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71.
The power of heteronuclear NMR spectroscopy to study macromoleculesand their complexes has been amply demonstrated over the last decade. Theobstacle to routinely applying these techniques to the study of DNA has beenthe synthesis of 13C,15N-labeled DNA. Here wepresent a simple and efficient method to generate isotope-labeled DNA forNMR studies that is as easy as that for isotope labeling of RNA. The methodwas used to synthesize a uniformly13 C,15N-labeled 32-nucleotide DNA that binds tohuman basic fibroblast growth factor with high affinity and specificity.Isotope-edited experiments were applied to the13 C,15N-labeled DNA bound to unlabeled protein,and the 13 C,15N-labeled DNA was also examined incomplex with 15N-labeled protein. The NMR experiments showthat the DNA adopts a well-defined stable structure when bound to theprotein, and illustrate the potential of13 C,15N-labeled DNA for structural studies ofDNA–protein complexes. 相似文献
72.
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74.
Callus cultures and cell suspension cultures derived from Ginkgo biloba L. leaves produced ginkgolidc B. In cell suspension cultures, the production reached a maximum by the 13th day of subculture and followed by a sharp decrease. The medium of Murashige and Skoog induced the highest ginkgolide B content in cultures while the medium of Schenk and Hildebrandt promoted cell growth. For the maximal production of ginkgolide B, cells were cultured in Murashige and Skoog medium modified to contain 1.0 mg/l of -naphthaleneacetic acid, 0.1 mg/1 of kinetin, 30 g/1 sucrose and 1.25 mM potassium phosphate with a molar ratio of ammonium to nitrate ions of 1 3.Abbreviations B5
Gamborg et al (1968) medium
- GKB
Ginkgolide B
- MS
Murashige and Skoog (1962) medium
- NAA
-naphthaleneacetic aicd
- SH
Schenk and Hildebrandt (1972) medium 相似文献
75.
鱼腥藻HB1017株化能异养生长的研究 总被引:5,自引:1,他引:4
以葡萄糖和蔗糖为碳源,检测了六株(种)鱼腥藻的化能异养生产能力。其中鱼腥藻HB1017株化能异养生长较快,鱼腥藻HB0株化能异养生长缓慢,其余四种鱼腥藻不能进行化能异养生长。鱼腥藻HB1017株能利用果糖、葡萄糖、蔗糖为底物进行化能异养生长,但生长速率依次递减,差别显著。8磅湿热灭菌的果糖和蔗糖,与过滤灭菌的相比,只能维持低得多的化能异养生长速率。然而,8磅湿热灭菌的葡萄糖能维持比过滤法灭菌的高得 相似文献
76.
77.
生态环境对白芷产量质量的影响 总被引:1,自引:0,他引:1
生态环境对白芷产量质量的影响陈兴福,丁德蓉,刘岁荣,卢进,黄文秀(四川省中医药研究院药物种植研究所,南川648408)EffectofEco-EnvironmentonDahurianAngelicaYieldandItsQuality¥ChenXi... 相似文献
78.
付里叶变换红外光谱研究短杆菌肽A及其在脂双层中加Na~+前后的构象变化 总被引:1,自引:0,他引:1
用FTIR光谱研究了短杆菌肽A(GA)在固态,组装入DPPC脂持体,以及Na+结合状态的构象变化。固态时酰胺Ⅰ带峰位于163cm-1左右,且在1685cm-1处有一肩峰;酰胺Ⅱ带位于1530cm1左右,整个分子为反平行的β螺旋结构,为非通道构象。当GA组装入脂质体后,酰胺Ⅰ带仍位于1633cm-1,但1685cm-1的肩峰消失,酰胺Ⅱ带移至1550cm-1,分子间氢键转变为分子内氢键,二聚体从原来的双股螺旋变为头-头相连的单股螺旋,是GA的膜内通道构象。Na+的结合并不改变GA的骨架结构,但通过对酰胺Ⅰ带的拟合分析发现:加Na+后位于1644cm-1的无规结构含量减少10%,而有序结构增加,提示部分无视结构可能有一种“门”的作用:当无离子通过时为“关闭”状态,当与离子结合后即“打开”,这样通过构象的改变来实现其通道功能。 相似文献
79.
We have generated four xenogeneic rat antimouse IgG3 monoclonal antibodies recognizing at least three different antigenic determinants (epitopes) on BALB/c IgG3 molecules. These antibodies were used in solid-phase blocking radioimmunoassays for detection of the epitopes in sera of 40 inbred strains and 134 wild mice. These antibodies detect genetic polymorphism of IgG3 isotype among wild mice even though there is no polymorphism found among 40 inbred strains tested (except X-chromosome-linked immunodeficient CBA/N strain which lacks IgG3 molecules). An IgG3 variant was also isolated from hybridomas derived from Mus spretus.Abbreviations
Igh-C
immunoglobulin heavy chain constant region
- PVC
polyvinyl chloride
- RIA
radioimmune assay
- ELISA
enzyme linked immunosorbent assay 相似文献
80.
Human chromosomal assignments for 14 argininosuccinate synthetase pseudogenes: cloned DNAs as reagents for cytogenetic analysis 总被引:13,自引:6,他引:7
T S Su R L Nussbaum S Airhart D H Ledbetter T Mohandas W E O''Brien A L Beaudet 《American journal of human genetics》1984,36(5):954-964
There are multiple, processed, dispersed pseudogenes for human argininosuccinate synthetase. Chinese hamster X human somatic cell hybrids were used to map DNA fragment groups corresponding to the single expressed gene and 14 pseudogene loci. Each chromosomal assignment was confirmed using hybrids containing very few human chromosomes and/or by demonstrating monosomic or trisomic dosage in human cell lines with chromosomal abnormalities. Pseudogenes were mapped to chromosomes 2cen-p25, 3q12-qter, 4q21-qter, 5 (two loci), 6, 7, 9p13-q11, 9q11-q22, 11q, 12, Xp22-pter, Xq22-q26, and Ycen-q11. DNA fragments from the expressed gene were mapped to 9q34-qter in agreement with the previous assignment for enzyme activity. A high-frequency restriction fragment length polymorphism mapped to 9q11-q22. The analyses emphasized the feasibility of using chromosomally abnormal human cell lines for confirmation and regionalization of gene-mapping assignments made using somatic-cell hybrids. Conversely, cloned DNA probes, once mapped and characterized, can be very valuable for determining the chromosomal composition of interspecies hybrids and the dosage of loci in human cells. The argininosuccinate synthetase cDNA is a convenient reagent for dosage analysis of 15 human loci on 11 different chromosomes. Improved reagents could be designed that would simplify Southern blot patterns by eliminating overlapping DNA fragments and providing a single DNA fragment for each locus. 相似文献