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排序方式: 共有176条查询结果,搜索用时 15 毫秒
1.
Rabbit Ig kappa 1b6 gene structure 总被引:1,自引:0,他引:1
K L Dreher V Asundi B Wolf L Bruggeman 《Journal of immunology (Baltimore, Md. : 1950)》1990,145(1):325-330
Previous studies employing Southern blot analyses have detected multiple kappa-homologous sequences within EcoRI-digested DNA isolated from kappa 1b6 homozygous rabbits and kappa 1b6 L chain secreting RMH H158 cell line. These results are very unexpected because the published partial protein sequence for the kappa 1b6 C region is incompatible with an EcoRI restriction endonuclease recognition sequence at the nucleotide level for this allotype. To determine their identity, the kappa-homologous sequences were isolated from DNA extracted from a kappa 1b6 L chain secreting RMH H158 cell line by molecular cloning. Structural analyses demonstrated these sequences to contain genetic information encoding the majority of the kappa 1b6 L chain gene locus. The protein sequence deduced from the kappa 1b6 C region gene was shown to differ from the published partial kappa 1b6 C region protein sequence at five amino acid positions. One of these differences results in a glycine to serine interchange that introduces an EcoRI restriction endonuclease recognition site within the kappa 1b6 C region gene. Subsequent genomic Southern blot analyses confirmed this structural assignment. Based on these data, the EcoRI-sensitive kappa-homologous fragments present within the genomes of the RMH H158 cell line and kappa 1b6 homozygous rabbits represent the nominal kappa 1 gene and not an alternative kappa isotype or kappa pseudogene. Rabbit Ig kappa 1 allelic nucleotide sequence homology comparisons have shown the isolated kappa 1b6 J-C gene locus to display common structural features previously identified in other kappa 1 alleles. 相似文献
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Serologic and structural characterization of immunoglobulin chains secreted by rabbit-mouse hybridomas 总被引:3,自引:0,他引:3
M L Yarmush F T Gates K L Dreher T J Kindt 《Journal of immunology (Baltimore, Md. : 1950)》1981,126(6):2240-2244
Serologic and primary structural analyses of Ig chains secreted by several rabbit-mouse hybridomas have shown that these hybrid cells produce heavy (H) or light (L) chains identical to those isolated from rabbit sera. Two of the cell lines (7D2, 7D6) secreted rabbit H chains with a m.w. of 55,000 each of which expressed a full complement of variable and constant region allotypes (a3, d11, e15). These apparently normal rabbit H chains were secreted in a complex with a m.w. about 130,000, and serologic studies indicated that this complex contained a covalently linked mouse kappa L chain. Two other cell lines (4C1, 12F2) produced allotype b4 L chains with m.w. of 23,000 and 25,000, and a third (1D4P5) produced an allotype b5 L chain with a m.w. of 23,000. Serologic analyses indicated that the allotypes on these chains are equivalent to those expressed by normal rabbit Ig molecules. Partial amino acid sequence data obtained for the L chain products showed them to be typical of rabbit L chains, and to be significantly different from mouse L chains. 相似文献
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A method is presented for the isolation of bacteriophage lambda DNA and the rapid identification of large cDNA inserts within crude phage lysates. The primary screening of a lambda gt11 cDNA library with a 32P-radiolabeled cDNA probe yielded 21 putative positive clones. A phage "spot-blot" analysis was employed to quickly screen these potential recombinants. This eliminated 9 of the 21 clones as the result of false positive signals. The remaining 12 recombinant phage were amplified on agarose-based media, and phage DNA was isolated using a modified plate lysate procedure. The DNA thus obtained from these crude lysates could be easily digested with EcoRI and examined by Southern blot analysis. The resulting blot was hybridized with the same cDNA probe used in the initial screening of the library. Thus, two clones harboring the longest cDNA insert were identified from a mixed phage population and were subsequently plaque purified. The procedure is rapid, sensitive, reproducible, inexpensive and allows the processing of several clones at once without sacrificing the quality or yields of the DNA preparation. Furthermore, the method obviates the need for plaque purifying all the positives obtained from the initial screening of a cDNA library. 相似文献
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Down-regulation of phorbol diester binding to NG115-401L neuronal cells is dependent on structure, concentration and time 总被引:2,自引:0,他引:2
The down-regulation of [3H]PDBu binding to a neural cell line, NG115-401L, has been examined in response to two biologically active phorbol diesters, PDBu and PMA. Chronic treatment with PDBu or PMA causes a concentration- and time-dependent loss of specific [3H]PDBu binding. The action of PMA is biphasic with respect to both concentration and time dependence. 相似文献
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Summary A complex, higly sulphated glucoxylomannogalactan has been extracted in a yield of about 1% dry weight fromC. simpliciuscula. This polysaccharide is similar in composition to sulphated polysaccharides previously isolated from otherCaulerpa species (Mackie andPercival, 1961). The most likely location of this compound in the unwounded cell is in the vacuole. This polysaccharide appears as the major component in wound plugs, forming a viscoelastic barrier between the protoplasm and the external environment. The properties of the sulphated polysaccharide were studied in an effort to understand the physiology and mechanism of wound plug formation. 相似文献
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Emilie M. M. Santos Wiro J. Niessen Albert J. Yoo Olvert A. Berkhemer Ludo F. Beenen Charles B. Majoie Henk. A. Marquering MR CLEAN investigators 《PloS one》2016,11(1)
Background and Purpose
In acute ischemic stroke (AIS) management, CT-based thrombus density has been associated with treatment success. However, currently used thrombus measurements are prone to inter-observer variability and oversimplify the heterogeneous thrombus composition. Our aim was first to introduce an automated method to assess the entire thrombus density and then to compare the measured entire thrombus density with respect to current standard manual measurements.Materials and Method
In 135 AIS patients, the density distribution of the entire thrombus was determined. Density distributions were described using medians, interquartile ranges (IQR), kurtosis, and skewedness. Differences between the median of entire thrombus measurements and commonly applied manual measurements using 3 regions of interest were determined using linear regression.Results
Density distributions varied considerably with medians ranging from 20.0 to 62.8 HU and IQRs ranging from 9.3 to 55.8 HU. The average median of the thrombus density distributions (43.5 ± 10.2 HU) was lower than the manual assessment (49.6 ± 8.0 HU) (p<0.05). The difference between manual measurements and median density of entire thrombus decreased with increasing density (r = 0.64; p<0.05), revealing relatively higher manual measurements for low density thrombi such that manual density measurement tend overestimates the real thrombus density.Conclusions
Automatic measurements of the full thrombus expose a wide variety of thrombi density distribution, which is not grasped with currently used manual measurement. Furthermore, discrimination of low and high density thrombi is improved with the automated method. 相似文献10.
In vivo and in vitro requirements for the formation of cytochrome b(6) were examined to analyze the mechanisms of transmembrane b-type cytochrome formation. After heterologous expression of spinach cytochrome b(6), formation of the holo-cytochrome was observed within the E. coli inner membrane. The transmembrane orientation of cytochrome b(6) appeared not to be critical for heme binding and holo-cytochrome formation. Furthermore, in vitro reconstitution of cytochrome b(6) was possible under oxidizing as well as under reducing conditions. Taken together these observations strongly indicate that transmembrane b-type cytochromes can spontaneously assemble in vitro as well as in a membrane. 相似文献