were incubated for 5 minutes with 100 micromolar gossypol were completely immobilized. Concentrations of gossypol as low as 0.01 micromolar markedly reduced the growth rate of T. cruzi in culture.     

Comparative Proteomic Analysis Shows an Elevation of Mdhl Associated with Hepatotoxicity Induced by Copper Nanoparticle in Rats

Copper nanoparticle is a new material widely used in biological medicine, animal husbandry and industrial areas, but its potential toxicity to human health and environment remains unclear. In order to study the hepatotoxic mechanisms of nanoparticles copper, two-dimensional gel electrophoresis （2-DE） and matrix-assisted laser desorption/ionization time of flight mass spectrometry （MALDI/TOF MS） of proteomics technology were used to isolate and identify the differentially expressed proteins from liver, which associated with hepatotoxicity induced by copper nanoparticle in rats. In this study, we have screened 15 kinds of proteins related with hepatotoxicity, of which spot8212 was identified as Malate dehydrogenase （Mdhl）. The mRNA expression trend of Mdhl was consistent with the result of 2-DE by RT-PCR validation. Bioinformatics analysis showed that Mdhl was stable and no signal peptides, subcellular location was in endoplasmic reticulum; it contained many functional sites such as malate dehydrogenase activity signal sites 155LTRLDHNRAKSQI167; a helixes and random coils were the two main elements. Homologous analysis demonstrated high homologous of Mdhl in rats with mouse and human, and the phylogenetic tree of Mdhl was constructed. The result indicated that copper nanoparticle could regulate up the Mdhl protein expression so as to compensate the energy deficit. Energy metabolic disturbance may be a pathway for copper nanoparticle particles to exert the hepatotoxic effects in rats.     

猪囊尾蚴体内发育过程中能量代谢变化规律的研究

研究猪囊尾蚴体内发育过程中能量代谢变化规律,应用分光广度法系统地测定了体内发育过程中猪囊尾蚴磷酸烯醇式丙酮酸羧激酶(PEPCK)、丙酮酸激酶(PK)、延胡索酸还原酶(FR)、异柠檬酸脱氢酶(ICD)、苹果酸酶(ME)活性的变化及葡萄糖(GLC)含量、乳酸(LAC)含量的变化。结果表明,随虫体发育PEPCK、FR、ICD成升高趋势,PK活性和PK/PEPCK比值呈下降趋势,GLC和LAC略有升高。提示随虫体生长发育PK代谢通路减弱而PEPCK通路增强。     

Evolution of malate dehydrogenase in birds

Heart extracts from over 100 species of birds were subjected to starch-gel electrophoresis at pH 7. The "supernatant" form of malate dehydrogenase, an enzyme present in every extract, was then located on the gels by a specific staining method. The mobility of this enzyme shows very little interspecific variation. Nearly all birds tested have a supernatant malate dehydrogenase that moves as fast as the chicken enzyme. Those species with an enzyme of unusual mobility are of taxonomic interest. For example, hummingbirds and swifts, which are usually considered as two suborders of Apodiformes, are unique among the birds tested in having an enzyme that moves 63 percent as fast as the chicken enzyme. This finding appears to confirm the unity of the Apodiformes, an order whose unity has long been open to question. Similarly all families tested in the shorebird order (Charadriiformes) are unique in having an enzyme that moves 55 percent as fast as the chicken enzyme. The unity of this order was also previously open to question.     

尖孢镰刀菌异核体及其不同核型分离子的孢子萌发时期同工酶分析

在获得尖孢镰刀菌棉花萎蔫专化型异核体菌株及其3个稳定的不同核型分离子的基础上，选择孢子萌发时期的幼嫩菌丝制备粗酶提取液，采用聚丙烯酰胺凝胶电泳方法进行了7种同工酶分析。结果表明，酯酶和乳酸脱氢酶电泳图谱在4个样品中完全一致；没有致病能力的菌株在葡萄糖－6磷酸脱氢酶在苹果酸脱氢酶的表达量高于致病力强的菌株；致病力强的菌株没有乙醇脱氢酶的表达。在4个样品中都没有检测到苹果酸酶和过氧化氢酶。