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1.
Izuru Yamamoto Hideo Kamimura Ryo Yamamoto Seiroku Sakai Masayoshi Goda 《Bioscience, biotechnology, and biochemistry》2013,77(10):709-716
Toxicities of some nicotinoids as an insecticide were determined. 5′-methylnornicotine, a new synthetic isomer of nicotine, shows similar toxicity to nicotine. The essential moiety in nicotinoids molecule responsible for high toxicity may be 3-pyridylmethylamine group, the amino nitrogen of which must have high basicity (pKa′: 7.4~9.0). All nicotinoids of high toxicity are estimated to be largely as monocation at physiological pH of 7. 相似文献
2.
Blobe GC Schiemann WP Pepin MC Beauchemin M Moustakas A Lodish HF O'Connor-McCourt MD 《The Journal of biological chemistry》2001,276(27):24627-24637
Transforming growth factor beta (TGF-beta) signals through three high affinity cell surface receptors, TGF-beta type I, type II, and type III receptors. The type III receptor, also known as betaglycan, binds to the type II receptor and is thought to act solely by "presenting" the TGF-beta ligand to the type II receptor. The short cytoplasmic domain of the type III receptor is thought to have no role in TGF-beta signaling because deletion of this domain has no effect on association with the type II receptor, or with the presentation role of the type III receptor. Here we demonstrate that the cytoplasmic domains of the type III and type II receptors interact specifically in a manner dependent on the kinase activity of the type II receptor and the ability of the type II receptor to autophosphorylate. This interaction results in the phosphorylation of the cytoplasmic domain of the type III receptor by the type II receptor. The type III receptor with the cytoplasmic domain deleted is able to bind TGF-beta, to bind the type II receptor, and to enhance TGF-beta binding to the type II receptor but is unable to enhance TGF-beta2 signaling, determining that the cytoplasmic domain is essential for some functions of the type III receptor. The type III receptor functions by selectively binding the autophosphorylated type II receptor via its cytoplasmic domain, thus promoting the preferential formation of a complex between the autophosphorylated type II receptor and the type I receptor and then dissociating from this active signaling complex. These studies, for the first time, elucidate important functional roles of the cytoplasmic domain of the type III receptor and demonstrate that these roles are essential for regulating TGF-beta signaling. 相似文献
3.
Koichi Matsuzaki Mikio Kan Wallace L. McKeehan 《In vitro cellular & developmental biology. Animal》1996,32(6):345-360
Summary Two transmembrane serine-threonine kinases (type I and II receptors), a membrane-anchored proteoglycan (type III), and a homodimeric
ligand participate in the transforming growth factor beta type on (TGFβ1) signal transduction complex. The expression of recombinant
receptors in insect cells co-infected with up to three recombinant baculoviruses was employed to study interactions among
the ectodomains of the three types of receptors and the TGFβ1 ligand in absence of uncontrollable extrinsic factors in mammalian
cells. Multi-subunit complexes were assembled in intact cells and purified on glutathione-conjugated beads for analysis by
tagging one of the subunits with glutathione S-transferase (GST). Intrinsic ligand-independent interactions were observed
among receptor subunits as follows: type III–III type I–I, type III-I, and type II-I. The homeotypic complex of type II–II
receptors and the heterotypic type III-II interaction was ligand dependent. The type I, but not the type III, subunit displaced
about 50% of the type II component in either ligand-dependent homomeric type II-type II complexes or heteromeric type III-type
II complexes to form type II-I or type III-II-I oligomers, respectively. The type II subunit displaced type I subunits in
oligomers of the type I subunit. Specificity of type I receptors may result from differential affinity for the type II receptor
rather than specificity for ligand. A monomeric subunit of the TGFβ1 ligand bound concurrently to type III and type II or
type III and type I receptors, but failed to concurrently bind to the type II and type I subunits. The binding of TGFβ1 to
the type I kinase subunit appears to require an intact disulfide-linked ligand dimer in the absence of a type III subunit.
The combined results suggest a pentameric TGFβ signal transduction complex in which one unit each of the type III, type II,
and type I components is assembled around the two subunits of the dimeric TGFβ1 ligand. An immobilized GST-tagged subunit
of the receptor complex was utilized to assemble multi-subunit complexesin vitro and to study the phosphorylation events among subunits in the absence of extrinsic cell-derived kinases. The results revealed
that (a) a low level of ligand-independent autophosphorylation occurs in the type I kinase; (b) a high level of autophosphorylation
occurs in the type II kinase; (c) both the type III and type I subunits aretrans-phosphorylated by the type II subunit; and (d) the presence of both type I and II kinases complexed with the type III subunit
and dimeric TGFβ1 ligand in a pentameric complex causes maximum phosphorylation of all three receptor subunits. 相似文献
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利用简并PCR技术从野生花生种(Arachis ipaensis Krapov. et W. C. Greg.)的基因组中扩增分离Ty1-copia类(1类)和Ty3-gypsy类(2类)反转录转座子RT基因,并对其序列特征、多样性、系统进化关系及转录活性进行分析。结果显示:对于1和2类RT基因,目的条带分别约为260和430 bp;分离获得了23和32条序列,长度范围分别为262~266、395~435 bp;AT所占比例分别为61.60%~69.17%和55.79%~61.34%;核苷酸序列间相似性分别为52.5%~98.9%和45.0%~98.8%,氨基酸序列间相似性分别为39.8%~100%和9.0%~97.2%。其中2类基因的异质性高于1类;1类和2类基因分别有3条和15条发生了无义突变,2类的无义突变发生率远高于1类。1类基因的保守基序保守性较高,2类的保守基序呈一定程度的变异。代表序列的蛋白质三级结构基本类似。聚类分析结果显示,1类和2类基因可被分为5个和6个家族。1类和2类基因都有部分序列与其他物种的RT基因序列亲缘关系较近,表明它们之间可能存在两类反转录转座子的横向传... 相似文献
6.
The contents of type I, type III and type V collagen and the collagen type specific distributions in liver under normal and cirrhotic conditions were examined. In CCl4 injected rat, the increasing amount of type V collagen was a specific event during the progression of cirrhosis. In normal liver, immunohistochemical observation showed that type V collagen was localized on the fine fibrils, while type I was localized on the thick fibril. Type V collagen was partially colocalized with type IV collagen. In the cirrhotic liver, type V collagen was localized on the margin of the thick fibrous septa along with type IV collagen. Type I collagen existed in the core region of fibrous septa where the stellate cells were prominent. To elucidate the mechanism of the type specific deposition of collagen in the liver, we constructed a coculture system using both stellate cells and hepatocytes. In this system, type V collagen was mainly deposited on hepatocyte colonies not on stellate cells, while type I collagen fibrils were localized on stellate cells. The spatial positioning of type I and type V collagens in vitro was similar to that in the liver. In the cell adhesion assay, the adhesion of stellate cells to type V collagen was poorer than that of the hepatocytes. The collagen type-specific affinity of the stellate cells and hepatocytes may explain the specific localization of type V collagen in the liver and coculture system. These results suggested that the functions of type V collagen are not only to connect type IV collagen with type I collagen fibril, but also to protect the parenchyma from excess type I collagen deposition produced by stellate cells under pathological conditions. 相似文献
7.
苔纲(Hepaticae)植物雌性生殖苞的形态学研究 总被引:1,自引:0,他引:1
以比较形态解剖学方法,对苔纲 (Hepaticae) 植物雌性生殖苞的结构及其不同成分起源进行了研究。首次把苔纲雌性生殖苞(Perichaetium)分为蒴帽型(Calyptra type)、蒴萼型(Perianth type)、鞘萼型(Coelocaule-perianth type)、茎鞘型(Coelocaule type)、蒴囊型(Perigynium type)、总苞型(Involucre type)和托生总苞型(Carpocephalum involucre type)等雌苞类型,并指明其中蒴帽型雌苞(Perichaetium of calyptra type of Hepaticae)最简单,为演化原始类群,托生总苞型雌苞(Perichaetium of carpocephalum involucre type of Hepaticae)演化最高级。还首次提出了雌苞演化示意图和“苞图式”表示苔类的雌苞结构。 相似文献
8.
目的:探讨不同乳腺分型(Ⅰ型(脂肪型)、Ⅱ型(致密型)、Ⅲ型(中间型)、Ⅳ型(导管型))、不同乳腺厚度与全数字化乳腺X射线摄影曝光条件(kV、mms)、平均腺体剂量(mGy)之间的关系。方法:回顾性分析2009年9月-2010年6月间采用德国Siemens公司MAMMOMAT Novation DR全数字化乳腺摄影系统、自动曝光控制模式下摄影所获得的2000例头尾位和内外侧斜位乳腺片,分析7840幅Ⅰ级乳腺照片中不同乳腺分型、不同乳腺厚度的曝光条件、平均腺体剂量,以研究乳腺分型及乳腺厚度与全数字化乳腺X线摄影曝光条件及平均腺体剂量的关系。结果:当乳腺厚度相同时,Ⅱ型(致密型)乳腺的曝光条件及平均腺体剂量最大,Ⅳ型(导管型)次之,Ⅲ型(中间型)再次之,Ⅰ型(脂肪型)乳腺的曝光条件及平均腺体剂量最小。无论何种乳腺分型,随着乳腺厚度的增加,全数字化乳腺X射线摄影曝光条件及平均腺体剂量随之增加。结论:乳腺分型及乳腺厚度与全数字化乳腺X射线摄影曝光条件及平均腺体剂量关系密切,乳腺腺体组织越致密、厚度越厚,其曝光条件及平均腺体剂量就越大。 相似文献
9.
大孔吸附树脂分离纯化人参二醇类和三醇类皂甙 总被引:9,自引:2,他引:9
本实验研究大孔吸附树脂从人参根提取物中富集、分离人参二醇类和人参三醇类皂甙的工艺条件及参数。用不同浓度的乙醇洗脱,使人参二醇类和三醇类皂甙实现富集分离,人参二醇类皂甙富集在80%乙醇洗脱液部分,人参三醇类皂甙富集在40%洗脱液部分。得到含量大于25%的人参三醇类皂甙,含量大于50%的人参二醇类皂甙,总皂甙洗脱率在91%以上。此法能够较好地分离、纯化人参二醇类和三醇类皂甙。 相似文献
10.
Cross-regulation between type I and type II NKT cells in regulating tumor immunity: a new immunoregulatory axis 总被引:2,自引:0,他引:2
Ambrosino E Terabe M Halder RC Peng J Takaku S Miyake S Yamamura T Kumar V Berzofsky JA 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(8):5126-5136
Negative immunoregulation is a major barrier to successful cancer immunotherapy. The NKT cell is known to be one such regulator. In this study we explored the roles of and interaction between the classical type I NKT cell and the poorly understood type II NKT cell in the regulation of tumor immunity. Selective stimulation of type II NKT cells suppressed immunosurveillance, whereas stimulation of type I NKT cells protected against tumor growth even when responses were relatively skewed toward Th2 cytokines. When both were stimulated simultaneously, type II NKT cells appeared to suppress the activation in vitro and protective effect in vivo of type I NKT cells. In the absence of type I, suppression by type II NKT cells increased, suggesting that type I cells reduce the suppressive effect of type II NKT cells. Thus, in tumor immunity type I and type II NKT cells have opposite and counteractive roles and define a new immunoregulatory axis. Alteration of the balance between the protective type I and the suppressive type II NKT cell may be exploited for therapeutic intervention in cancer. 相似文献
11.
The secretory granules of rat bronchiolar Clara cells were classified into different types by their ultrastructural appearances followed by immunocytochemistry using anti-rat 10 kDa Clara cell-specific protein (10 kDa CCSP) antibody. One predominant type was the oval to round granule (type A granule), of which the matrix was composed of a map-like mixture of electron-dense and less electron-dense material. Another predominant type was the rod-shaped granule (type B granule). The content of type B granules varied from a finely fibrillar (type B1 granule) to an electron-dense, rod-like (type B3 granule) structure. Various intermediate types (type B2 granule) between type B1 and B3 granules were also found. Small cytoplasmic vesicles were found occasionally in close proximity to type B2 or B3 granule. Another type of granule (type C granule) was large, up to 8 microns in diameter, and contained a moderately electron-dense amorphous matrix. Both type A and C granules stained at a similar density with the antibody. The nascent form of type A granules, which was found in the vicinity to the trans face of the Golgi apparatus, was also labeled. On the other hand, the labeling density of type B granules varied: type B1 granules were almost devoid of immunolabeling, whereas type B3 granules were intensely labeled. Type B2 granules stained with the antibody; however, the labeling density was less than that of type B3 granules. The small cytoplasmic vesicles of type B2 granules were labeled.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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13.
Duddy WJ Nissink JW Allen FH Milner-White EJ 《Protein science : a publication of the Protein Society》2004,13(11):3051-3055
Hydrogen-bonded beta-turns in proteins occur in four categories: type I (the most common), type II, type II', and type I'. Asx-turns resemble beta-turns, in that both have an NH. . .OC hydrogen bond forming a ring of 10 atoms. Serine and threonine side chains also commonly form hydrogen-bonded turns, here called ST-turns. Asx-turns and ST-turns can be categorized into four classes, based on side chain rotamers and the conformation of the central turn residue, which are geometrically equivalent to the four types of beta-turns. We propose asx- and ST-turns be named using the type I, II, I', and II' beta-turn nomenclature. Using this, the frequency of occurrence of both asx- and ST-turns is: type II' > type I > type II > type I', whereas for beta-turns it is type I > type II > type I' > type II'. Almost all type II asx-turns occur as a recently described three residue feature named an asx-nest. 相似文献
14.
Tyrosinase gene mutations associated with type IB ("yellow") oculocutaneous albinism 总被引:8,自引:4,他引:4
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L B Giebel R K Tripathi K M Strunk J M Hanifin C E Jackson R A King R A Spritz 《American journal of human genetics》1991,48(6):1159-1167
We have identified three different tyrosinase gene mutant alleles in four unrelated patients with type IB ("yellow") oculocutaneous albinism (OCA) and thus have demonstrated that type IB OCA is allelic to type IA (tyrosinase negative) OCA. In an inbred Amish kindred, type IB OCA results from homozygosity for a Pro----Leu substitution at codon 406. In the second family, type IB OCA results from compound heterozygosity for a type IA OCA allele (codon 81 Pro----Leu) and a novel type IB allele (codon 275 Val----Phe). In the third patient, type IB OCA results from compound heterozygosity for the same type IB allele (codon 275 Val----Phe) and a novel type IB OCA allele. In a fourth patient, type IB OCA results from compound heterozygosity for the codon 81 type IA OCA allele and a type IB allele that contains no identifiable abnormalities; dysfunction of this type IB allele apparently results from a mutation either well within one of the large introns or at some distance from the tyrosinase gene. In vitro expression of the Amish type IB allele in nonpigmented HeLa cells demonstrates that the Pro----Leu substitution at codon 406 greatly reduces but does not abolish tyrosinase enzymatic activity, a finding consistent with the clinical phenotype. 相似文献
15.
We have immunohistochemically examined the distribution of the H antigens of type 1, type 2 and type 3/4 chains of the ABO(H) histo-blood group system in human normal colon and in colon cancer using three monoclonal antibodies specific for each of the H type 1/2, H type 2, and the H type 3/4 chain. We unexpectedly found that mucosa of the normal colon from secretors but not that from nonsecretors expressed only H type 1 and did not express H type 2 or H type 3/4. The H type 1 was expressed in goblet cells. Positive goblet cells expressing H type 1 were decreased in number progressively from the proximal colon to the rectum. In tumors, 4 (57%) of 7 cancer tissues of the proximal colon from secretors expressed no H type 1, whereas all 8 cancer tissues of the distal colon from secretors expressed H type 1. The aberrant expressions of H type 2 and H type 3/4 (47 and 67%, respectively) were found in cancer tissues from both the proximal and the distal colon. Tumors from nonsecretors did not express any H antigens. Our results suggested that the expression of H type 1 in the normal colon and the aberrant expressions of H type 2 and H type 3/4 in colon cancer tissues were regulated by FUT2-encoded Se type (1,2)fucosyltransferase. However, UEA-I-positive substance(s) rather than H type 2 were uniquely expressed throughout the normal colon and in colon cancers from both secretors and nonsecretors. 相似文献
16.
目的:探讨64排螺旋CT对粗隆间骨折Evans分型的影响,为临床使用提供参考依据。方法:2015年3月至2017年3月,三甲医院高年资创伤骨科主任医师2名,医师1、医师2分别按照术前X线、术前64排螺旋CT平扫和三位重建结果对128例新鲜闭合单侧粗隆间骨折患者进行Evans分型,分别记为X线分型、CT分型。本院术者依据围术期X线、CT及术中所见骨折情况进行Evans分型(逆粗隆间骨折定义为Ⅴ型)作为最终分型。记录分型结果,计算并对比准确率、误诊率。结果:(1)剔除5例,90.09%(123/128)的患者完成研究。(2)分型结果:X线分型中,3例(最终分型Ⅲ型2例,Ⅳ型1例)无法定型;Ⅰ型正确1例,改为Ⅱ型1例;Ⅱ型正确18例,改为Ⅰ型2例,改为Ⅲ型3例,Ⅳ型2例;Ⅲ型正确45例,改为Ⅱ型7例,改为Ⅳ型1例;Ⅳ型正确19例,改为Ⅱ型3例,改为Ⅲ型15例。CT分型中,Ⅰ型正确3例,Ⅱ型正确29例,Ⅲ型正确64例,改为Ⅳ型1例,Ⅳ型正确22例,Ⅴ型正确3例。(3)CT分型的总准确率、总误诊率优于X线分型(99.19%vs67.48%、0.81%vs30.08%,P0.05)。(4)Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型骨折进行CT分型,准确率高于X线分型(P0.05),误诊率低于X线分型(P0.05);Ⅴ型骨折,两种分型准确率、误诊率相等。结论:64排螺旋CT平扫及三维重建是粗隆间骨折Evans分型较为可靠的辅助检查,可考虑推广运用。 相似文献
17.
Kato T Kawai S Nakano K Inaba H Kuboniwa M Nakagawa I Tsuda K Omori H Ooshima T Yoshimori T Amano A 《Cellular microbiology》2007,9(3):753-765
Porphyromonas gingivalis is a periodontal pathogen whose fimbriae are classified into six genotypes based on the diversity of the fimA genes encoding each fimbria subunit. It was suggested that P. gingivalis strains with type II fimbriae were more virulent than type I strains. For the present study, we generated the mutants in which fimA was substituted with different genotypes to study virulence of type II fimbriae. Using plasmid vectors, fimA of ATCC33277 (type I strain) was substituted with type II fimA, and that of OMZ314 (type II strain) with type I fimA. The substitution of type I fimA with type II enhanced bacterial adhesion/invasion to epithelial cells, whereas substitution with type I fimA resulted in diminished efficiency. Following bacterial invasion, type II clones swiftly degraded cellular paxillin and focal adhesion kinase, and inhibited cellular migration, whereas type I clones and DeltafimA mutants did not. BIAcore analysis demonstrated that type II fimbriae possess greater adhesive abilities for their receptor alpha5beta1-integrin than those of type I. In a mouse abscess model, the type II clones significantly induced serum IL-1beta and IL-6, as well as other infectious symptoms. These results suggest that type II fimbriae are a critical determinant of P. gingivalis virulence. 相似文献
18.
Rat liver xanthine dehydrogenase, type D, has been isolated directly from crude extracts as an antibody complex and its properties compared with those of two oxidase forms of the enzyme, heat-treated type O and trypsin-treated type O, also isolated as antibody complexes. The type D antibody complex displays electron acceptor specificities and electron paramagnetic resonance properties characteristic of an NAD+-dependent dehydrogenase whereas the trypsin-treated type O complex behaves as an O2-utilizing oxidase. The heat-treated type O complex displays intermediate behavior. After electrophoresis in dodecyl sulfate-urea-acrylamide gels, type D and heated type O enzymes show single polypeptide bands, each of approximately 150,000 molecular weight. The trypsinized type O also shows one major band but with an approximate molecular weight of 130,000. Purified type D enzyme, when proteolytically treated, is converted to an oxidase with increased mobility on polyacrylamide gels. The 150,000 molecular weight subunit is cleaved into smaller subunits during proteolysis. Treatment with 5,5′-dithiobis-(2-nitrobenzoic acid) converts the type D enzyme, whether isolated as the purified enzyme or as the immune precipitate, to type O enzyme in a time-dependent manner. Titration of type D and the two type O antibody complexes with 5,5′-dithiobis-(2-nitrobenzoic acid) reveals that type D and heated type O each has approximately 28 reactive sulfhydryls, whereas the trypsinized type O has only 8 such groups. Many of the free sulfhydryls are vicinal and form disulfide bonds during the conversion to an oxidase by this reagent. Unproteolyzed preparations of type O rat liver enzyme and milk xanthine oxidase are converted to type D enzymes by treatment with dithiothreitol. The converted enzymes display electron acceptor specificities and epr properties characteristic of an NAD+-dependent dehydrogenase molecule. 相似文献
19.
K Ishii T Kita M Yokode N Kume Y Nagano H Otani T Yamamura S Murayama Y Morimoto Y Teranishi 《Journal of lipid research》1989,30(1):1-7
We investigated the properties of very low density lipoprotein (VLDL) from two types of Watanabe heritable hyperlipidemic (WHHL) rabbits: one with a high incidence of coronary atherosclerosis (type 1), and the other with a low incidence (type 2). When incubated with mouse peritoneal macrophages, VLDL from type 1 WHHL rabbit (type 1-VLDL) stimulated cholesteryl ester synthesis 10.5-fold more than VLDL from the type 2 WHHL rabbit (type 2-VLDL) did. Moreover, a similar difference was seen in the stimulation of cholesteryl ester synthesis in peritoneal macrophages isolated from the WHHL rabbits. The mass ratios of cholesterol to protein in type 1- and type 2-VLDL were 5.69 and 2.05, respectively. Agarose gel electrophoresis of type 1-VLDL showed beta mobility, and that of type 2-VLDL showed pre-beta mobility. No difference was seen between the sizes of VLDL particles of the two types. The amount of apolipoprotein E in type 1-VLDL was greater than that in type 2-VLDL. In conclusion, the difference between type 1 and type 2 WHHL rabbits is at least partly due to the presence in type 1 animals of VLDL particles rich in cholesteryl esters and apolipoprotein E, particles which are very similar to beta-VLDL in conformation. 相似文献
20.
为了解二毛期时滩羊串子花型裘皮与其它类型裘皮中蛋白质的差异,本试验采用iTRAQ技术及LC-MS/MS蛋白质组学研究方法,对串子花型、软大花型、绿豆丝型及其它不规则型花穗裘皮蛋白质进行鉴定和筛选,并运用Proteome Discoverer l.4软件进行定量分析,结合数据库搜索,鉴定出具有显著表达差异的蛋白,同时应用生物学技术对其进行GO和Pathway分析。结果显示4类花穗型裘皮共检测出2 886个蛋白,其中有135个、142个、113个差异蛋白分别存在于软大花型与串子花型、绿豆丝型与串子花型、其它不规则型与串子花型3个对比组中。对有表达差异的蛋白进行分析,发现膜联蛋白与血管内皮生长因子可能与软大花型毛股形成相关,KAP3和KAP6可能与滩羊串子花型毛股结构相关。研究发现滩羊不同二毛裘皮蛋白水平上的差异,可为选育优良的滩羊串子花型二毛裘皮提供理论基础。 相似文献