973 resultados para proton pump inhibitor


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水稻既是我国三大粮食作物之一,又是基因组学研究的模式材料,在生产实践和科学研究中都占有极其重要的地位。基因组学研究取得的巨大成就以前所未有的深度和广度推动了生命科学各个研究领域的飞速发展。水稻基因组的破译是水稻科学研究的重要里程碑,同时也宣告了功能基因组学时代的到来。蛋白质组学是研究细胞内全部蛋白质的动态表达及其相互关系的新兴学科,是功能基因组学研究的重要组成部分和战略制高点。 本论文采用高分辨率的蛋白质双向电泳分离技术和高通量的蛋白质质谱分析技术以及生物信息学等手段,开展水稻灌浆期茎蛋白质组表达模式和水稻幼苗脱黄化过程的比较蛋白质组学研究,探讨茎生长发育规律和水稻应答光信号相关蛋白质及其网络调控机制,是学科前沿与实际应用的有机结合,在科研和生产实践中都具有重要的意义。 首先,分别构建了灌浆期水稻顶端茎段和水稻黄化幼苗的蛋白质组表达谱。并对其中185个目的蛋白点进行了MALDI-TOF/MS分析和数据库检索鉴定。共有149个蛋白质得到了鉴定,蛋白质鉴定的成功率为80.5%。这些被鉴定的蛋白质分属118个基因的表达产物,根据它们功能可以分为13种不同的类别,其中绝大多数为能量产生和代谢以及抗性相关的蛋白质。 在水稻灌浆期顶端茎段表达的蛋白质中,与能量和物质代谢相关的蛋白质例如ATPase、磷酸丙糖异构酶,6-磷酸葡萄糖异构酶等占有很高比例,说明茎段组织中具有很强的代谢活动。与生长发育相关的蛋白质包括beta-tubulins、无机焦磷酸酶(inorganic pyrophosphatase)、液泡质子ATP酶(vacuolar proton-ATPase)以及UDP葡萄糖焦磷酸酶等的大量累积,显示出顶端茎段细胞分裂和生长迅速;同时,贮存多糖和结构多糖也在旺盛合成。G蛋白、GDP释放抑制因子等信号传导蛋白以及苯丙氨酸氨解酶、谷胱苷肽S转移酶(glutathione S-transferase,GST)、抗坏血酸过氧化酶(ascorbate peroxidase,APX)以及超氧化物歧化酶(superoxide dismutase,SOD)等抗性相关蛋白质在该时期丰度表达,表明在灌浆期水稻顶端茎段能够迅速感受并传递外界信号,从而使得其在遭受胁迫时能够立刻启动抗逆防御系统,最大限度地降低不利环境对种子发育的影响。 在黑暗中萌发和生长的水稻黄化幼苗随着光照时间(0~24小时)的延长,能通过双向电泳后检测到的蛋白质逐渐变少,24小时后趋于稳定,相当于正常光照条件下生长的水稻幼苗蛋白质组表达谱。进一步分析表明,在黄化苗中,分解代谢及能量产生相关的蛋白如丙糖磷酸异构酶、琥珀酰辅酶A连接酶、异戊酰辅酶A脱氢酶与ATPase等的表达量比较丰富;另外,还可能启动了脂肪酸的α氧化分解途径,以供黑暗中生长所需的物质和能量。当黄化幼苗光照后,与光合作用及物质合成相关的一些蛋白质表达量增加,而那些分解代谢相关酶类则有所下降。同时,鸟核苷酸结合蛋白β亚基类似蛋白、20S proteasome以及Bowman Birk trypsin inhibitor等信号传递及抗性相关蛋白随着光照时间的延长而减少,说明黑暗胁迫条件下水稻幼苗启动了相关的抗逆途径。叶绿素合成途径中的蛋白酶胆色素原脱氨基酶和金属鳌合酶在脱黄化过程中表达量有所下降,可能是因为叶绿素合成产物具有反馈抑制作用。 本研究首次利用蛋白质组学方法来解析水稻灌浆期茎蛋白质组表达模式和水稻黄化幼苗响应光因子的蛋白质组变化情况,鉴定了一些有价值的蛋白质,并得到了它们的表达特点和相关数据,为更好地理解水稻顶端茎秆的生长特点和功效、水稻应答黑暗胁迫和光形态建成以及光合作用机理等提供了分子证据。

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A semiconductor optical amplifier monolithically integrated with a distributed feedback pump laser is used for non-degenerate four wave mixing applications. Experimental results are presented which illustrate the use of this compact device for both wavelength conversion and dispersion compensation applications at high data rates.

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A novel trypsin inhibitor was identified and purified from skin secretions of Chinese red-belly toad Bombina maxima. The partial N-terminal 29 amino acid residues of the peptide, named BMTI, were determined by automated Edman degradation. This allowed the cloning of a full-length cDNA encoding BMTI from a cDNA library prepared from the toad skin. The deduced complete amino acid sequence of BMTI indicates that mature BMTI is composed of 60 amino acids. A FASTA search in the databanks revealed that BMTI exhibits 81.7% sequence identity with BSTI, a trypsin/thrombin inhibitor from European toad Bombina bombina skin secretions. Sequence differences between BMTI and BSTI were due to 11 substitutions at positions 2, 9, 25, 27, 36-37, 39, 41-42, 50 and 56. BMTI potently inhibited trypsin with a K-i value of 0.06 muM, similar to that of BSTI. However, unlike BSTI, which also inhibited thrombin with a K-i value of 1 muM, no inhibitory effect of BMTI on thrombin was observed under the assay conditions. (C) 2002 Elsevier Science Inc. All rights reserved.

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Amphibian skin secretions contain many bioactive compounds. In the present work, an irreversible serine protease inhibitor, termed baserpin, was purified for the first time from the skin secretions of toad Bufo andrewsi by Successive ion-exchange and gelfiltration chromatography. Baserpin is a single chain glycoprotein, with an apparent molecular weight of about 60 kDa in SDS-PAGE. Baserpin is an irreversible inhibitor and effectively inhibits the catalytic activity of trypsin, chymotrypsin and elastase. SDS-stable baserpin-trypsin complex could be seen in SDS-PAGE indicates that it possibly belongs to the serpin superfamily. According to the association rates determined, baserpin is a potent inhibitor of bovine trypsin (4.6 X 10(6) M-1 S-1), bovine chymotrypsin (8.9 X 10(6) M-1 s(-1)) and porcine elastase (6.8 X 10(6) M-1 s(-1)), whereas it shows no inhibitory effect on thrombin. The N-terminal sequence of baserpin is HTQYPDILIAKPXDK, which shows no similarity with other known serine protease inhibitors. (c) 2005 Elsevier Ltd. All rights reserved.

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A novel potent trypsin inhibitor was purified and characterized from frog Bombina maxima skin. A full-length cDNA encoding the protein was obtained from a cDNA library constructed from the skin. Sequence analysis established that the protein actually comprises three conserved albumin domains. B. maxima serum albumin was subsequently purified, and its coding cDNA was further obtained by PCR-based cloning from the frog liver. Only two amino acid variations were found in the albumin sequences from the skin and the serum. However, the skin protein is distinct from the serum protein by binding of a haem b (0.95 mol/mol protein). Different from bovine serum albumin, B. maxima albumin potently inhibited trypsin. It bound tightly with trypsin in a 1: 1 molar ratio. The equilibrium dissociation constants (K-D) obtained for the skin and the serum proteins were 1.92 x 10(-9) M and 1.55 x 10(-9) M, respectively. B. maxima albumin formed a noncovalent complex with trypsin through an exposed loop formed by a disulfide bond (Cys(53)-Cys(62)), which comprises the scissile bond Arg(58)(P-1)-His(59)(P-1'). No inhibitory effects on thrombin, chymotrypsin, elastase, and subtilisin were observed under the assay conditions. Immunohistochemical study showed that B. maxima albumin is widely distributed around the membranes of epithelial layer cells and within the stratum spongiosum of dermis in the skin, suggesting that it plays important roles in skin physiological functions, such as water economy, metabolite exchange, and osmoregulation.

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A novel peptide inhibitor (OGTI) of serine protease with a molecular weight of 1949.8, was purified from the skin secretion of the frog, Odorrana grahami. Of the tested serine proteases, OGTI only inhibited the hydrolysis activity of trypsin on synthetic chromogenic substrate. This precursor deduced from the cDNA sequence is composed of 70 amino acid residues. The mature OGTI contains 17 amino acid residues including a six-residue loop disulfided by two half-cysteines (AVNIPFKVHFRCKAAFC). In addition to its unique six-residue loop, the overall structure and precursor of OGTI are different from those of other serine protease inhibitors. It is also one of the smallest serine protease inhibitors ever found. (C) 2008 Elsevier Masson SAS. All rights reserved.

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High temperature superconductors, such as melt-processed YBCO bulks, have great advantages on trapping strong magnetic fields in liquid nitrogen. To enable them to function well, there are some traditional ways of magnetizing them, in which the YBCO bulks are magnetized instantly under a very strong source of magnetic field. These ways would consume great amounts of power to make the superconductors trap as much field as possible. Thermally Actuated Magnetization (TAM) Flux pump has been proved a perfect substitution for these expensive methods by using a relatively small magnet as the source. In this way, the field is developed gradually over many pulses. Unlike conventional flux pumping ways, the TAM does not drive the superconductor normal during the process of magnetization. In former experiments for the flux pump, some fundamental tests were done. In this paper, the experiment system is advanced to a new level with better temperature control to the thermal waves moving in the Gadolinium and with less air gap for the flux lines sweeping through the superconductor. This experiment system F leads to a stronger accumulation of the magnetic field trapped in the YBCO bulk. We also tried different ways of sending the thermal waves and found out that the pumping effect is closely related to the power of the heaters and the on and off time. © 2010 IEEE.

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By Sephadex G-50 gel filtration, Resource Q anionic exchange and C4 reversed phase liquid high performance liquid chromatography, a proteinase inhibitor protein (Ranaserpin) was identified and purified from the eggs of the odour frog, Rana grahami. The protein displayed a single band adjacent to the molecular weight marker of 14.4 kDa analyzed by SDS-PAGE. The inhibitor protein homogeneity and its molecular weight were confirmed again by MALDI-TOF mass spectrometry analysis. The MALDI-TOF mass spectrum analysis gave this inhibitor protein an m/z of 14422.26 that was matched well with the result from SDS-PAGE. This protein is a serine proteinase inhibitor targeting multiple proteinases including trypsin, elastase, and subtilisin. Ranaserpin inhibited the proteolytic activities of trypsin, elastase, and subtilisin. It has an inhibitory constant (K-i) of 6.2 x 10(-8) M, 2.7 x 10(-7) M and 2.2 x 10(-8) M for trypsin, elastase, and subtilisin, respectively. This serine proteinase inhibitor exhibited bacteriostatic effect on Gram-positive bacteria Bacillus subtilis (ATCC 6633). It was suggested that ranaserpin might act as a defensive role in resistance to invasion of pests or pathogens. This is the first report of serine proteinase inhibitor and its direct defensive role from amphibian eggs. (C) 2007 Elsevier Inc. All rights reserved.

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Snake venom Kunitz/BPTI members are good tools for understanding of structure-functional relationship between serine proteases and their inhibitors. A novel dual Kunitz/BPTI serine proteinase inhibitor named OH-TCI (trypsin- and chymotrypsin-dual inhibito

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The Ag5 proteins are the most abundant and immunogenic proteins in the venom secretory ducts of stinging insects. An antigen 5-like protein (named tabRTS) composed of 221 amino acid residues was purified and characterized from the salivary glands of the horsefly, Tabanus yao (Diptera, Tabanidae). Its cDNA was cloned from the cDNA library of the horsefly's salivary gland. TabRTS containing the SCP domain (Sc7 family of extracellular protein domain) was found in insect antigen 5 proteins. More interestingly, there is an Arg-Thr-Ser (RTS) disintegrin motif at the C-terminus of tabRTS. The RTS motif is positioned in a loop bracketed by cysteine residues as those found in RTS-disintegrins of Crotalidae and Viperidae snake venoms, which act as angiogenesis inhibitors. Endothelial Cell Tube formation assay in vitro and chicken chorioallantoic membrane (CAM) angiogenesis assay in vivo were performed as to investigate the effect of tabRTS on angiogenesis. It was found that tabRTS could significantly inhibit angiogenesis in vitro and in vivo. Anti-alpha(1)beta(1) monoclonal antibody could dose-dependently inhibit the anti-angiogenic activity of tabRTS. This result indicated that tabRTS possibly targets the alpha(1)beta(1) integrin to exert the anti-angiogenic activity as snake venom RTS-/KTS-disintegrins do. The current work revealed the first angiogenesis inhibitor protein containing RTS motif from invertebrates, a possible novel type of RTS-disintegrin. (C) 2009 Elsevier Ltd. All rights reserved.

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Trichosanthin (TCS) is a type I ribosome-inactivating protein possessing multiple biological and pharmacological activities. One of its major actions is inhibition of human immunodeficiency virus (HIV) replication. The mechanism is still not clear. It is

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Integration of viral-DNA into host chromosome mediated by the viral protein HIV-1 integrase (IN) is an essential step in the HIV-1 life cycle. In this process, Lens epithelium-derived growth factor (LEDGF/p75) is discovered to function as a cellular co-fa

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Enfuvirtide (ENF) is currently the only FDA approved HIV fusion inhibitor in clinical use. Searching for more drugs in this category with higher efficacy and lower toxicity seems to be a logical next step. In line with this objective, a synthetic peptide