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1.
Four arginine ester hydrolases, ME-1, 2, 3 and 4 from the venom of Trimeresurus mucrosquamatus had been isolated and characterized by Sugihara et al. (1980, 1981, 1982, 1983). Immunologically, ME-1, 2, 3 and 4 are identical. The four enzymes hydrolyzed Pro-Phe-Arg-MCA and z-Phe-Arg-MCA. Furthermore, ME-2 slightly hydrolyzed Boc-Val-Pro-Arg-MCA, Boc-Phe-Ser-Arg-MCA and Boc-Ile-Glu-Gly-Arg-MCA. ME-1 cleaved almost simultaneously the Arg(22)-Gly(23) and Phe(25)-Tyr(26) bond of oxidized insulin B chain. ME-2 and 3 also hydrolyzed the same bond of insulin B chain, but the activity was not as potent as ME-1. ME-4 did not cleave the substrate. The four enzymes hydrolyzed C-terminal of arginine in the biologically active peptides. Four arginine ester hydrolases showed fibrinogenolytic activity. ME-1 and 2 first cleaved B beta-chain and then A alpha-chain. On the contrary, ME-3 and 4 cleaved A alpha- and B beta-chain simultaneously. The four enzymes also hydrolyzed fibrinogen in plasma cleaving B beta- and gamma-chain and slightly digesting A alpha-chain. The various inhibitors affected TAME (tosyl-arginine-methylester) and the fibrinogen hydrolytic activity of the four enzymes. All four enzymes had fibrinolytic activity.  相似文献   

2.
The helminth community of the wood mouse, Apodemus sylvaticus, in the Sierra Espuna was characterized after a complete analysis of its helminth community component and infracommunity structure relative to host age, sex and year of capture. The helminth community comprised 13 species: one trematode, four cestodes and eight nematodes. The cestode Pseudocatenotaenia matovi and the nematode Syphacia frederici were the most prevalent and abundant helminth species, respectively. Sixty four percent of mice analysed presented helminths with a direct cycle and 42% presented helminths with an indirect cycle. The helminth community presents a low diversity with infracommunities usually made up of only one or two helminth species. Host age and year of capture seem to play a major role in determining species richness and helminth diversity, but not in determining the abundance of helminths. Host sex does not seem to affect the infection rate nor the diversity. Further studies on more samples of wood mice and other small mammal species in this regional park are needed to explore any possible interactions between helminth communities in the host populations.  相似文献   

3.
A diastereomeric mixture and the four stereoisomers of 2,6-dimethyloctane-1,8-dioic acid (2), a copulation release pheromone of the cowpea weevil, Callosobruchus maculatus, were synthesized. The stereoisomeric purities of the four synthetic isomers of 2 were determined by the HPLC analyses of their bis-2-(2,3-anthracenedicarboximide)-1-cyclohexyl esters.  相似文献   

4.
The projections of four anatomically distinct groups of putative neurosecretory cells found within the supra-oesophageal ganglion of the leech Macrobdella decora were studied by intracellular injection of horseradish peroxidase. All four groups have their own characteristic branching pattern while sharing the common feature of possessing primary branches that project into the dorsal commissure. Numerous secondary processes extend from these primary branches to terminate within the neural lamella, as well as within the neuropile. Electron microscopy of the regions into which these secondary processes project reveals numerous neurosecretory terminals. The data suggests that the midregion of the dorsal commissure constitues a neurohemal complex. These observations strengthen the argument that the four groups of identified cells are indeed neurosecretory.  相似文献   

5.
应用xMAP液念芯片多重快速检测四种病原微生物的研究   总被引:3,自引:0,他引:3  
目的:建立一种多重、快速、特异性好、灵敏度高的病原微生物检测方法。方法:根据GenBank数据库中的小肠结肠炎耶尔森氏菌、单核细胞增生性李斯特菌、产气荚膜梭菌、鼠疫耶尔森氏菌基因序列,分别针对ail、hly、cpe、3a基因设计4对引物和4条探针。通过重叠PCR扩增各目的基因并构建重组质粒,以该重组质粒DNA为模板,通过多重PCR同时扩增上述4个基因,建立xMAP液态芯片检测技术,在此基础上对标准菌株基因组DNA进行检测并验证该方法的特异性和敏感性。结果:xMAP液态芯片对质粒DNA和标准菌株基因组DNA的检测结果与多重PCR结果一致。该方法能在3.5 h内同时完成对4种病原菌的检测,特异性好,且敏感性要高于PCR方法,灵敏度最高可达200CFU/ml。结论:xMAP液态芯片技术是病原微生物的多重快速检测的新方法,具有很好的应用价值和前景。  相似文献   

6.
目的:建立一种多重、快速、特异性好、灵敏度高的病原微生物检测方法。方法:根据GenBank数据库中的小肠结肠炎耶尔森氏菌、单核细胞增生性李斯特菌、产气荚膜梭菌、鼠疫耶尔森氏菌基因序列,分别针对ail、hly、cpe、3a基因设计4对引物和4条探针。通过重叠PCR扩增各目的基因并构建重组质粒,以该重组质粒DNA为模板,通过多重PCR同时扩增上述4个基因,建立xMAP液态芯片检测技术,在此基础上对标准菌株基因组DNA进行检测并验证该方法的特异性和敏感性。结果:xMAP液态芯片对质粒DNA和标准菌株基因组DNA的检测结果与多重PCR结果一致。该方法能在3.5 h内同时完成对4种病原菌的检测,特异性好,且敏感性要高于PCR方法,灵敏度最高可达200CFU/ml。结论:xMAP液态芯片技术是病原微生物的多重快速检测的新方法,具有很好的应用价值和前景。  相似文献   

7.
Scutella separated from germinating grains of barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) took up the four amino acids and the three peptides tested from incubation media. The uptake of amino acids by wheat scutella was similar to that of barley scutella and was via at least four uptake systems: two nonspecific amino acid uptake systems, one system specific for proline, and another system specific for basic amino acids. The scutellum of rice apparently has two nonspecific systems and a system specific for the basic amino acids, but the proline-specific system is lacking. The scutellum of maize seems to have the same systems as the scutellum of rice, but one (or both) of the nonspecific systems differs from that of the other species studied in taking up arginine only slowly. No great differences were observed in the uptake of peptides in the four species studied. The rates of uptake of different amino acids and peptides were of the same order of magnitude in the four cereals. The fact that carboxypeptidase activities in the endosperms of wheat and barley are 20-to 100-fold higher than those in rice and maize, does thus not seem to be reflected in the uptake properties of the scutella.  相似文献   

8.
Genetic differentiation among eight color types of the freshwater goby,Rhinogobius brunneus, from the western part of Japan was investigated by using electrophoretic methods. Four sympatric types (Cross-band, Dark, Cobalt and Large-Dark (A) types) did not share alleles at between one and six loci out of 12 loci tested. No hybrid specimens were found among these types. The average genetic distances among these four types ranged from 0.13 to 0.72, which fall within the range of values among congeneric species of fishes. The average genetic distances among the other four types, Large-Dark (B), Orange, Shinji-Lake and Boso types, were only 0.01 to 0.03, and fall within the range of values among conspecific populations. These results suggest that the former four types are clearly discrete species and the latter four types may be considered as intraspecific variations of a fifth species.  相似文献   

9.
This article examines the origin of life on Earth and its connection to the Superstring Theory, that attempts to explain all phenomena in the universe (Theory of Everything) and unify the four known forces and relativity and quantum theory. The four forces of gravity, electro-magnetism, strong and weak nuclear were all present and necessary for the origin of life on the Earth. It was the separation of the unified force into four singular forces that allowed the origin of life.  相似文献   

10.
The ruminant digestive system harbors a complex gut microbiome, which is poorly understood in the case of the four stomach compartments of yak. High-throughput sequencing and quantitative PCR were used to analyse microbial communities in the rumen, reticulum, omasum, and abomasum of six domesticated yak. The diversity of prokaryotes was higher in reticulum and omasum than in rumen and abomasum. Bacteroidetes predominated in the four stomach compartments, with abundance gradually decreasing in the trend rumen > reticulum > omasum > abomasum. Microorganism composition was different among the four compartments, all of which contained high levels of bacteria, methanogens, protozoa and anaerobic fungi. Some prokaryotic genera were associated with volatile fatty acids and pH. This study provides the first insights into the microorganism composition of four stomach compartments in yak, and may provide a foundation for future studies in this area.  相似文献   

11.
L Giri  A Franz  J Dijk 《Biochemistry》1979,18(12):2520-2525
Proteins L1, L9, L25, and L30, purified by a nondenaturing method from the 50S ribosomal subunit of Escherichia coli A19, have been characterized. The four proteins were studied under conditions which resemble those used for reconstitution experiments. These proteins have S020,W values of 2.0 S, 1.8 S, 1.8 S, and 1.0 S and D20,W values of 8.4 X 10(-7), 9.0 X 10(-7), 14.0 X 10(-7), and 15.0 X 10(-7) cm2/S. Apparent specific volumes at 20 degrees C are 0.738, 0.733, 0.700, and 0.735 mL/g for the four proteins. The respective molecular weights determined by sedimentation equilibrium are 25 000, 17 300, 12 000, and 6500. The intrinsic viscosity values for the four proteins are 4.0, 5.5, 3.6, and 3.2 mL/g. From these hydrodynamic parameters L1 and L9 appear to have globular or at most only slightly elongated shapes, whereas L25 and L30 appear to be definitely globular.  相似文献   

12.
Lysosomal enzymes require a mannose 6-phosphate recognition marker, constructed on asparagine-linked oligosaccharide chains, for targeting to lysosomes. We have identified the glycosylation sites of human beta-hexosaminidase B and have determined the influence of individual oligosaccharides on the phosphorylation, lysosomal targeting, and catalytic activity of the enzyme. The five potential glycosylation sites of the hexosaminidase beta-chain were modified individually by site-directed mutagenesis, and the constructs were expressed in COS 1 cells. By this analysis, we determined that four of the five potential sites were glycosylated. Two of the four oligosaccharides were preferentially phosphorylated. The absence of these two preferentially phosphorylated oligosaccharides resulted in greatly reduced amounts of the lysosomal form of the enzyme with increased secretion into the medium. The catalytic activity of beta-hexosaminidase B was not significantly altered by the absence of individual oligosaccharides suggesting the folding and assembly of the enzyme was not disrupted.  相似文献   

13.
A survey of the terrestrial tardigrades inhabiting growths of algae, lichens and mosses in the Vestfold Hills, Antarctica, was carried out at 11 and 35 sites during the austral summers of 1980 and 1982, respectively. In all, 24 species of plants were collected from which four genera and four species of Tardigrada were recovered. A key to the tardigrades of the area is presented. The distribution and associational patterns of the tardigrades are discussed in the context of other studies of antarctic Tardigrada.  相似文献   

14.
We present results on the seasonality of death in four communes of the Val di Scalve (Bergamo Pre-Alps, Lombardia, Italy). The seasonality is remarkable in all four localities and also in both halves of the century examined (1889-1988). In particular, the mortality peaks during the cold season.  相似文献   

15.
16.
Abstract Eight families of Symphyta for the Western Hemisphere south of the United States are reviewed: Xyelidae (one genus, two species), Pamphiliidae (one genus, four species), Cimbicidae (five genera, nine species), Diprionidae (three genera, thirteen species), Xiphydriidae (four genera, seventeen species), Siricidae (six genera, nine species), Orussidae (five genera, twelve species), and Cephidae (one genus, one species). New taxa are Acantholyda nigrostigmata (Pamphiliidae); Zadiprionfalsus, Neodiprion bicolor, N.equalis, N.omosus (Diprionidae); Derecyrta circularis, Steirocephala lateralba (Xiphydriidae); Sirotremex, S.flammeus (Siricidae); and Ophrynopus depressatus, O.plaumanni (Orussidae). Lopesiana is a new name for Lopesia Conde (Cimbicidae). Three new combinations and six new synonyms are proposed. The Xyelidae, Pamphiliidae, Diprionidae, Siricidae and Cephidae are primarily northern groups with southern extensions into Mexico, Central America and/or Cuba. The Cimbicidae, Xiphydriidae and Orussidae are more generally distributed throughout the neotropics. Keys to families, genera and species are provided.  相似文献   

17.
Luteal progesterone was removed by an injection of prostaglandin F(2alpha) or bilateral ovariectomy on Day 12 of pregnancy in pony mares. The embryonic vesicle remained mobile in the uterus until loss occurred on Days 13, 13, 15, or 19 in four prostaglandin-treated mares and Days 15, 17, 19, or 26 in four ovariectomized mares. Exogenous progesterone given daily, starting on Day 12, maintained pregnancy until Day 40 in five of five prostaglandin-treated and three of four ovariectomized mares. During two-hour mobility trials on Day 14, embryonic vesicles in mares without luteal or exogenous progesterone (n = 9) moved to a different uterine segment less frequently (mean number of location changes per two-hour trial: 7.2 +/-1.0 vs 10.4 +/-1.1, P < 0.05) and were observed more often in the uterine body (14.9 +/-2.9 vs 8.9 +/-1.3, P < 0.10) compared to vesicles in mares with a progesterone influence (n = 15). Of mares that still had a vesicle present on Day 18, fixation occurred by Day 17 in all (12 12 ) mares under the influence of luteal or exogenous progesterone but failed to occur in the three mares that were not under progesterone influence. Progesterone replacement was started on Day 16 in three mares that received prostaglandin F(2alpha) on Day 12 and still had a vesicle on Day 16. The vesicle was maintained and continued to develop in all three mares, indicating that the vesicles were viable four days after PGF(2alpha) treatment. However, fixation tended to be delayed (P < 0.15) and orientation of the embryo proper was altered (P < 0.005) compared to mares that were continuously under the influence of progesterone. The results demonstrated the importance of luteal progesterone to mobility, fixation, orientation, and survival of the embryonic vesicle.  相似文献   

18.
Developmental features of thoracic intervertrebral discs and their association in the adult with other vertebral structures were investigated in four species. The human anulus fibrosus, nucleus pulposus, and intra-articular ligaments were compared to those of the fetal rhesus monkey, mouse, and kitten. Photomicrographs of transverse sections of intervertebral discs document the presence of intra-articular ligaments in fetuses of these four species. Both transverse and sagittal sections of kittens were used to identify the intercapital ligament as it differentiated from the dorsal part of the intra-articular ligament. Relatively frequent dorsal herniation of the thoracic nucleus pulposus in humans may be due to the vestigial nature of the human intra-articular ligament. Quadrupeds have well-developed intra-articular ligaments, which explains anatomically the paucity of dorsal protrusions of the nucleus pulposus into the vertebral canal in the thoracic region of the cat and mouse when compared to the human. The intra-articular ligament was closely associated with the developing prenatal mammalian intervertebral disc in the four species studied, and this relationship and its surgical importance are described.  相似文献   

19.
The aim of this study was to examine the bacterial composition of high latitude soils from the Darwin–Hatherton glacier region of Antarctica. Four soil pits on each of four glacial drift sheets were sampled for chemical and microbial analyses. The four drifts—Hatherton, Britannia, Danum, and Isca—ranged, respectively, from early Holocene (10 ky) to mid-Quaternary (ca 900 ky). Numbers of culturable bacteria were low, with highest levels detected in soils from the younger Hatherton drift. DNA was extracted and 16S rRNA gene clone libraries prepared from samples below the desert pavement for each of the four drift sheets. Between 31 and 262 clones were analysed from each of the Hatherton, Britannia, and Danum drifts. Bacterial sequences were dominated by members of the phyla Deinococcus-Thermus, Actinobacteria, and Bacteroidetes. Culturable bacteria, including some that clustered with soil clones (e.g., members of the genera Arthrobacter, Adhaeribacter, and Pontibacter), belonged to Actinobacteria and Bacteroidetes. The isolated bacteria are ideal model organisms for genomic and phenotypic investigations of those attributes that allow bacteria to survive and/or grow in Antarctic soils because they have close relatives that are not tolerant of these conditions.  相似文献   

20.
Seasonal variation of the biomass of plankton in Lake Yunoko, a eutrophic lake in Japan at an altitude of 1478 in, was followed by measuring simultaneously the quantities of chlorophyll, protein, RNA and DNA in water samples harvested from different depths at a definite site in different seasons of a year. The contents of the four cellular constituents and the sum of them in a given water column showed characteristic seasonal changes during the year. Various ratios derived from the four contents were grouped into two distinct types; one is the winter-spring type and the other the summer-autumn type. It was found that the sum of the four contents and the ratio of the protein-content to the RNA-content were quantitatively related to the chlorophyll-content of the water. Based on the assumption that a certain water sample contained only photosynthetic plankton, analyses were made to estimate the proportions of photosynthetic and non-photosynthetic plankton to the total planktonic mass, the growth rates of these plankton, and the net productivity of the lake.  相似文献   

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