玉米酯酶同工酶和过氧化物酶同工酶的分子量研究

本试验利用聚丙烯酰胺凝胶梯度电泳分步染色法直接对玉米苗期酯酶同工酶和过氧化物酶同工酶各酶带的分子量进行了比较测定。酯酶同工酶 E_1、E_2、E_3~F、E_3~S、a、b、c 各酶带的分子量分别为<20000,35200、33000、38500、29900、28500、34000道尔顿过氧化物酶同工酶 PX_4~F和 PX_4~S酶带的分子量分别为131000和149000道尔顿。根据酶带在均匀胶和梯度胶中的位置变化对各酶带的生化性质作了初步分析,发现 E_3~F和 E_3~S、PX_4~F 和 PX_4~S 在迁移率上的差异主要是分子量的差异。本文为同工酶的分子量测定提供了一个简便的方法。     

同工酶技术及其优化

同工酶电泳法是一种常用的遗传多样性分析方法,具有成本低、耗时少和操作简单等优点。主要介绍了同工酶电泳法,过氧化物酶、酯酶和超氧化物歧化酶的染色技术,以及同工酶电泳的优化方法,以促进同工酶电泳分析技术在生物学、食品和制药等各领域的应用。     

血清胆碱酯酶与血脂的关系

通过对749例40～60岁工人SChE和血脂水平的分析,结果显示SChE与TC、TG、LDL-C和VLDL-C呈正相关,与HDL-C呈负相关,相关系数分别为0.21,0.23,0.12,0.11和-0.08。高脂血症患者的SChE活性(2271.8±650.7u/L)高于血脂正常者(1968.6±607.0u/L),但冠心病患者的SChE活性(2242.8±499.4u/L)与高脂血症组无差异。在各型高脂血症中,只有高甘油三酯血症(2241.5±623.9u/L)和混合性高脂血症患者(2561.5±704.8u/L)的SChE活性增高,而高胆固醇血症患者的SChE活性(2034.8±640.0u/L)与血脂正常者无差异(p>0.1)。提示SChE与血脂之间存在一定的联系,本文对此关系进行了讨论。     

人血红素加氧酶同工酶的分离纯化初报

首次报道了人肝脏血红素加氧酶的同工酶的分离纯化,并初步探讨了它们的性质,采用ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－２５和羟基磷灰石柱层析法从人肝脏分离纯化ＨＯ的同工酶,酶活性检测、ＳＤＳ－ＰＡＧＥ分析结果显示,人肝脏微粒体含量ＨＯ的同工酶,按洗脱先后顺序分别得到分子量为３００００和３６０００的ＨＯ－１和ＨＯ－２．酶促反应中需相同辅酶参与,其中酶活性ＨＯ－１明显高于ＨＯ－２,两之比为２．４：１,从分子量和     

鹿科动物血清LDH同工酶的比较分析

鹿科动物血清ＬＤＨ同工酶的比较分析ＡＣＯＭＰＡＲＡＴＩＶＥＡＮＡＬＹＳＩＳＯＮＴＨＥＳＥＲＵＭＬＤＨＩＳＯＺＹＭＥＳＩＮＤＥＥＲＳ￥ＷＡＮＧＹｕｎｌｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｌｏｇｙ,ＴｉａｎｊｉｎＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ）ＬＵＢ...     

草鱼同工酶发育遗传学研究——Ⅰ.不同组织器官的同工酶分析

采用垂直淀粉凝胶电泳及特异性组织化学染色技术,研究了草鱼成体脑、眼、心、肾、肌、肝等6种组织中的6种同工酶系统(LDH、MDH、GDH、ADH、LDH、EST)的分化表达谱式。结果表明,草鱼的同工酶系统具有明显的组织特异性。与绝大多数硬骨鱼类相比,草鱼的LDH、m-MDH和ADH同工酶具有特殊的表达谱式:m-MDH和ADH均由两个基因座位编码;肾脏在LDH-A_3B与LDH-A_2B_3之间多出1条LDH酶带(LDH-X)。本文还讨论了草鱼同工酶的遗传基础和亚基组成,以及本实验的某些结果与其他作者的结果不相符的原因。     

冬瓜杂种一代及其亲本的同工酶比较研究

对冬瓜芽期子叶的酶提取液进行聚丙烯酰胺凝胶电泳,分析了过氧化物酶（ＰＥＲ）、酯酶（ＥＳＴ）、苹果酸脱氢酶（ＭＤＨ）同工酶以及蛋白质电泳结果．通过电泳结合光密度扫描研究,发现冬瓜杂种一代“粉杂”与其双亲的过氧化物酶同工酶差异显著．过氧化物酶同工酶可以作为鉴别冬瓜假杂种的生化指标．     

鸭血清胆碱酯酶的纯化及性质研究

首次采用新技术双水相萃取方法作为鸭血清胆碱酯酶(EC.3.1.1.8 CHE) 纯化的第一步,后经 DEAE-Sephadex A50,sephadex G200 柱层析,获得电泳纯鸭血清胆碱酯酶,提纯倍数1018倍,酶活力回收43.4%,比活274.9U/mg。鸭血清胆碱酯酶性质研究表明:此酶是糖蛋白和酸性蛋白水解酶,等电点 4.2 左右,最适 pH7.5 左右;对底物碘化硫代丁酰胆碱的 K_m=9.8×10^-5mol/L;SDS-PAGE 电泳和聚丙烯酰胺梯度电泳表明,鸭血清胆碱酯酶以相同亚基组成的不同聚合体形式存在,亚基分子量 78000,具有完整的酶活性.不同聚合体带电状态相同.     

几种芦荟SOD同工酶谱、酶活性比较

通过聚丙烯酰胺凝胶电泳法和NBT光化还原法,测定分析了9种芦荟的SOD同工酶酶谱和酶活性,结果表明,翠叶芦荟含6种SOD同工酶,蕃拉芦荟和中华芦荟均含有4种SOD同工酶,其余6种芦荟均含有3种SOD同工酶,SOD酶活性由强至弱依次为翠叶芦荟,蕃拉芦荟,中华芦荟,开普芦荟,日本芦荟,皂质芦荟,上农大叶芦荟,多肉芦荟,斑叶芦荟,供试的9种芦荟中,经济价值最高的是翠叶芦荟,其次是蕃拉芦荟,中华芦荟和开普芦荟。     

大熊猫乳酸脱氢酶同工酶H_4的分离纯化和某些性质的研究

采用８－（６－氨己基）－氨基－５＇－ＡＭＰＳｅｐｈａｒｏｓｅ亲和层析法和ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ离子交换层析法从大熊猫心肌中分离纯化出了乳酸脱氢酶同工酶Ｈ４．纯化的大熊猫ＬＤＨ－Ｈ４,比活为４４５Ｕ／ｍｇ蛋白,经ＳＤＳ－ＰＡＧＥ,ＰＡＧＥ,等电聚焦电泳鉴定均为一条带,其亚基分子量为３６０００,等电点为５．４５．经测定大熊猫ＬＤＨ－Ｈ亚基Ｎ端被封闭,Ｃ端氨基酸残基经测定为Ｌｅｕ．氨基酸组成分析表明每个亚基含有５个Ｃｙｓ,９个Ｍｅｔ．     

Carbonic Anhydrase Inhibitors. Inhibition of Cytosolic Isozymes I and II and Transmembrane,Cancer-associated Isozyme IX with Anions

Except for sulfonamides, metal complexing anions represent the second class of inhibitors of the zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1). The first inhibition study of the transmembrane, tumor-associated isozyme CA IX with anions is reported here. Inhibition data of the cytosolic isozymes CA I and CA II with a large number of anionic species such as halides, pseudohalides, bicarbonate, nitrate, hydrosulfide, arsenate, etc., are also provided for comparison. Isozyme IX has an inhibition profile by anions different in some aspects from those of CA I and CA II, that may have interesting physiological consequences.     

Changes of Activity and Isozyme Pattern of Phosphofructokinase in the Brains of Patients with Alzheimer's Disease

Abstract: A severe reduction of the in vivo cerebral glucose consumption rate is generally found in patients with Alzheimer's disease. In postmortem studies changes in the activities of key regulatory glycolytic enzymes, including 6-phosphofructokinase (PFK), have been reported in Alzheimer's disease brains, but the results obtained so far are inconsistent and controversial. We reevaluated the activity of PFK in brain tissue from clinically and neuropathologically confirmed cases of Alzheimer's disease using optimized tissue disintegration and assay methods and determined the PFK isozyme pattern. PFK activity in brains from patients with Alzheimer's disease was significantly increased in frontal and temporal cortex and unchanged in the other brain areas studied when compared with control brains. All three PFK isozymes were detected in each of the brain areas studied. In brains of Alzheimer's disease patients the level of the C-type PFK was slightly reduced at the expense of the M- and L-type subunits. The data presented do not support the results of other groups, which reported up to a 90% reduction of PFK activity in Alzheimer's disease. In contrast, the data presented clearly rule out the suggestion that changes of PFK activity might be one of the causes for the reduced glucose consumption in Alzheimer's disease brains.     

Carbonic Anhydrase Inhibitors. Inhibition of Cytosolic Isozymes I and II and Transmembrane,Cancer-associated Isozyme IX with Lipophilic Sulfonamides

A series of new compounds was obtained by reaction of aromatic/heterocyclic sulfonamides incorporating amino groups with N,N-diphenylcarbamoyl chloride and diphenylacetyl chloride. These sulfonamides were assayed for the inhibition of three carbonic anhydrase (CA, EC 4.2.1.1) isozymes: the cytosolic CA I and CA II, and the transmembrane, cancer-associated isozyme CA IX. Good inhibitors against all these isoforms were detected, and the inhibition profile of the newly investigated isozyme IX was observed to be different from that of the cytosolic isozymes, I and II. This may lead to the development of novel anticancer therapies based on the selective inhibition of CA IX.     

同工酶在半翅目昆虫中的应用及展望

本文就近二十几年来同工酶在半翅目昆虫中的研究进展进行了归纳 ,认为同工酶在半翅目昆虫的分类研究、进化研究以及捕食者—猎物关系的研究中有着十分广泛的应用前景。     

不同类型杂交水稻组合及其亲本苗期同工酶位点分析

对6个杂交水稻组合及其亲本苗期14种酶的同工酶进行检测,并对其中较为清晰稳定的酶带进行了位点分析,以探讨杂种优势遗传基础。共获得了28个位点的相关资料,包括每个位点的性质、表型多态性和每个位点所编码的酶活性及酶带平均迁移率。所有供试材料在其中25个位点上均未表现出多态性,只有部分组合与其亲本在Est-4、Amy-1、Aat-2等3个位点上存在多态性,其中有81．8％的差异组合其酶带表现出共显性特征。对共显性与杂种优势的关系进行了探讨。     

Synthesis of S-adenosylmethionine synthetase isozymes from rat and mouse livers: Immunochemical studies

The α- and β-forms of S-adenosylmethionine synthetase in rat liver were completely fractionated by chromatography on a hydrophobic resin, phenyl-Sepharose. The α-form was eluted in low-ionic strength buffer, and the β-form was eluted with 50% dimethylsulfoxide. The α-form is less sensitive to dimethylsulfoxide, whereas the β-form is strikingly stimulated by dimethylsulfoxide, after removal of the dimethylsulfoxide. The levels of the α-form activity in rat liver after treatment with ethionine and adenine for 2 consecutive days, and those of the β-form activity in mouse liver on the 12th day after transplantation of Ehrlich ascites tumor cells, were increased several fold compared to normal liver. Immunochemical titrations with specific antibody against the β-form as well as kinetic studies indicated that the observed increase in the levels of each activity from the S-adenosylmethionine synthetase isozymes is due to an increase in the cellular content of the enzyme.     

Studies on the Molecular Weights of Esterase and Peroxidase Isozymes of Maize

The molecular weights of esterase and peroxidase isozymes of maize seedlings were directly determined by improved polyacrylamide gradient gel electrophoresis. The different isozyme bands developed in polyacrylamide slab gel electrophoresis (uniform gel) were identified in polyacrylamide gradient gel electrophoresis by means of isozyme variants. The molecular weights of esterase isozymes E1, E2, E3F, E3S, a, b, c, named according to isozyme patterns in uniform gel, are <20000, 35200, 33000, 38500, 29900, 28500, 34000 doltons respectively. The molecular weights of peroxidase isozymes PX4F and PX4S are 131000 and 149000 doltons respectively. According to the band location in uniform gel and in gradient gel, some biochemical properties of the isozyme bands and relationships between the isozyme bands were analyzed. The possible errors in the determination of smaller molecular weight isozymes are discussed.     

不同品种南瓜POD及PPO同工酶的比较研究

采用垂直平板聚丙烯酰胺凝胶电泳技术,对美洲南瓜（Cucurbita pepo L.）和中国南瓜（C.moschata Duch.）共10个不同栽培品种的过氧化物酶（POD）及多酚氧化酶（PPO）同工酶进行了分析研究,并采用聚类分析法对其亲缘关系进行了比较和分类。结果表明,10个不同品种的南瓜根POD共分离出10条酶带,其中el、e4、e5、e6和e9为2个栽培种所共有;e4、e5、e6分离清晰,可作为2个栽培种的特征酶带;PPO同工酶分离出6条酶带,其中e′1和e′4分离清晰,为2个栽培种所共有。