水稻谷蛋白是类似于豆球蛋白的蛋白质

水稻是我国的主要粮食作物,它的蛋白质含量为5—14%。在水稻种子蛋白质中,谷蛋白占80%,球蛋白占10%,醇溶蛋白占5%,清蛋白占5%。据报道,水稻种子清蛋白主要由分子量16800的亚基组成,球蛋白由10种不同分子量的亚基通过疏水交互作用相结合,谷蛋白由分子量38000、25000和16000三种亚基通过双硫键相结合:但是,Yamagata(1982)和作者(1983、1984、1986)的研究表明:水稻种子谷蛋白主要由分子量     

小麦低分子量麦谷蛋白亚基组成研究

利用改良的两步一向SDS—PAGE(two—step one—dimensional SDS—PAGE)分析了几种小麦低分子量麦谷蛋白亚基(LMW-GS)组成。70％热乙醇提取总谷蛋白,11％分离胶进行第一步SDS—PAGE分离．电泳1h后切取顶端1cm胶条并置于巯基乙醇溶液进行还原,还原后的胶条于11%～16．5％的梯度胶进行第二步SDS—PAGE分离。结果显示。两步一向SDS—PAGE可以彻底除去清蛋白、球蛋白和醇溶蛋白对LMW—GS分离的背景干扰。提高LMW—GS的分辨率。对几种小麦低分子量麦谷蛋白亚基分析表明：LMW-GS组合比HMW—GS更为丰富,每种小麦含有2～5种B亚基,2～4种C亚基．B、C亚基的总数量为4～8种。     

甜荞不同品种不同海拔地区种子蛋白组分含量研究

该研究通过分析甜荞10个品种在4个不同海拔栽培的种子蛋白质组分(清蛋白、球蛋白、醇溶蛋白和谷蛋白)的含量变异,以揭示不同荞麦品种之间以及不同栽培地点甜荞种子蛋白组分的变异规律。结果表明:在所有甜荞品种种子蛋白组分含量中清蛋白谷蛋白球蛋白醇溶蛋白。其中,种植于海拔最低的内蒙古通辽的甜荞种子平均球蛋白含量最高(1.081%),而种植于海拔1 450 m的河北甜荞谷蛋白平均含量最高(2.805%);海拔2 620 m的青海甜荞清蛋白平均含量为4.750%,而在海拔最高的西藏日喀则收获的甜荞种子的醇溶蛋白最高(平均为0.393%)。另外,蒙0530在4个地区的平均种子清蛋白和谷蛋白含量都最高,而球蛋白含量最高的品种是赤甜荞1号,定甜荞2号的种子醇溶蛋白含量最高。双因素方差分析表明,种子清蛋白含量品种间变异达极显著水平,不同地点间的种子醇溶蛋白含量达极显著水平,而地点和品种两个因素对种子球蛋白含量和谷蛋白含量的变异都有极显著影响。相关性分析表明,赤甜荞1号的醇溶蛋白含量与海拔呈显著正相关,蒙0530的球蛋白含量与海拔呈显著负相关,其他品种蛋白组分与海拔的相关性不显著。该研究结果对于甜荞优质品种培育和栽培以及推广都有一定的指导意义。     

植物种子贮藏蛋白质及其细胞内转运与加工

高等植物种子成熟过程中贮存大量的贮藏蛋白质作为种子发芽和初期生长的重要营养来源。根据溶解性不同,种子贮藏蛋白质可分为白蛋白、球蛋白、醇溶蛋白和谷蛋白4类。在种子胚发育过程中,醇溶蛋白在粗面内质网合成后形成蛋白质聚集体,直接出芽形成蛋白体并贮存其中。白蛋白、球蛋白和谷蛋白在粗面内质网以分子量较大的前体形式合成后,根据各自的分选信号进入特定的运输囊泡,经由受体依赖型运输/聚集体形式运输转运至蛋白质贮藏型液泡中,然后经过液泡加工酶等的剪切转换为成熟型贮藏蛋白质并贮存其中。蛋白质的合成、分选、转运和加工等过程影响种子蛋白质的品质及含量。该文对种子贮藏蛋白质的分类和运输、加工以及这些过程对种子蛋白质品质和含量的影响进行了概述。     

植物种子贮藏蛋白质及其细胞内转运与加工

高等植物种子成熟过程中贮存大量的贮藏蛋白质作为种子发芽和初期生长的重要营养来源。根据溶解性不同, 种子贮藏蛋白质可分为白蛋白、球蛋白、醇溶蛋白和谷蛋白4类。在种子胚发育过程中, 醇溶蛋白在粗面内质网合成后形成蛋白质聚集体, 直接出芽形成蛋白体并贮存其中。白蛋白、球蛋白和谷蛋白在粗面内质网以分子量较大的前体形式合成后, 根据各自的分选信号进入特定的运输囊泡, 经由受体依赖型运输/聚集体形式运输转运至蛋白质贮藏型液泡中, 然后经过液泡加工酶等的剪切转换为成熟型贮藏蛋白质并贮存其中。蛋白质的合成、分选、转运和加工等过程影响种子蛋白质的品质及含量。该文对种子贮藏蛋白质的分类和运输、加工以及这些过程对种子蛋白质品质和含量的影响进行了概述。     

不同品种水稻种子贮藏蛋白质组分的差异

水稻是我国的主要粮食作物,它的蛋白质含量为6—14%。在水稻种子蛋白质中,谷蛋白占80%,球蛋白占10%,醇溶蛋白占5%,清蛋白占5%。据研究,水稻种子清蛋自主要由分子量16800的亚基组成,球蛋白由10种不同分子量的亚基通过疏水交互作用相结合,谷蛋白由分子量38000、25000和16000三种亚基通过双硫键相结合。但是,不同品种水稻种子贮藏蛋白质组分有何差异?研究报道的很少。本文简要报道不同品种水稻种子(籼稻和粳稻)贮藏蛋白质组分的差异,为     

3种生态型翅果油树种子贮藏蛋白分析

采用考马斯亮蓝G-250染色法和SDS-PAGE电泳技术对翅果油树3种生态类型种子贮藏蛋白含量进行测定和图谱分析.结果显示:大宫灯、长果型、小宫灯3种生态类型种子中总贮藏蛋白含量分别为33.753%、32.075%和26.633%;3种生态类型种子贮藏蛋白均以谷蛋白含量最高(65.971%～68.267%),其次为球蛋白和清蛋白,醇溶蛋白的含量最低;电泳图谱显示,3种生态类型之间清蛋白、球蛋白、醇溶蛋白和谷蛋白的蛋白质条带信息均存在差异.研究表明,翅果油树3种生态类型间种子贮藏蛋白具有多态性.     

水稻谷蛋白突变体的筛选及遗传分析

通过对国内外水稻品种种子的全蛋白分析,筛选到3个谷蛋白突变材料。其中编号W3660种子中37～39kDa与22～23kDa谷蛋白亚基的含量较普通水稻明显降低,而13kDa醇溶蛋白多肽含量则大幅升高;W204和W379种子中37～39kDa与22～23kDa谷蛋白亚基的含量介于普通品种与W3660之间,W379还具超大含量的57kDa多肽,实验证明此多肽属谷蛋白成分。用W3660和普通水稻栽培品种惊人糯(Otorokimochi)构建了杂交群体。后代种子总蛋白SDS-PAGE分析显示,低谷蛋白和高醇溶蛋白性状总是相伴出现;F1种子全部呈现低谷蛋白含量和高醇溶蛋白含量特性;F2种子中呈现低谷蛋白和正常蛋白性状的比例约为3：1;从F3种子分析推断出的F2植株基因型,其低谷蛋白纯合型,杂合型和正常型的分离比例符合1：2：1。表明,W3660的低谷蛋白和高醇溶蛋白性状是由单显性基因控制,而且能稳定地遗传给后代。     

薏苡仁蛋白质组分研究

目的：对药食两用功能的薏苡仁蛋白质四类组分和氨基酸含量进行分析。方法：采用旋光法、索氏提取法、烘干法、马弗炉法分别进行淀粉、粗脂肪、水分和灰分的测定;采用顺序抽提法依次进行清蛋白、球蛋白、醇溶蛋白和谷蛋白的提取,用Brandford和凯式定氮法进行蛋白质含量分析;采用氨基酸分析仪进行氨基酸含量测定。结果：薏苡仁总蛋白含量为14．17％,其中清蛋白、球蛋白、醇溶蛋白和谷蛋白含量分别为0．20、0．88、6．34和5．30mg／100mg鲜重,分别占总蛋白质含量的1．43％、6．20％、44．74％和37．38％;薏苡仁粉经酸水解后共检测到15种氨基酸,除Trp外,人体必需氨基酸和半必需氨基酸均有检测到;各氨基酸含量也存在着差异,含量最高的为Glu（3．59mg／100mg）,含量最低的为Met（0．17mg／100mg）。结论：薏苡仁蛋白中醇溶蛋白和谷蛋白含量较丰富,为今后进一步开发薏苡仁功能食品提供了理论数据。     

溶脲脲原体12个血清型标准株与6个地方分离株主要蛋白组份的分析

经SDS—PAGE和薄层扫描分析,18株溶脲脲原体有从分子量19—175KD 20多条蛋白区带。主要蛋白组份分布在32—140KD范围之间。其中32、52和94KD蛋白组份各株间差别较大,而其余主要蛋白组份各株间较类似。按蛋白组份的不同可将溶脲脲原体分为A、B两群。^群包括2、5、7、9、10、11、12血清型标准株和U_C、U_D、U_E、U_F地方分离株。B群包括1、3、6、13、14和U_A、U_B株。仅用SDS—PAGE方法分析溶脲脲原体蛋白组份不能区别菌株间的血清型。     

蛋白酶抑制剂对含水生菜种子耐冻性的影响

选取生菜(Lactuca sativa)种子作为试材,外源添加蛋白酶抑制剂2-硝基苯甲酸[5,5'-Dithiobis-(2-nitrobenzoic acid),DTNB]对种子吸胀处理,通过程序降温,分析2-硝基苯甲酸对低温下种子发芽率及生理活性的影响。结果表明,低温下含水生菜种子的致死温度为–20 ℃;外源添加2-硝基苯甲酸2 mmol·L–1时种子发芽率最高,即对种子活性的保护效果显著;在此浓度下种子内SOD活性比对照提高1.38倍,羟基自由基清除能力提高1.17倍;与对照组相比产生两种新的蛋白11 S种子贮藏球蛋白Jug r4和11 S种子贮藏球蛋白2,均属于球蛋白家族,可提高含水种子的耐冻性;低温下种子内积累更小分子量的球蛋白多肽,对种子具有低温保护效果。综上,低温条件下生菜种子产生一定的抗冷反应,外源添加2 mmol·L–1 2-硝基苯甲酸可提高含水种子发芽率及生理活性,产生抗冻蛋白,积累更小分子量的球蛋白多肽进而提高种子抗冻性。     

坛紫菜（Porphyra Haitanensis）中抑菌活性肽的制备与初步纯化

目的:提取坛紫菜中水溶性蛋白,并对其进行初步纯化和抑菌活性影响因素研究。方法:坛紫菜水溶性蛋白胃蛋白酶在37℃、pH1.8条件下酶解3h,再经超滤、Bio-Gel P-10和DEAE Sephadex A-50层析纯化步骤得到一定分子量范围的多肽混合物。采用平板打孔法和对金黄色葡萄球菌的抑制作用,跟踪测定活性多肽纯化过程及其活性影响因素。结果:SDS-PAGE测定结果表明该抗菌多肽分子量介于43.0KD~66.2KD之间。它对金黄色葡萄球菌生长的抑制作用随着温度的升高逐渐减弱,5%EDTA、5%柠檬酸、5%维生素C及25%二甲基亚砜对它的抑菌活性有协同作用,而5%维生素E则对它的抑菌活性有拮抗作用。结论:从坛子菜水溶性蛋白中初步纯化得到的分子量介于43.0KD~66.2KD的多肽,对金黄色葡萄球菌的生长有明显地抑制作用,并且它的抑菌活性受到温度,部分有机酸和维生素的影响。     

Etude de la globuline des graines de Tournesol (Helianthus annuus L.) accumulation au cours de la maturation et localisation intracellulaire

Protein synthesis and accumulation in growing sunflower (Helianthus annuus L.cv.Airelle) seeds are studied. The salt soluble fraction, globulin, is the main soluble protein component. The earlier stages of seed development (10 days after flowering) are characterized by high M_r polypeptides (74, 58 and 44 kDa). Later stages mainly show nature globulin polypeptides. Thus, protein synthesis in seed occurs at a specific period of seed development which follows a period of fast cell divisions (0–14 days after flowering). Protein bodies are isolated and their protein composition analyzed. Globulin subunits are the main polypeptides of protein bodies soluble fraction. Mature globulin is only stored in protein bodies.      

坛紫菜（Porphyra Haitanensis）中抑菌活性肽的制备与初步纯化

目的：提取坛紫菜中水溶性蛋白,并对其进行初步纯化和抑菌活性影响因素研究。方法：坛紫菜水溶性蛋白胃蛋白酶在37℃、pH1.8条件下酶解3h,再经超滤、Bio-Gel P-10和DEAE Sephadex A-50层析纯化步骤得到一定分子量范围的多肽混合物。采用平板打孔法和对金黄色葡萄球菌的抑制作用,跟踪测定活性多肽纯化过程及其活性影响因素。结果：SDS-PAGE测定结果表明该抗菌多肽分子量介于43.0KD~66.2KD之间。它对金黄色葡萄球菌生长的抑制作用随着温度的升高逐渐减弱,5%EDTA、5%柠檬酸、5%维生素C及25%二甲基亚砜对它的抑菌活性有协同作用,而5%维生素E则对它的抑菌活性有拮抗作用。结论：从坛子菜水溶性蛋白中初步纯化得到的分子量介于43.0KD~66.2KD的多肽,对金黄色葡萄球菌的生长有明显地抑制作用,并且它的抑菌活性受到温度,部分有机酸和维生素的影响。     

Biochemistry of Fern Spore Germination: Globulin Storage Proteins in Matteuccia struthiopteris L

Two globulin storage proteins have been identified in spores of the ostrich fern, Matteuccia struthiopteris (L.) Todaro. The two proteins comprise a significant amount of the total spore protein, are predominantly salt-soluble, and can be extracted by other solvents to a limited extent. The large 11.3 Svedberg unit (S) globulin is composed of five polypeptides with molecular weights of 21,000, 22,000, 24,000, 28,000 and 30,000. Each polypeptide has several isoelectric point (pI) variants between pH 5 and 7. The small 2.2S storage protein has a pI > 10.5 and is composed of at least two major polypeptides of 6,000 and 14,000 M_r. The amino acid composition of both storage proteins reveals that the 11.3S protein is particularly rich in aspartic and glutamic acid, while the 2.2S protein has few acidic amino acids. During imbibition and germination the globulin fraction declines rapidly, with a corresponding degradation of individual polypeptides of each protein. Polyclonal antibodies against each of the two proteins were produced and used for immunolocalization to determine the site of storage protein deposition within the quiescent spore. The proteins were sequestered in protein bodies of 2 to 10 micrometers, that are morphologically similar to those found in the seeds of flowering plants. The results suggest that spore globulins are biochemically similar to seed globulins, especially those found in some cruciferous seeds.     

Antigenic analysis of purified surface antigens of filarial nematode Setaria digitata.

The surface antigens of S. digitata were isolated by treatment with Triton X-100. In non SDS-PAGE the surface antigen preparation resolved into more than 6 protein bands. Electroelution of gel slices corresponding to the protein bands with relative mobilities 0.09, 0.32, 0.41, 0.53, 0.61 and 0.76 gave 6 purified surface antigen fractions (SAF). Analysis of SAFs by SDS-PAGE showed that the proteins with molecular weights 17, 29 and 36 KD were the three major polypeptides and different combination of these gave rise to the 6 native surface proteins. The 29 KD protein existed as a monomer and as cross-linked with the 17 and 36 KD proteins. All surface antigen fractions showed antigenicity, where as 29 KD protein remained as a high avidity surface antigen.     

Combined 2D electrophoretic approaches for the study of white lupin mature seed storage proteome

Seed proteome analysis by 2D IEF/SDS-PAGE techniques is challenging for the intrinsic difficulties related to quantitative disparity of the seed proteins, i.e. storage and non-storage proteins, their polymorphic nature, the extensive post-translational modifications and the paucity of deposited primary structures available. Conversely, 2D maps of seed proteomes can be extremely useful for a number of fundamental and applied investigations. In this work, we have used a combination of two experimental approaches to identify the main protein components of an emerging protein-rich legume seed, that is white lupin seed (Lupinus albus, L.). One is the canonical proteomic approach including 2D electrophoretic separation and mass spectrometry of selected trypsin-digested polypeptides; the other approach is a group comparative 2D electrophoretic analysis of cotyledonary protein families. To this second purpose, the three main families of lupin seed proteins, namely alpha-conglutins, the 11S globulin fraction, beta-conglutins, the 7S globulin fraction, and gamma-conglutin, a basic 7S protein, were isolated by conventional biochemical techniques and their 2D reference maps were compared with the total protein map. With the first approach 37 out of 40 spots, making up about 35% of total spot volumes in the 2D map, were found to belong to the main seed protein families. Thanks to cDNA-deduced lupin storage protein sequences, determined on purpose and deposited, most of the identification statistical parameters were very good. Moreover, it was possible to identify several endogenously proteolysed subunits in the map. The second comparative approach, beside confirming these attributions, allowed to allocate 124 polypeptides within the three main lupin protein families. These two approaches proved to be mutually validating and their combined use was effective for the establishment of a seed proteome map even in the case of sequence and protein post-translational processing lack of information. The results obtained also extend our knowledge of the seed storage protein polymorphism of white lupin.     

花生种子老化相关蛋白质的初步研究

本文以粤油 116花生(Arachis hypogaea L.)为材料,对不同处理种子的除子叶“种胚”(以下简称“种胚”)的蛋白质进行了研究.实验结果表明,当花生种子活力下降到一定程度时,其“种胚”内出现一种新蛋白质( pI6.2、MW 10 KD),随种子老化程度加深,含量逐渐增多.我们认为该蛋白质与花生种子老化存在着一定的相关关系,可作为该种子老化的标志.     

A protein factor from Bufo marinus erythrocytes cross-bridges microtubules in vitro

A microtubule cross-bridging factor was isolated from erythrocytes of the toad, Bufo marinus. Erythrocytes were lysed and their cytoskeletons disassembled by sonication and high salt extraction. The solubilized proteins were recovered and fractionated using Sephadex G-200 column chromatography. The protein fractions from the column were analysed by SDS-PAGE and pooled into three groups: high molecular weight (HMW) proteins that eluted from the column in the void volume and had a protein composition that included HMW polypeptides; intermediate MW proteins that were shown by SDS-PAGE to contain polypeptides smaller than 120,000 D; and low MW (LMW) proteins that contained polypeptides smaller than 70,000 D. Each group was further fractionated by phosphocellulose (PC) chromatography. The flow-through was recovered, and bound proteins were then eluted by a step gradient of salt (0.2, 0.4, 0.6 and 0.8 M KCl). To assay for microtubule cross-bridging activity, column fractions were incubated with taxol-stabilized microtubules, formed from PC-purified brain tubulin (PC microtubules). Negatively stained samples were examined in the electron microscope for the reconstitution of microtubule bundles with interconnecting cross-bridges. The HMW protein fraction from the G-200 column contained the cross-bridging factor. When these proteins were further fractionated by PC chromatography only the fraction eluted by 0.2 M KCl induced the formation of microtubule bundles with cross-bridges. No other protein fraction isolated by the described method revealed cross-bridges between microtubules in vitro.     

花生种子老化相关蛋白质的初步研究

本文以粤油 116花生(Arachis hypogaea L.)为材料,对不同处理种子的除子叶“种胚”(以下简称“种胚”)的蛋白质进行了研究.实验结果表明,当花生种子活力下降到一定程度时,其“种胚”内出现一种新蛋白质( pI6.2、MW 10 KD),随种子老化程度加深,含量逐渐增多.我们认为该蛋白质与花生种子老化存在着一定的相关关系,可作为该种子老化的标志.