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Expression of an antibody Fv fragment in myeloma cells 总被引:5,自引:0,他引:5
The antigen binding site on antibodies is fashioned by loops at the tips of the beta-sheet framework of both heavy and light chain variable domains. A heterodimer of both variable domains (Fv fragment), incorporating loops from an anti-lysozyme antibody, was expressed and secreted from myeloma cells in good yield (8 mg/l in supernatant from roller bottles), and shown to bind lysozyme. The two subunits were found to be in dynamic equilibrium but are overwhelmingly associated at neutral pH. The small size of Fv fragments (25 x 10(3) Mr) make them attractive for structural studies, in vivo imaging, and therapy. 相似文献
465.
Comparative genome analysis enables the sites of centromeres, telomeres and nucleolar organiser regions to be aligned with
borders that define the sets of linked genes conserved across the cereal genomes. This provides a basis for studying cereal
genome evolution. 相似文献
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O6-methylguanine-DNA methyltransferase in wild-type and ada mutants of Escherichia coli. 总被引:16,自引:7,他引:9 下载免费PDF全文
O(6)-Methylguanine-DNA methyltransferase is induced in Escherichia coli during growth in low levels of N-methyl-N'-nitro-N-nitrosoguanidine. We have developed a sensitive assay for quantitating low levels of this activity with a synthetic DNA substrate containing 3H-labeled O(6)-methylguanine as the only modified base. Although both wild-type and adaptation-deficient (ada) mutants of E. coli contained low but comparable numbers (from 13 to 60) of the enzyme molecules per cell, adaptation treatment caused a significant increase of the enzyme in the wild type but not in the ada mutants, suggesting that the ada mutation is in a regulatory locus and not in the structural gene for the methyltransferase. 相似文献
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Poor resolution, retarded progress of DNA through gels, and variable sizing of DNA fragments between and within gels hinder
accurate genotyping of some simple sequence length polymorphism (SSLP) markers with the Perkin Elmer Applied Biosystems 377
Sequenator. These problems are similar to renaturation related problems observed in DNA sequencing gels. PCR products especially
susceptible to these problems are shown to have higher melting temperatures (Tm) than others. Gels containing increased concentrations of denaturants allow greater accuracy in allelic discrimination. This
is especially beneficial where quantification is necessary.
Received: 7 February 2000 / Accepted: 16 March 2000 相似文献
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