Interaction of bovine immunoglobulin gamma 2 (IgG2) with staphylococcal protein A: evidence for IgG2a and IgG2b sub-subclasses in the bovine     

M J Lawman  S Joiner  D R Gauntlett  M D Boyle 《Comparative immunology, microbiology and infectious diseases》1985,8(1):1-8

The reactivity of bovine IgG with protein A is confusing with respect to which of the bovine IgG class and subclasses are reactive. We have, therefore, re-examined the interaction of bovine immunoglobulins with protein A. The results presented in this paper indicated that at pH 8.0 protein A binds only immunoglobulin of the IgG2 subclass. The bound IgG2 can be readily recovered from an immobilized protein A column at pH 5.0. Furthermore, the antigenic IgG2 eluted demonstrated two charged species which could readily be separated by ion-exchange chromatography. These results indicate that IgG2 in the bovine exists in two sub-subclasses, IgG2a and IgG2b. The two sub-subclasses of IgG2 could be rapidly isolated with a good yield in two-steps namely protein A affinity chromatography followed by ion exchange chromatography.  相似文献   

Species affinities between Cajanus cajan and some Atylosia species based on esterase isoenzymes     

T. G. Krishna  L. J. Reddy 《Euphytica》1982,31(3):709-713

Summary Esterase isozymes were studied in seed extracts of Cajanus cajan and six Atylosia species by polyacrylamide gel electrophoresis and isoelectrofocusing. The isozyme patterns were stable and accession specific. Within the accessions of the Atylosia species, A. albicans and A. scarabaeoides showed three common bands indicating that they are more closely related to each other than to the other species. Of the accessions of Atylosia only A. cajanifolia shares the esterase isozyme of C. cajan and hence seems to be the closest wild relative of C. cajan.  相似文献   

Electronegativity Scale of Elements Calculated by Density Functional Theory and Related Methods     

ZHANG Meng jun  SUN Li li  HUANG Ying  LI Zhi liang 《保鲜与加工》2002,(5):64-69

In chemistry and many related fields, electronegativity (EN) is an important fundamental concept and its scale is a useful physcochemical parameter. Here, calculations of both ionization potentials and electron affinities are extended toward 107 elements and done by density functional theory at the local density approximation(LDA) level and the LDB level, i.e., the local density approximation level with further non-local corrections for exchange and correlation included self-consistently as well as the modified Slater transition-state method. The definite-differentiation method is employed into calculations of the electronegativity scale and the related parameters of 107 elements with very good results due to the consideration of relativistic effects. The calculation presented is to examine both the LDA and LDB approximations in calculations for the ionization potential and electron affinity of the elements with an improved or modified Slater transition-state method, and relativistic effects have also been taken into account for 107 elements compared with 103, 86 or less in the previous report under a spin polarized density function theory with some approximations to the exchange-correlation function. The calculation results for the various quantities represent an obviously improvement over some previous calculations. It is shown that the results calculated by the extended technique and the improved Slater transition-state method in general agree well with experimental values presented by Pearson, and are better than the reported values in many previous literatures. The developed new electronegativity scale will widely be applicable in many fields such as molecular structural parameterization expression, chemobiological activity optimization prediction, structure-activity quantitation modeling, functional chemical adaptization designing, and so on.  相似文献   

Hybridizing <Emphasis Type="Italic">Brassica rapa</Emphasis> with wild crucifers <Emphasis Type="Italic">Diplotaxis erucoides</Emphasis> and <Emphasis Type="Italic">Brassica maurorum</Emphasis>     

Harsh Garg  Shashi Banga  Payal Bansal  Chhaya Atri  S. S. Banga 《Euphytica》2007,156(3):417-424

Two wide hybrids, Diplotaxis erucoides (2n = 14) × Brassica rapa (2n = 20) and B. maurorum (2n = 20) × B. rapa, were developed using the sequential ovary–ovule culture. Reciprocal crosses failed, possibly as a consequence of strong unilateral incompatibility. The F ₁ hybrids in each combination were completely male sterile and morphologically intermediate to the respective parents. DNA marker polymorphism and chromosome counts confirmed their hybrid nature. High frequency of bivalents in the F ₁ and the presence of trivalents/quadrivalents in the derived amphiploids suggested genomic duplications and homoeology of the parental genomes. Up to three homoeologous pairs between the D. erucoides (D^eD^e) and B. rapa (AA) genomes, and one between B. maurorum (B^mB^m) and B. rapa genomes were observed. Successful synthesis of the F ₁ hybrids and amphiploids of B. rapa with D. erucoides and B. maurorum, and allosyndetic chromosome pairing are expected to permit introgressions of desirable loci into the cultivated Brassica germplasm, especially for resistance to Alternaria brassicae and Albugo candida.  相似文献   

陆地棉与三裂棉、斯特提棉和A111种间杂种F1的形态与细胞学   总被引：2，自引：0，他引：2  

周宝良  彭跃进  沈新莲  黄骏麒  钱思颖 《作物学报》1996,22(1):84-88

本文研究了TM-1×三裂棉、江苏棉1号×斯特提棉、泗棉2号×Alll 3个种间杂种F_1的主要形态特征及花粉母细胞减数分裂中期Ⅰ的染色体行为。3个种间杂种F_1的花器官性状大多趋向于父本野生棉,如花冠颜色、花心等;营养器官大多趋向于中间型,如叶色、叶形等。杂种F_1均表现高度不育。减数分裂中期Ⅰ的染色体构型依次为:13.73Ⅰ 12.52Ⅱ 0.03Ⅲ 0.04Ⅳ,28.03Ⅰ 5.38Ⅱ 0.07Ⅲ和33.26Ⅰ 2.87Ⅱ;其染色体组亲和性指数分别为0.9715、0.4192和0.2208。这一结果表明:(1)陆地棉与三裂棉的亲缘关系较近,与斯特提棉的亲缘关系较远,与Alll的亲缘关系更远;(2)泅棉2号×Alll的F_1染色体数为2n=3x=39,其染色体数x=13与棉属相同,其次因Alll原产于澳大利亚,形态上与纳尔逊氏棉、澳洲棉比较接近,因此推测它可能属于棉属的C染色体组种。  相似文献   

Molecular characerization of the interaction between the fungal pathogen Cladosporium fulvum and tomato     

Guy Honée  Guido F. J. M. Van den Ackerveken  Henk W. J. Van den Broek  Ton J. Cozijnsen  Matthieu H. A. J. Joosten  Mirian Kooman-Gersmann  Jacques Vervoort  Ralph Vogelsang  Paul Vossen  Jos P. Wubben  Pierre J. G. M. De Wit 《Euphytica》1994,79(3):219-225

The fungus Cladosprium fulvum is a biotrophic leaf pathogen of tomato. The fungus develops in the intercellular space without forming specialized feeding structures and does not affect the leaf tissue. The outcome of the C. fulvum-tomato interaction can be described by the gene-for-gene model. Failure of infection is expressed by a hypersensitive response. Two fungal proteins, ECP1 and ECP2, have been isolated and their corresponding genes have been cloned. In a compatible interaction including many physiological races ECP1 and ECP2 are highly produced and a role in pathogenicity is suggestive. The ecp1 gene shows some homology with tumor necrosis factor receptors (TNFRs) while the ecp2 gene shows no homology with sequences known in data bases. However, disruption of one of the two genes showed no reduced pathogenicity of the fungus. Two race-specific elicitors, AVR4 and AVR9, have been isolated and their corresponding genes have been cloned. The avirulence genes Avr4 and Avr9 are only present in C. fulvum avirulent on Cf-4 and Cf-9 cultivars, respectively. The expression of these two genes is, like the expression of the ecp genes, highly induced when the fungus grows in planta. Disruption of the Avr9 gene in wild type avirulent races leads to virulence on tomato genotypes carrying the complementary resistance gene Cf-9. A single base-pair change in the avirulence gene Avr4 leads to virulence on tomato genotypes carrying the Cf-4 resistance gene. Isolation, characterization and possible function of ECP1, ECP2, AVR4, and AVR9 will be discussed.  相似文献   

南美白对虾几丁质酶的分离纯化     

马盛群 《金陵科技学院学报》2003,19(4):44-46

采用先“盐析”后“亲和吸附”的方法分离虾几丁质酶,纯化倍数为15.3倍,比活率73.3ImU·mg-1,产品得率50.6％;亲和分离胶为商品化的脱乙酰几丁质经再生后制备而成。方法简单易行适于放大生产。  相似文献   

免疫亲和层析法分离鸡补体C3d蛋白研究     

马雪云  韩建秋  高淑霞 《西北农林科技大学学报(自然科学版)》2006,34(5):55-58

利用抗鸡C3 21肽抗体制备免疫亲和层析柱,对鸡补体C3d进行了分离,并采用间接酶联免疫吸附实验(间接ELISA),对洗脱液中的C3d组分进行了检测,以SDS-PAGE电泳方法对分离到的C3d进行了检测。结果表明,利用亲和柱层析能够分离得到纯度较高的C3d蛋白,为鸡血清中C3d的提取纯化提供了较为简便的方法。  相似文献   

印度南瓜与中国南瓜有性杂交亲和性研究   总被引：11，自引：0，他引：11  

程永安  张恩慧  许忠民  王妍妮  付巧玲 《湖南农业大学学报(自然科学版)》2002,28(4):343-344

为提供用中国南瓜改良印度南瓜的理论依据，选用印度南瓜的3个栽培品种与中国南瓜的4个栽培品种进行人工杂交，观察其杂交亲和性表现。结果表明：印度南瓜P6，P7等品种与中国南瓜P2，P3，P4，P5等品种间存在杂交不亲和性，印度南瓜P1与中国南瓜P4，P5间存在杂交不亲和性，而与P2，P3间不存在杂交不亲和性。  相似文献   

野柿A砧与几个甜柿品种嫁接早期亲和力观察     

高焕章  吴楚 《湖北农学院学报》2001,21(4):316-317,346

用3个不同甜柿（Diospyros kaki)品种与野柿（Diospyros kaki var.silvestris)A砧进行嫁接亲和力对比试验。结果表明：禅寺丸麻城甜柿与野柿A砧亲和性良好，定植二年生野柿A砧后嫁接建园，接后第1年始花，第2年结果，前川次郎与野柿A砧嫁接存在明显不亲和性，少量植株嫁接当年接口呈现大、小脚现象、次年枝条生长细弱，第3年植株萎缩。  相似文献