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151.
VNP减弱NE刺激的心肌细胞c-fos表达 总被引:2,自引:1,他引:2
于军 《中国应用生理学杂志》2000,16(2):141-144
目的:研究血管利钠肽(VNP)对去甲贤上腺素(NE)刺激的心肌细胞c-fos表达的影响。方法:分离纯化SD乳鼠心肌细胞,随机分为四组:对照组、NE组、VNP组和VNP+NE组。以免疫组织化学染色方法观察各组c-fos的表达情况,采用放射免疫方法测定了细胞内cGMP水平。结果:NE(10^-6mol/L)可以显著升高Fos样免疫阳性细胞数及染色强度(P〈0.05,vs对照组),VNP(10^-7mo 相似文献
152.
Recent analysis of alpha helices in protein crystal structures, available in literature, revealed hydrated alpha helical segments in which, water molecule breaks open helix 5-->1 hydrogen bond by inserting itself, hydrogen bonds to both C=O and NH groups of helix hydrogen bond without disrupting the helix hydrogen bond, and hydrogen bonds to either C=O or NH of helix hydrogen bond. These hydrated segments display a variety of turn conformations and are thought to be 'folding intermediates' trapped during folding-unfolding of alpha helices. A role for reverse turns is implicated in the folding of alpha helices. We considered a hexapeptide model Ac-1TGAAKA6-NH2 from glyceraldehyde 3-phosphate dehydrogenase, corresponding to a hydrated helical segment to assess its role in helix folding. The sequence is a site for two 'folding intermediates'. The conformational features of the model peptide have been investigated by 1H 2D NMR techniques and quantum mechanical perturbative configuration interaction over localized orbitals (PCILO) method. Theoretical modeling largely correlates with experimental observations. Based upon the amide proton temperature coefficients, the observed d alpha n(i, i + 1), d alpha n(i, i + 2), dnn(i, i + 1), d beta n(i, i + 1) NOEs and the results from theoretical modeling, we conclude that the residues of the peptide sample alpha helical and neck regions of the Ramachandran phi, psi map with reduced conformational entropy and there is a potential for turn conformations at N and C terminal ends of the peptide. The role of reduced conformational entropy and turn potential in helix formation have been discussed. We conclude that the peptide sequence can serve as a 'folding intermediate' in the helix folding of glyceraldehyde 3-phosphate dehydrogenase. 相似文献
153.
PENG JunYa ZHANG Ran CUI YiTong LIU HaoDong ZHAO XiaoXin HUANG Lei HU MingXu YUAN XiaoXi MA BenYu MA XiaoWei TAKASHI Ueno MASAAKI Komatsu LIANG XingJie YU Li 《中国科学:生命科学英文版》2014,57(1):59-68
Autophagy is an evolutionarily conserved lysosome-based degradation process.Atg5 plays a very important role in autophagosome formation.Here we show that Atg5 is required for biogenesis of late endosomes and lysosomes in an autophagy-independent manner.In Atg5 cells,but not in other essential autophagy genes defecting cells,recycling and retrieval of late endosomal components from hybrid organelles are impaired,causing persistent hybrid organelles and defective formation of late endosomes and lysosomes.Defective retrieval of late endosomal components from hybrid organelles resulting from impaired recruitment of a component of V1-ATPase to acidic organelles blocks the pH-dependent retrieval of late endosomal components from hybrid organelles.Lowering the intracellular pH restores late endosome/lysosome biogenesis in Atg5 cells.Our data demonstrate an unexpected role of Atg5 and shed new light on late endosome and lysosome biogenesis. 相似文献
154.
Ion beams have been widely usedinthe semiconduc-tor industryand appliedfor surface modificationof materi-als since the1970s,while nobody had discussed howthese ion beams could be used in genetic modification inbiological science,evenfewpeople paid attentionto bio-logical effects induced byion beamandtheir possible usein genetics.In1986,Yu et al.have discovered the ge-netic effects in rice mediated by low energy ions[1—5].Since thenion beamradiation has been widely usedtoim-prove crops and the performance of... 相似文献
155.
WANG Zhichong GE Jian HUANG Bing GAO Qianying LIU Bingqian WANG Linghua YU Ling FAN Zhigang LU Xiaoming & LIU Jingbo Zhongshan Ophthalmic Center Sun Yat-sen University Guangzhou China 《中国科学:生命科学英文版》2005,48(5):471-480
Embryonic stem (ES) cell lines were first generated from mouse blastocysts by culturing inner cell mass (ICM) from pre-implantation embryos on feeder lay-ers[1,2]. ES cells have an extensive capacity to preserve their pluripotent nature of self renewing even after genetic manipulation, selection and cryopreservasion in vitro. Many experiments have demonstrated that ES cells have an ability to differentiate into various kinds of cells and tissues naturally originated from all three embryonic… 相似文献
156.
The mammalian glycosylphosphatidylinositol (GPI) anchor consists of three mannoses attached to acylated GlcN-(acyl)PI to form Man(3)-GlcN-(acyl)PI. The first of the three mannose groups is attached to an intermediate to generate Man-GlcN-(acyl)PI by the first mannosyltransferase (GPI-MT-I). Mammalian and protozoan GPI-MT-I have different substrate specificities. PIG-M encodes the mammalial GPI-MT-I which has 423 amino acids and multiple transmembrane domains. In this work we cloned PIG-M homologues from humans, Plasmodium falciparum (PfPIG-M), and Saccharomyces cerevisiae (GPI14), to test whether they could complement GPI-MT-I-deficient mammalian cells, since this biosynthetic step is likely to be a good target for selective screening of inhibitors against many pathogenic organisms. PfPIG-M partially restored cell surface expression of the GPI-anchored protein CD59 in PIG-M deficient mammalian cells, and first mannose transfer activity in vitro; however, this was not the case for GPI14. 相似文献
157.
Sato B Katagiri YU Miyado K Akutsu H Miyagawa Y Horiuchi Y Nakajima H Okita H Umezawa A Hata J Fujimoto J Toshimori K Kiyokawa N 《Biochemical and biophysical research communications》2007,364(4):838-843
The monoclonal antibody 6E2 raised against the embryonal carcinoma cell line NCR-G3 had been shown to also react with human germ cells. Thin-layer chromatography (TLC) immunostaining revealed that 6E2 specifically reacts with sialosylglobopentaosylceramide (sialylGb5), which carries an epitope of stage-specific embryonic antigen-4 (SSEA-4), known as an important cell surface marker of embryogenesis. The immunostaining of mouse preimplantation embryos without fixation showed that the binding of 6E2 caused the clustering and consequent accumulation of sialylGb5 at the interface between blastomeres. These results suggest that SSEA-4 actively moves on the cell surface and readily accumulates between blastomeres after binding of 6E2. 相似文献
158.
159.
大鳞副泥鳅ZZ/ZW型性别决定的细胞遗传学证据 总被引:12,自引:1,他引:12
大鳞副泥鳅是鲤形目、鳅科的鱼类。其2n数为48,核型组成为12m+4sm+32 t(雄性),11m+5sm+32t(雌性)。根据银染带和C带特征分析,证实大鳞副泥鳅为ZZ/ZW型性别决定。Z染色体为中部着丝粒染色体,在其长臂端部有Ag -NOR存在。 W染色体为亚中部着丝粒染色体,在其长臂末端也有Ag-NOR存在,同时还有一深染的居间C带,这是W染色体独有的带纹特征。
Abstract:Paramisgurnus dabryanus belongs to Cypriniformes,Cobitidae.Its 2n is 48.The karyotype formula is 12m+4sm+32t(in male),11m+5sm+32t(in female).According to the Ag-NORs band and C-band patterns,we consider that its sex determination is of ZZ/ZW type.The Z chromosome is a metacentric one with Ag-NORs located on its arm end.The W chromosome is a submetacentric with Ag-NORs located on the terminal of its long arm.There is a darkly stained C-band on the long arm of W chromosome.This band is a characteric of the W chromosome. 相似文献
160.
Benzoylecgonine is a major metabolite of cocaine. We generated hybridoma cells (C1303) producing anti-benzoylecgonine monoclonal
antibody (mAb) with a single-chain variable fragment (scFv) and an antigen-binding domain from the C1303 cells. Genes encoding
an scFv antibody and constant region (Fc) were amplified from a cDNA library of C1303 cells using PCR. The two frameworks
built for scFv and scFv-Fc consisted of HL [(heavy chain variable region, VH) — linker — (light chain variable region, VL)] and HL-Fc, respectively. A 45 base-pair-long sequence encoding (Gly4-Ser)3 was used as the linker, and the mouse IgG1 constant region sequence (225 amino acids) was used as the Fc domain. These two
types of recombinant Abs were determined to be 750 bp in length (which corresponds to a 30 kDa protein) in the HL and 1,432
bp in length (which corresponds to a 65 kDa protein) in the HL-Fc, respectively. The parental Ab and HL-Fc affinities against
benzoylecgonine were measured by ELISA and found to be nearly equal to the Ab concentration. We were also able to measure
HL affinity using an agarose diffusion assay (Ouchterlony test). The affinity of the recombinant single-chain antibody against
benzoylecgonine was sufficiently comparable to that of the parent antibodies to be used for the immunodetection of specific
drug compounds or the detoxification of drug abusers by immunotherapy. 相似文献