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81.
Disuccinimidyl suberate (DSS) intramolecularly cross-linked hemoglobin (Hb) was developed as a novel red blood cell substitute. A multi-angle laser light scattering detector coupled with size exclusion HPLC was applied to determine the molecular weight of the modified Hb. SDS-PAGE was also used as a complement. It was proved that 83.8% of the product was intramolecularly cross-linked Hb with weight-average molecular weights (Mw) of 67.5 kD, 12% was dimeric Hb with Mw of 146.6 kD, and 4.2% was trimeric Hb with Mw of 306.4 kD. The tetramer structure of the cross-linked Hb was stable as shown in size-exclusion chromatography using a mobile phase containing 1 mol/L MgCI2. Analysis by LC-MS demonstrated that the reaction of DSS with Hb mainly took place between the two a subunits within a Hb molecule, resulting in stabilization of the tetramer structure. However, the cross-linking was not site-specific. The P50 of the cross-linked Hb decreased from 21.8 mmHg to 14.3 mmHg, and the Hill coefficient decreased from 2.22 to 1.41. Result of isoelectric focusing showed that the pi of DSS cross-linked Hb was in the range of 4.6-5.2, similar to that of serum albumin. The safety of DSS cross-linked Hb was favored by animal tests on rats and guinea pigs. Exchange transfusion experiment with DSS cross-linked Hb using rats as a model indicated no pressor effect or other significant side effects. The characteristics and properties of DSS cross-linked Hb were also compared with that of diaspirin cross-linked Hb reported in the literature.  相似文献   
82.
Most proterminal regions of human chromosomes are GC-rich and gene-rich. Chromosome 3p is an exception. Its proterminal region is GC-poor, and likely to lose heterozy-gosity, thus causing a number of fatal diseases. Except one gap left in the telomeric position, the proterminal region of human chromosome 3p has been completely sequenced. The detailed sequence analysis showed: (i) the GC content of this region was 38.5%, being the lowest among all the human proterminal regions; (ii) this region contained 20 known genes and 22 predicted genes, with an average gene size of 97.5 kb. The previously mapped gene Cntn3 was not found in this region, but instead located in the 74 Mb position of human chromosome 3p; (iii) the interspersed repeats of this region were more active than the average level of the whole human genome, especially (TA)n, the content of which was twice the genome average; (iv) this region had a conserved synteny extending from 104.1 Mb to 112.4 Mb on the mouse chromosome 6, which was 8% larger in size, not in accordance with the whole genome comparison, probably because the 3pter-p26 region was more likely to lose neocleitides and its mouse synteny had more active interspersed repeats.  相似文献   
83.
Herein, we report the cloning and molecular characterization of a full cDNA encoding a putative plastidic ATP/ADP transporter, designated HtAATP, for Helianthus tuberosus L. The ATP/ADP translocator protein was isolated from the tuber-cDNA library of H. tuberosus for the first time. The predicted HtAATP protein was judged as a plastidic ATP/ADP translocator protein from its high homology at the amino acid sequence level to the two Arabidopsis thaliana plastidic ATP/ADP translocator proteins AATP1 and AATP2 (84.8% and 79.9% identity, respectively). Amino acid sequence analysis of the primary structure of HtAATP revealed that it belonged to the plastidic ATP/ADP transporter family. Hydropathy prediction indicated that HtAATP gene product is a highly hydrophobic membrane protein that contains 10 transmembrane domains to form a spanning topology. Southern blotting analysis showed that the HtAATP gene is a single-copy gene in the H. tuberosus genome. Tissue distribution analysis showed that the HtAATP gene is prominently expressed in sink tissues. A stable expression pattern in tubers at different developmental stages implies an active involvement of HtAATP during carbohydrate formation.  相似文献   
84.
Two New Saponins from Lysimachia capillipes Hemsl.   总被引:1,自引:0,他引:1  
To investigate the saponins from whole plants of Lysimachia capillipes Hemsl., two new saponins, named capilliposide E (1) and capilliposide F (2), were isolated. The structures of the new sa ponins were elucidated as 3 β, 22α-dihydroxy- 16α-acetat-28→ 13 -lactone-oleanane-3 -O- [β-D-glucopyranosyl(1→2)-α-L-arabinpyranoyl]-22-O-β-D-glucopyranoside (1) and 3 β, 22α-dihydroxy- 16α-acetat-28→ 13-1actone-oleanane-3-O- { [β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)]-α-L-arabinpyranoyl }-22-O-βD-glucopyranoside (2). The structures of these compounds were determined by 1D- and 2D-NMR, MS techniques, and chemical methods.  相似文献   
85.
为 调查DYS413(YCAⅢ) 基因座在内蒙古蒙古族人群中的分布情况,为其应用于法医学和人类遗传学研究提供依据,采集了120例内蒙古蒙古族男性无关个体静脉血,EDTA抗凝,用酚-氯仿法抽提DNA,PCR扩增DYS413基因座,6%非变性聚丙烯酰胺凝胶电泳,1‰硝酸银(AgNO3)染色分型。 在120例内蒙古蒙古族男性人群中共检出30个不同的单倍型,其频率介于0.0007至0.01361之间,其HD(单倍型多样性)值为0.94054。表明DYS413基因座在内蒙古蒙古族人群中分布好,对法医学和人类遗传学研究具有重要价值。Abstract: In order to provide the evidence for the application of DYS413(YCAⅢ) locus in forensic medicine and population genetics by investigating its polymorphism in the Mongolians lived in the Inner Mongolia Autonomous Region, China, to collect 120 unrelated male Mongolians’ venous blood, who lived in the Inner Mongolia Autonomous Region, and the blood is anticoagulant with EDTA, then to extract DNA by using the method of phenol-chloroform and amplify the DYS413 locus with PCR. The products were separated with 6% non-denatured polyacrylamide/bisacrylamide gels(19:1) electrophoresis and stained with 1‰ nitrate of silver(AgNO3). There are total 30 different haplotypes in Mongolians, the frequencies are from 0.0007 to 0.01361, the HD(haplotype diversity) is 0.94054. It shows that DYS413 locus is high valuable in the application of forensic medicine and population genetics.  相似文献   
86.
To determine which subtype of α1-adrenergic receptors plays a role in the regulation of blood pressure, with α1A-adrenergic receptor-mediated vasoconstriction in perfused hindlimb as a control, we compared the inhibitory effects of various ai-adrenergic receptor selective antagonists on the vasopressure responses to phenylephrine between the mean arterial pressure and hindlimb perfusion pressure in anesthetized rats. In Normotensive Wistar rats, the results showed that the inhibitory effects (dose ratios of ED50, Dr) of α1-adrenoceptor selective antagonist (prazosin, Dr 13.5±3.6 vs.15.1±4.3, n = 11), α1A-adrenoceptor selective antagonist (5-methyl-urapidil, Dr 2.4±0.9 vs. 3.7±2.3, n = 12; RS-17053, Dr 3.2±1.6 vs. 4.4±3.3, n =12) and α1D-adrenoceptor selective antagonist (BMY7378, Dr 1.9±0.9 vs. 2.2±0.8, n = 8) on phenylephrine- induced increases of perfusion pressure in the autoperfused femoral beds were the same as that in the mean arterial blood pressure in normotensive Wistar rats. The i  相似文献   
87.
Mac-1 (macrophage differentiation antigen asso-ciated with complement three receptor function), alsonamed CD11b/CD18, an adhesion molecule belongingresting leukocytes and at the surface of activated leu-kocytes (macrophages and neutrophils). Mac-1 playsan important role in the migration, chemotaxis and 2 Methodsphagocytosis of leukocytes[1]. Although there have 2.1 Observation of PMA-stimulated Mac-1 traffick-been several reports on the role of Mac-1 in neutrophil ingadh…  相似文献   
88.
黄山地处亚热带季风气候区内,植被丰富多样,为粒毛盘菌等腐生真菌生长提供了适宜的生境,对该地区粒毛盘菌等相关类群资源进行了研究,报道了粒毛盘菌属6个分类单元,包括Lachnum brevipilosum,Lachnum carfteolu,Lachnum controversum,Lachnum nudipes,Lachnum pseudocorreae和Lachnum virgineum,利用物种描述式表明了种的主要特征,并对其中部分种进行了讨论。  相似文献   
89.
蛋白反式剪接是蛋白翻译后修饰的一种特殊机制,这一反应由断裂型内含肽自我催化完成,不需要酶和其他因子参与。与常规顺式的蛋白剪接不同的是,反式剪接是基于断裂型内含肽由N端和C端这两段多肽的高亲和力,精准地构建成一个具有剪接活性的内含肽蛋白质。反式剪接已被发展成新的生物技术应用于生产环化蛋白、构建蛋白定点与定时表达的载体和转基因植物,以及改造cDNA文库技术等。  相似文献   
90.
INTRODUCTIONThaillll (TNF-related apoptosis inducing ligand)is a recently described member of the TNF family.Like other members of the TNF ligand family) availcould induce apoptosis of neoplastically transformedcells by priVating cell surface death receptors ThailRI and ThaiLR212].Trail has been demonstrated to play an important role in homeostasis of immune system includ.lug eradication of the old lymphocytel3], actiVationinduced T cell deathI41, regulation Of T cen eXPansion by…  相似文献   
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