首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Le Riche P.D. and Sewell M.M.H. 1978. Differentiation of taeniid cestodes by enzyme electrophoresis. International Journal for Parasitology8: 479–483. Interspecific differences were shown by enzyme electrophoresis in thin starch gel between Echinococcus granulosus (from horses), Taenia hydatigena, T. multiceps, T. ovis, T. pisiformis, T. saginata, T. solium and T. taeniaeformis, Differences were seen with adenylate kinase, glucose phosphate isomerase, glutamate dehydrogenase, hexokinase and malate dehydrogenase. Multiple molecular forms of glucose phosphate isomerase were clear and most species could be differentiated by this enzyme alone.No differences attributable to anthelmintic effect were seen and zymogram patterns were identical for adult and cystic forms of each species. No differences were seen between specimens collected from various geographical locations.  相似文献   

2.
A multilocus enzyme electrophoresis technique was developed to detect variation in seven enzyme loci among isolates ofPseudomonas syringae pv.phaseolicola, representing three races from different geographical locations, the causal agent of the halo blight disease of beans. Cellulose acetate gel electrophoresis of seven enzymes revealed 19 electrotypes (ET) among 21Pseudomonas syringae pv.phaseolicola isolates. One of the pathovarsyringae and one of the pathovartomato isolates were represented by two different ET. The population of Turkish isolates and three races of the pathovarphaseolicola appeared to be genetically diverse.  相似文献   

3.
4.
N P Ka?machnikov 《Biofizika》1978,23(2):247-252
A general case of the set of two differential equations, describing an open reaction v1 leads to S v reversible E P v2 leads to, has been considered. The requirements to the character of the functions v1([S]), v2([P]) and v([S], [P]) were formulated for the case of existence and absence of alternative steady states and sustained oscillations. The formulae were derived to determine the slope of the unstable portion of the quasi-steady state characteristic. The generalized model of Monod, Wyman and Changeux has been considered as an example of v([S], [P]). It has been shown that with monotonically decreasing v1 and monotonically increasing v2, the alternative steady states and oscillations are possible only in the presence of substrate inhibition or product activation. However, under the joint action of substrate inhibition and product activation, the system will exhibit bistability rather than an oscillatory behavior. In the case of an irreversible two-substrate reaction which can be described by a similar mathematical model, inhibition by the first and second substrate is equivalent to substrate inhibition and product activation.  相似文献   

5.
Abderrazak, S. B., Oury, B, Lal, A. A., Bosseno, M.-F., Force-Barge, P., Dujardin, J.-P., Fandeur, T., Molez, J.-F., Kjellberg, F., Ayala, F. J., and Tibayrenc, M. 1999. Plasmodium falciparum: Population genetic analysis by multilocus enzyme electrophoresis and other molecular markers. Experimental Parasitology 92, 232-238. The population structure of Plasmodium falciparum, the agent of malignant malaria, is uncertain. We have analyzed multilocus enzyme electrophoresis (MLEE) polymorphisms at 7-12 gene loci in each of four populations (two populations in Burkina Faso, one in Sudan, one in Congo), plus one "cosmopolitan" sample consisting of parasite cultures from 15 distant localities in four different continents. We have also performed random amplified polymorphic DNA analysis (RAPD) and restriction fragment length polymorphism (RFLP) and characterized gene varia tion at four antigen genes in the Congo population. All genetic assays show abundant genetic variability in all populations analyzed. With the isoenzyme assays, strong linkage disequilibrium is apparent in at least two local populations, the Congo population and one population from Burkina Faso, as well as in the cosmopolitan sample, and less definitely in the other Burkina Faso population. However, no linkage disequilibrium is detected in the Congo population with the molecular assays. We failed to detect any nonrandom association between the different kinds of genetic markers; that is, MLEE with RAPD or RFLP, RAPD with RFLP, and so on. Although isoenzyme data show statistical departures from panmictic expectations, these results suggest that in the areas under survey, P. falciparum populations do not undergo predominant clonal evolution and show no clear-cut subdivisions, un like Trypanosoma cruzi, Leishmania sp., and other major parasitic species. We discuss the epidemiological and taxonomical significance of these results.  相似文献   

6.
Abstract Multilocus enzyme electrophoresis (MEE) analysis and comparisons of nearly complete 16S rRNA gene sequences (1416 nucleotide positions) were used to evaluate phylogenetic relationships among Serpulina hyodysenteriae strain B78T, S. innocens strain B256T, Brachyspira aalborgi strain 513AT, and eight uncharacterised strains of swine, avian, and human intestinal spirochaetes. From MEE analysis, nine strains could be assigned to five groups containing other intestinal spirochaetes ( genetic distances between groups = 0.6–0.9). Chicken spirochaete strain C1 and B. aalborgi 513AT represented unique electrophoretic types and formed their own MEE groups. Despite MEE differences, the 11 strains had highly similar (96.3–99.9%) 16S rRNA sequences. These findings point out limitations of both MEE analysis and 16S rRNA sequence comparisons when used as solitary techniques for classifying intestinal spirochaetes related to Brachyspira/ Serpulina species.  相似文献   

7.
Electrophoretic karyotypes of yeast Saccharomyces cerevisiae integrant strains containing the pYF91 plasmid integrated into the chromosomes I, III, VI, IX, XI were studied. A possibility was demonstrated of visual identification of the chimaeric chromosomes via the molecular weight increase by 13200 bp (the plasmid size) determined by pulsed field gel electrophoresis. Several gamma-rays induced rearrangements of the yeast chimaeric chromosome I causing instability in hybrids were also studied. The deletions induced in the I chromosome were analysed and their size estimated. The technique of pulsed field gel electrophoresis is recommended for determination of insertions and deletions in the chromosomes of yeast Saccharomyces cerevisiae.  相似文献   

8.
Yeast artificial chromosome (YAC) libraries have been constructed from a variety of organisms using different approaches. This protocol outlines in detail the construction of YAC libraries with large inserts using size fractionation of partially digested DNA by pulsed-field gel electrophoresis.  相似文献   

9.
We present a top down separation platform for yeast ribosomal proteins using affinity chromatography and capillary electrophoresis which is designed to allow deposition of proteins onto a substrate. FLAG tagged ribosomes were affinity purified, and rRNA acid precipitation was performed on the ribosomes followed by capillary electrophoresis to separate the ribosomal proteins. Over 26 peaks were detected with excellent reproducibility (<0.5% RSD migration time). This is the first reported separation of eukaryotic ribosomal proteins using capillary electrophoresis. The two stages in this workflow, affinity chromatography and capillary electrophoresis, share the advantages that they are fast, flexible and have small sample requirements in comparison to more commonly used techniques. This method is a remarkably quick route from cell to separation that has the potential to be coupled to high throughput readout platforms for studies of the ribosomal proteome.  相似文献   

10.
A capillary electrophoresis-based enzyme assay for UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is described. This method, based on UV detection, provides baseline separation of one of the reaction products, enolpyruvyluridine 5'-diphospho-N-acetylglucosamine (EP-UDP-GlcNAc), from substrates phosphoenolpyruvate (PEP) and uridine 5'-diphospho-N-acetylglucosamine (UDP-GlcNAc) within 4 min. The other product, phosphate, is not detectable by UV at 200 nm. Quantitation of individual components, substrates or product, can be accomplished based on the separated peaks. This methodology was used to determine the Michaelis constant, Km, and product formation rate constant, Kcat, for MurA. Additionally, the CE method was used to evaluate the inhibition effects on MurA using one specific compound as an example. By following similar procedures, the apparent Km values in the presence of different inhibitor concentrations were determined. The inhibition constant, Ki, can be determined from these apparent Km values. In addition, this CE method can be used to study the inhibition mechanism. The principle of this approach is generally applicable to other enzyme studies.  相似文献   

11.
The electrophoretic mobilities of 12 enzymes from 19 Neisseria species (including 6 strains of N. perflava), Gemella haemolysans, Escherichia coli and Branhamella catarrhalis were characterized by polyacrylamide slab gel electrophoresis. All strains and species tested exhibited qualitatively different zymogram patterns. Species and strain relationships were quantified by pairwise comparisons of all 12 enzyme systems to obtain similarity indices; these data were subjected to numerical clustering methods to obtain groups and a phenogram. The electrophoretic classification compared favourably with those obtained by other criteria. In addition, the quantitative clustering data indicated that N. ovis and N. caviae are sufficiently different from the other Neisseria species to warrant their separation into a distinct group. These two species also lacked the characteristic NADPH-diaphorase zymogram pattern found in all the other Neisseria species. Intra-species similarity indices were generally greater than the inter-species index values. However, certain species such as N. meningitidis and N. gonorrhoeae had similarity index values in the range of inter-strain index values.  相似文献   

12.
Taxonomy of the genus Listeria by using multilocus enzyme electrophoresis   总被引:7,自引:0,他引:7  
Seventy-three strains of the seven recognized Listeria species were studied by performing a multilocus enzyme electrophoresis analysis of 18 enzyme loci. The mean number of alleles per locus was 9.5 and all of the loci were polymorphic. A total of 56 electrophoretic types were distinguished. Cluster analysis of a matrix of the genetic distances between paired electrophoretic types revealed that there were six principal clusters at the species level (genetic distances between clusters greater than 0.8). Listeria monocytogenes, Listeria innocua, Listeria welshimeri, Listeria seeligeri, and Listeria ivanovii each corresponded to one of these clusters with no overlap. Our results are in agreement with those of previous DNA hybridization experiments (Rocourt et al., Curr. Microbiol. 7:383-388, 1982). Listeria grayi and Listeria murrayi electrophoretic types formed a unique cluster, thus reinforcing the suggestion of Wilkinson and Jones (J. Gen. Microbiol. 98:399-421, 1977) that these two species should be considered two biovars of a single species.  相似文献   

13.
Summary Proteins of yeast cytoplasmic ribosomes were analyzed by two different methods of two-dimensional gel electrophoresis: run at pH 8.6 in 1-D1 and at pH 4.6 in 2-D (Method A); run at pH 5.0 in 1-D and in the presence of sodium dodecyl sulfate in 2-D (Method B). The numbers of proteins estimated were 28 (Method A) and 29 or 30 (Method B) in the 40S small subunit, and 40 (Method A) and 41 (Method B) in the 60S large subunit, respectively. Molecular weights of proteins in the small and the large subunits were found to be less than 40,000 and 60,000 respectively.  相似文献   

14.
D C Schwartz  C R Cantor 《Cell》1984,37(1):67-75
A new type of gel electrophoresis separates DNA molecules up to 2000 kb with resolutions exceeding the logarithmic molecular weight dependence of conventional electrophoresis. The technique uses 1.5% agarose, 10 to 20 micrograms of DNA per well, and low ionic strength buffers. It employs alternately pulsed, perpendicularly oriented electrical fields, at least one of which is inhomogeneous. The duration of the applied electrical pulses is varied from 1 sec to 90 sec to achieve optimal separations for DNAs with sizes from 30 to 2000 kb. This pulsed field gradient gel electrophoresis fractionates intact S. cerevisiae chromosomal DNA, producing a molecular karyotype that greatly facilitates the assignment of genes to yeast chromosomes. Each yeast chromosome consists of a single piece of DNA; the chromosome sizes are consistent with the genetic linkage map. We also describe a general method for preparing spheroplasts, and cell lysates, without significant chromosomal DNA breakage.  相似文献   

15.
A simple agarose-gel apparatus has been developed that allows the separation of DNA molecules in the size range from 50 kb to well over 750 kb, the largest size for which size standards were available. The apparatus is based on the recent discovery that large DNA molecules are readily fractionated on agarose gels if they are alternately subjected to two approximately orthogonal electric fields. The switching time, which was on the order of 20-50 sec in our experiments, can be adjusted to optimize fractionation in a given size range. The resolution of the technique is sufficient to allow the fractionation of a sample of self-ligated lambda DNA into a ladder of approximately 15 bands, spaced at 50 kb intervals. We have applied the technique to the fractionation of yeast DNA into 11 distinct bands, several of which have been shown by DNA-DNA hybridization to hybridize uniquely to different chromosome-specific hybridization probes. In this paper, we describe the design of the apparatus, the electrophoretic protocol, and the sample-handling procedures that we have employed.  相似文献   

16.
We report the study of several inhibitors on alanine aminotransferase (ALT) enzyme using sequential online capillary electrophoresis (CE) assay. Using metal ions (Na+ and Mg2+) as example inhibitors, we show that evolution of the ALT inhibition reaction can be achieved by automatically and simultaneously monitoring the substrate consumption and product formation as a function of reaction time. The inhibition mechanism and kinetic constants of ALT inhibition with succinic acid and two traditional Chinese medicines were derived from the sequential online CE assay. Our study could provide valuable information about the inhibition reactions of ALT enzyme.  相似文献   

17.
18.
Several million oligonucleotides are synthesized each year for a broad variety of molecular biology applications. Steady improvements in the synthesis chemistry efficiency and the automated DNA synthesizers have made production of oligonucleotides routine and reliable. Many applications, such as PCR and sequencing, are often successful when the primers have not been rigorously purified. To ensure an adequate level of quality and purity, rapid and convenient analytical methods are necessary for the dozens of oligonucleotides produced each day by a DNA synthesis laboratory. Traditional methods of analysis have been HPLC and polyacrylamide slab tel electrophoresis (PAGE). Gel capillary electrophoresis is a new option, combining the advantages of the HPLC and PAGE, with unprecedented resolution and speed.  相似文献   

19.
Lamotrigine, a new antiepileptic drug, is analyzed by capillary zone electrophoresis. Samples were deproteinized with acetonitrile containing an internal standard, acidified with dilute acetic acid and injected into the capillary. The drug migrated rapidly with the cationic compounds in about 3.5 min far from any interfering substances. The test was linear between 0.5–10 mg/l. The analysis time was about 5 min. The CE values correlated well with an HPLC method (r=0.97; n=35). The mean serum concentration of 121 patients on this drug was 3.7 mg/l. Incubating the serum with ß-glucuronidase for 1 h increased the peak height of lamotrigine by about 24%.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号