生物化工專(zhuān)業(yè)翻譯.doc

生物化工專(zhuān)業(yè)翻譯1. AbstractAmyloid disorders cause debilitating illnesses through the formation of toxic protein aggregates. The mechanisms of amyloid toxicity and the nature of species responsible for mediating cellular dysfunction remain unclear. Here, using 2-microglobulin (2m) as a model system, we show that the disruption of membranes by amyloid fibrils is caused by the molecular shedding of membrane-active oligomers in a process that is dependent on pH. Using thioflavin T (ThT) fluorescence, NMR, EM and fluorescence correlation spectroscopy (FCS), we show that fibril disassembly at pH 6.4 results in the formation of nonnative spherical oligomers that disrupt synthetic membranes. By contrast, fibril dissociation at pH 7.4 results in the formation of nontoxic, native monomers. Chemical cross-linking or interaction with hsp70 increases the kinetic stability of fibrils and decreases their capacity to cause membrane disruption and cellular dysfunction. The results demonstrate how pH can modulate the deleterious effects of preformed amyloid aggregates and suggest why endocytic trafficking through acidic compartments may be a key factor in amyloid disease.抽象淀粉樣蛋白疾病引起通過(guò)毒性蛋白聚集體的形成衰弱的疾病。淀粉樣蛋白的毒性的機(jī)制，負(fù)責(zé)調(diào)解細(xì)胞功能障礙品種的性質(zhì)仍然不清楚。在這里，用2微球蛋白（2M），其為模型系統(tǒng)，我們表明，膜的由淀粉樣蛋白原纖維的破壞是通過(guò)膜 - 活性低聚物的分子中脫落的處理是依賴(lài)于pH值而引起的。使用硫磺素T（ThT的）熒光，NMR EM和熒光相關(guān)光譜（FCS），我們表明，原纖維的拆卸，在pH 6.4的結(jié)果中的非天然寡聚球形擾亂合成膜的形成。相比之下，原纖維解離，在pH 7.4的結(jié)果在無(wú)毒，天然單體的形成?；瘜W(xué)交聯(lián)或相互作用與HSP70增加纖維的動(dòng)力學(xué)穩(wěn)定性，并降低它們的容量以使膜破壞和細(xì)胞功能障礙。結(jié)果表明如何pH值可以調(diào)節(jié)預(yù)形成的淀粉樣蛋白聚集體的有害作用，并說(shuō)明為什么通過(guò)酸性隔室的內(nèi)吞販賣(mài)可以是在淀粉樣蛋白病的關(guān)鍵因素。2. AbstractDuring the last decade, several pieces of convincing evidence were published indicating that aging of living organisms is programmed, being a particular case of programmed death of organism (phenoptosis). Among them, the following observations can be mentioned 1. Species were described that show negligible aging. In mammals, the naked mole rat is the most impressive example. This is a rodent of mouse size living at least 10-fold longer than a mouse and having fecundity higher than a mouse and no age-related diseases 2. In some species with high aging rate, genes responsible for active organization of aging by poisoning of the organism with endogenous metabolites have been identified 3. In women, standard deviations divided by the mean are the same for age of menarche (an event controlled by the ontogenetic program) and for age of menopause (an aging-related event) 4. Inhibitors of programmed cell death (apoptosis and necrosis) retard and in certain cases even reverse the development of age-dependent pathologies 5. In aging species, the rate of aging is regulated by the individual which responds by changes in this rate to changes in the environmental conditions. In this review, we consider point 5 in detail. Data are summarized suggesting that inhibition of aging rate by moderate food restriction can be explained assuming that such restriction is perceived by the organism as a signal of future starvation. In response to this dramatic signal, the organism switches off such an optional program as aging, mobilizing in such a way additional reserves for survival. A similar explanation is postulated for geroprotective effects of heavy muscle work, a lowering or a rise in the external temperature, small amounts of metabolic poisons (hormesis), low doses of radiation, and other deleterious events. On the contrary, sometimes certain positive signals can prolong life by inhibiting the aging program in individuals who are useful for the community (e.g., geroprotective psychological factors). Similarly, dangerous individuals can be eliminated by programmed death due to operation of progeric psychological factors. The interplay of all these signals results in the final decision of the organism concerning its aging - to accelerate or to decelerate this process. Thus, paradoxically, such an originally counterproductive program as aging appears to be useful for the individual since this program can be switched off by the individual for a certain period of time, an action that thereby increases its resources in crucial periods of life.抽象在過(guò)去的十年，幾件有說(shuō)服力的證據(jù)發(fā)表表明生物體的衰老編程，是對(duì)生物體（機(jī)體衰亡）程序性死亡的具體情況。其中，以下的觀察，可以提及1。物種進(jìn)行了描述，顯示微不足道的老化。在哺乳動(dòng)物中，裸鼴鼠是最令人印象深刻的例子。這是鼠標(biāo)大小生活嚙齒類(lèi)比鼠標(biāo)至少10倍長(zhǎng)，并具有繁殖力比鼠標(biāo)更高并且沒(méi)有年齡有關(guān)的疾病2。在一些物種具有高的老化速率，負(fù)責(zé)老化通過(guò)與內(nèi)源性代謝物的有機(jī)體中毒活性組織的基因已被確定3。在女性中，標(biāo)準(zhǔn)偏差除以平均值是相同的初潮（由個(gè)體發(fā)育程序控制的事件）的年齡和絕經(jīng)（老化有關(guān)的事件）的年齡4。程序性細(xì)胞死亡（凋亡，壞死）和延遲在某些情況下的抑制劑甚至逆轉(zhuǎn)的年齡依賴(lài)性病狀5的發(fā)展。在老化物種，老化的速率由該響應(yīng)由變化的環(huán)境條件的變化，這個(gè)比率的個(gè)別調(diào)節(jié)。在這次審查中，我們考慮了詳細(xì)點(diǎn)5。數(shù)據(jù)概括提示抑制老化速率由中度食物限制可以假定這種限制是由生物體視為未來(lái)饑餓的信號(hào)進(jìn)行說(shuō)明。響應(yīng)于此戲劇性信號(hào)，該生物體切斷這樣一個(gè)可選的方案為老化，動(dòng)員以這樣的方式附加儲(chǔ)備生存。類(lèi)似的解釋是假設(shè)為重肌肉工作，降低或在外部溫度的上升，少量代謝毒物（激效），低劑量的輻射，以及其它有害事件老化保護(hù)作用。與此相反，有時(shí)某些正信號(hào)可以通過(guò)抑制在個(gè)人誰(shuí)是對(duì)社區(qū)（例如，老化保護(hù)心理因素）有用老化方案延長(zhǎng)壽命。同樣地，危險(xiǎn)的個(gè)體可以通過(guò)程序性死亡是由于progeric心理因素操作消除。在關(guān)于其老化生物體的最終決定所有這些信號(hào)的結(jié)果的相互作用 - 加速或減速這個(gè)過(guò)程。因此，矛盾的是，這樣的最初反作用程序作為老化似乎是對(duì)個(gè)人有用的，因?yàn)樵摮绦蚩梢躁P(guān)閉由個(gè)人在一定的時(shí)間內(nèi)，一個(gè)動(dòng)作，從而增加其資源在生活的關(guān)鍵時(shí)期。3. AbstractThe aggregation of -synuclein (-Syn) is linked to Parkinsons disease. The mechanism of early aggregation steps and the effect of pathogenic single-point mutations remain elusive. We report here a single-molecule fluorescence study of -Syn dimerization and the effect of mutations. Specific interactions between tethered fluorophore-free -Syn monomers on a substrate and fluorophore-labeled monomers diffusing freely in solution were observed using total internal reflection fluorescence microscopy. The results showed that wild-type (WT) -Syn dimers adopt two types of dimers. The lifetimes of type 1 and type 2 dimers were determined to be 197 3ms and 3334 145ms, respectively. All three of the mutations used, A30P, E46K, and A53T, increased the lifetime of type 1 dimer and enhanced the relative population of type 2 dimer, with type 1 dimer constituting the major fraction. The kinetic stability of type 1 dimers (expressed in terms of lifetime) followed the order A30P (693 14ms) E46K (292 5ms) A53T (226 6ms) WT (197 3ms). Type 2 dimers, which are more stable, had lifetimes in the range of several seconds. The strongest effect, observed for the A30P mutant, resulted in a lifetime 3.5 times higher than observed for the WT type 1 dimer. This mutation also doubled the relative fraction of type 2 dimer. These data show that single-point mutations promote dimerization, and they suggest that the structural heterogeneity of -Syn dimers could lead to different aggregation pathways.抽象突觸核蛋白的聚集（-SYN）被鏈接到帕金森氏病。早期聚集步驟的機(jī)制和致病性的單點(diǎn)突變的效果仍然難以實(shí)現(xiàn)。我們?cè)谶@里報(bào)告-順二聚的單分子熒光研究和突變的效果。利用在襯底上系留的熒光團(tuán) - 自由-順單體和熒光團(tuán)標(biāo)記的單體在溶液中自由擴(kuò)散之間的特異性相互作用，觀察全內(nèi)反射熒光顯微鏡。結(jié)果表明，野生型（WT）-順二聚體采用兩種類(lèi)型的二聚體。 1型和2型二聚體的壽命被確定為1973毫秒和3334145毫秒，分別。所有三個(gè)使用，A30P，E46K和A53T突變，增加1型二聚體的壽命和增強(qiáng)的2型二聚體的相對(duì)群體，與構(gòu)成主要部分1型二聚體。 1型二聚體的動(dòng)力學(xué)穩(wěn)定性（在壽命方面表示）依次為A30P（69314毫秒） E46K（2925毫秒） A53T（2266毫秒） WT（1973毫秒）。 2型二聚體，這是更穩(wěn)定的，在幾秒鐘的范圍內(nèi)有壽命。最強(qiáng)的效果，觀察到的A30P突變，導(dǎo)致終生3.5倍以上觀察到的野生1型二聚體。這種突變也加倍的2型二聚體的相對(duì)分?jǐn)?shù)。這些數(shù)據(jù)表明，單點(diǎn)突變促進(jìn)二聚化，并且它們表明，-順二聚體的結(jié)構(gòu)異質(zhì)性可能會(huì)導(dǎo)致不同的聚合途徑。4. AbstractEquinatoxin II (EqtII) is a soluble, 20kDa pore-forming protein toxin isolated from the sea anemone Actinia equina. Although pore formation has long been known to occur in distinct stages, including monomeric attachment to phospholipid membranes followed by detachment of the N-terminal helical domain and oligomerization into the final pore assembly, atomistic-level detail of the protein-lipid interactions underlying these events remains elusive. Using high-resolutionsolution state NMR of uniformly-15N-labeled EqtII at the critical micelle concentration of dodecylphosphocholine, we have mapped the lipid-binding site throughchemicalshift perturbations. Subsequent docking of an EqtII monomer onto a dodecylphosphocholine micelle, followed by 400ns of all-atom molecular dynamics simulation, saw several high-occupancylipid-binding pockets stabilized by cation-, hydrogen bonding, and hydrophobic interactions; and stabilization of the loop housing the conserved arginine-glycine-aspartate motif. Additional simulation of EqtII with an N-acetyl sphingomyelin micelle, for which high-resolution NMR data cannot be obtained due to aggregate formation, revealed that sphingomyelin specificity might occur via hydrogen bonding to the 3-OH and 2-NH groups unique to the ceramide backbone byside chains of D109 and Y113; and main chains of P81 and W112. Furthermore, a binding pocket formed by K30, K77, and P81, proximate to the hinge region of the N-terminal helix, was identified and may be implicated in triggering pore formation.Copyright 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.抽象Equinatoxin二（EqtII）是可溶的，20kDa的孔形成蛋白毒素從?？？R尾隔離。雖然孔形成早已知道發(fā)生在不同的階段，包括單體附著到磷脂膜隨后的N末端螺旋結(jié)構(gòu)域和寡聚化到最終孔隙組件的剝離，蛋白質(zhì) - 脂質(zhì)相互作用的原子級(jí)細(xì)節(jié)底層這些事件仍然遙遙無(wú)期。使用均勻-15N標(biāo)記在dodecylphosphocholine的臨界膠束濃度EqtII高分辨率溶液狀態(tài)核磁共振，我們已制訂通過(guò)化學(xué)位移擾動(dòng)脂質(zhì)結(jié)合位點(diǎn)。隨后一個(gè)EqtII單體到dodecylphosphocholine膠束的對(duì)接，接著400納秒的所有原子的分子動(dòng)力學(xué)模擬，鋸由陽(yáng)離子，氫鍵，疏水相互作用穩(wěn)定的幾個(gè)高占用脂質(zhì)結(jié)合口袋;和環(huán)形外殼的保守精氨酸 - 甘氨酸 - 天門(mén)冬氨酸基序的穩(wěn)定化。 EqtII的附加模擬具有N-乙酰神經(jīng)鞘磷脂膠束，為此高分辨率NMR數(shù)據(jù)不能由于聚集體形成得到，表明鞘磷脂特異性可能通過(guò)氫鍵發(fā)生于3-OH和2-NH基團(tuán)所特有的神經(jīng)酰胺骨干由D109與Y113的側(cè)鏈;與P81和W112的主鏈。此外，通過(guò)K30，K77，和P81，靠近N-末端螺旋的鉸鏈區(qū)形成的結(jié)合口袋，被確定，并且可以在觸發(fā)孔形成受到牽連。版權(quán)所有2015年生物物理學(xué)會(huì)。發(fā)布時(shí)間由Elsevier公司保留所有權(quán)利。5. AbstractSwitchable proteins that can be regulated through exogenous or endogenous inputs have a broad range of biotechnological and biomedical applications. Here we describe the design of switchable enzymes based on an ensemble allosteric model. First, we insert an enzyme domain into an effector-binding domain such that both domains remain functionally intact. Second, we induce the fusion to behave as a switch through the introduction of conditional conformational flexibility designed to increase the conformational entropy of the enzyme domain in a temperature- or pH-dependent fashion. We confirm the switching behaviour in vitro and in vivo. Structural and thermodynamic studies support the hypothesis that switching result from an increase in conformational entropy of the enzyme domain in the absence of effector. These results support the ensemble model of allostery and embody a strategy for the design of protein switches.抽象可以通過(guò)外源或內(nèi)源的輸入來(lái)調(diào)節(jié)切換蛋白質(zhì)具有廣泛的生物技術(shù)和生物醫(yī)學(xué)應(yīng)用。在這里，我們描述了基于合奏變構(gòu)模型切換酶的設(shè)計(jì)。首先，我們將插入的酶域到一個(gè)效應(yīng)子 - 結(jié)合結(jié)構(gòu)域，使得這兩個(gè)結(jié)構(gòu)域在功能上保持不變。第二，我們誘導(dǎo)的融合表現(xiàn)為通過(guò)引入設(shè)計(jì)用于增加在一個(gè)溫度或pH依賴(lài)性方式酶結(jié)構(gòu)域的構(gòu)象熵條件的構(gòu)象靈活性的開(kāi)關(guān)。我們證實(shí)在體外和體內(nèi)的開(kāi)關(guān)行為。結(jié)構(gòu)和熱力學(xué)研究支持切換結(jié)果從增加在沒(méi)有效應(yīng)的酶結(jié)構(gòu)域的構(gòu)象熵的假說(shuō)。這些結(jié)果支持變構(gòu)的集成模型，體現(xiàn)了戰(zhàn)略的蛋白質(zhì)開(kāi)關(guān)的設(shè)計(jì)。6. AbstractOrganic acids, which are chemically synthesized, are also natural intermediates in the metabolic pathways of microorganisms, among which the tricarboxylic acid (TCA) cycle is the most crucial route existing in almost all living organisms. Organic acids in the TCA cycle include citric acid, -ketoglutaric acid, succinic acid, fumaric acid, l-malic acid, and oxaloacetate, which are building-block chemicals with wide applications and huge markets. In this review, we summarize the synthesis pathways of these organic acids and review recent advances in metabolic engineering strategies that enhance organic acids production. We also propose further improvements for the production of organic acids with systems and syntheticbiology-guided metabolic engineering strategies.抽象有機(jī)酸，其是化學(xué)合成的，也都在微生物的代謝途徑，其中所述三羧酸（TCA）循環(huán)是存在于幾乎所有生物的最重要途徑自然中間體。在TCA循環(huán)中的有機(jī)酸包括檸檬酸，酮戊二酸，琥珀酸，富馬酸，L-蘋(píng)果酸，和草酰乙酸鹽，它們是具有廣泛的應(yīng)用和巨大的市場(chǎng)建立塊的化學(xué)品。在這次審查中，我們總結(jié)這些有機(jī)酸的合成途徑和審查的最新進(jìn)展代謝工程戰(zhàn)略，提高有機(jī)酸生產(chǎn)。我們還提出進(jìn)一步的改進(jìn)，為生產(chǎn)具有的系統(tǒng)和合成生物學(xué)制導(dǎo)代謝工程策略有機(jī)酸。7. AbstractMembers of the human microbiota are increasingly being correlated to human health and disease states, but the majority of the underlying microbial metabolites that regulate host-microbe interactions remain largely unexplored. Select stra