BACKGROUND & AIMS: The present paper describes the sensitivity of the mitochondrial nicotinamide nucleotide transhydrogenase (EC 1.6.1.1) to oxidative modification, and the effects of endogenous ubiquinol on this modification. A comparison is made between the effects of treatment with ADP-Fe3+ and ascorbate and with peroxynitrite, using kinetic, electrophoretic, and immunological analyses, together with lipid peroxidation measurements. The transhydrogenase was inactivated by both types of oxidative modification, but apparently through different mechanisms. Ubiquinol protected the enzyme against inactivation only when the modification was caused by ADP-Fe3+ and ascorbate treatment. Kinetic measurements revealed a threefold increase of the Km value of the enzyme for NADPH after exposure to ADP-Fe3+ and ascorbate, and a twofold increase of the Km values for both NADH and NADPH after exposure to peroxynitrite. NAD(H) exerted a protection against trans-hydrogenase inactivation when added to the preincubation in the case of peroxynitrite, but neither NAD(H) or NADP(H) protected in the case of ADP-Fe3+ and ascorbate. Using immunoblotting it was shown that the enzyme became both aggregated and fragmented, although to different extents, depending on the oxidative system used. Again, ubiquinol prevented these effects only in the case of ADP-Fe3+ and ascorbate treatment. Furthermore, there occurred a striking decrease in the 66-kDa trypsin fragment after exposure of the enzyme to ADP-Fe3+ and ascorbate, and of the 48-kDa trypsin fragment after exposure to peroxynitrite. It is concluded that the mitochondrial nicotinamide nucleotide transhydrogenase is sensitive to oxidative stress and that the mechanism underlying this can vary according to the challenge to which the enzyme is exposed. Endogenous ubiquinol may play a role in protecting the enzyme against agents perturbing the lipid phase of the membrane.

背景与目标： 本文描述了线粒体烟酰胺核苷酸转酸酶 (EC 1.6.1.1) 对氧化修饰的敏感性，以及内源性泛醇对这种修饰的影响。使用动力学，电泳和免疫学分析以及脂质过氧化测量，比较了ADP-Fe3和抗坏血酸盐和过氧亚硝酸盐的治疗效果。两种类型的氧化修饰都使转酸酶失活，但显然是通过不同的机制。泛醇仅当修饰是由ADP-Fe3 + 和抗坏血酸处理引起时才保护酶免于失活。动力学测量显示，暴露于ADP-Fe3和抗坏血酸盐后，NADPH的酶Km值增加了三倍，而暴露于过氧亚硝酸盐后，NADH和NADPH的Km值均增加了两倍。在过氧亚硝酸盐的情况下，将NAD(H) 添加到预孵育中时对反式氢化酶失活具有保护作用，但在ADP-Fe3和抗坏血酸盐的情况下，NAD(H) 或NADP(H) 均未受到保护。使用免疫印迹显示，该酶既聚集又破碎，尽管程度不同，具体取决于所使用的氧化系统。同样，泛醇仅在ADP-Fe3 + 和抗坏血酸处理的情况下阻止了这些作用。此外，酶暴露于ADP-Fe3和抗坏血酸酯后，66 kDa胰蛋白酶片段显着减少，而48 kDa胰蛋白酶片段暴露于过氧亚硝酸盐后显着减少。结论是，线粒体烟酰胺核苷酸转酸酶对氧化应激敏感，其潜在机制可能会根据酶所面临的挑战而变化。内源性泛醇可能在保护酶免受干扰膜脂质相的作用中发挥作用。

BACKGROUND & AIMS: :A preparation containing the Mr 13,400 protein (subunit VI), phospholipid, and ubiquinone was isolated from bovine heart mitochondrial ubiquinol-cytochrome c reductase by a procedure involving Triton X-100 and urea solubilization, calcium phosphate-cellulose column chromatography at different pHs, acetone precipitation, and decanoyl-N-methylglucamide-sodium cholate extraction. The protein in this preparation corresponds to subunit VI of ubiquinol-cytochrome c reductase resolved in the sodium dodecyl sulfate-polyacrylamidce gel electrophoresis system of Schägger et al. (1987, FEBS Lett. 21, 161-168) and has the same amino acid sequence as that of the Mr 13,400 protein reported by Wakabayashi et al. (1985, J. Biol. Chem. 260, 337-343). The phospholipid and ubiquinone present in the preparation copurify with but are not intrinsic components of, the Mr 13,400 protein. This preparation has a potency and behavior identical to that of a free phospholipid preparation in restoring activity to delipidated ubiquinol-cytochrome c reductase. Antibodies against Mr 13,400 react only with Mr 13,400 protein and complexes which contain it. They do not inhibit intact, lipid-sufficient ubiquinol-cytochrome c reductase. However, when delipidated ubiquinol-cytochrome c reductase is incubated with antibodies prior to reconstitution with phospholipid, a 55% decrease in the restoration activity is observed, indicating that the catalytic site-related epitopes of the Mr 13,400 protein are buried in the phospholipid environment. Antibodies against Mr 13,400 cause an increase of apparent Km for ubiquinol-2 in ubiquinol-cytochrome c reductase. When mitoplasts or submitochondrial particles are exposed to a horseradish peroxidase conjugate of the Fab' fragment of anti-Mr 13,400 antibodies, peroxidase activity is found mainly in the submitochondrial particles preparation; little activity is detected in mitoplasts. This suggests that the Mr 13,400 protein is extruded toward the matrix side of the membrane.

背景与目标： : 通过涉及Triton X-100和尿素增溶，磷酸钙-纤维素柱色谱在不同ph下，丙酮沉淀，从牛心线粒体泛醇-细胞色素c还原酶中分离出含有Mr 13,400蛋白 (亚基VI)，磷脂和泛醌的制剂，和癸酰基-N-甲基葡糖酰胺-胆酸钠提取。该制剂中的蛋白质对应于在sch ä gger等人的十二烷基硫酸钠-聚丙烯酰胺凝胶电泳系统中解析的泛醇-细胞色素c还原酶的亚基VI (1987，FEBS Lett. 21，161-168)，并且具有与Wakabayashi等人报道的Mr 13,400蛋白相同的氨基酸序列 (1985，J. Biol. Chem. 260，337-343)。制剂中存在的磷脂和泛醌与Mr 13,400蛋白共纯化但不是固有成分。该制剂在恢复脱脂的泛醇-细胞色素c还原酶的活性方面具有与游离磷脂制剂相同的效力和行为。抗Mr 13,400的抗体仅与Mr 13,400蛋白和含有它的复合物反应。它们不抑制完整的，脂质充足的泛醇-细胞色素c还原酶。然而，当脱脂的泛醇-细胞色素c还原酶在用磷脂重建之前与抗体孵育时，观察到恢复活性的55% 降低，表明Mr 13,400蛋白的催化位点相关表位被掩埋在磷脂环境中。抗Mr 13,400的抗体导致泛醇-细胞色素c还原酶中ubiquinol-2的表观Km增加。当mitoposal或线粒体颗粒暴露于抗Mr 13,400抗体的Fab' 片段的辣根过氧化物酶缀合物时，过氧化物酶活性主要存在于线粒体颗粒制剂中; 在mitoposal中检测到的活性很少。这表明Mr 13,400蛋白向膜的基质侧挤出。

BACKGROUND & AIMS: Cytochrome bo is a member of the heme-copper terminal oxidase superfamily and serves as a four-subunit ubiquinol oxidase in the aerobic respiratory chain of Escherichia coli. To probe the location and structural properties of the ubiquinol oxidation site, we isolated and characterized five or 10 spontaneous mutants resistant to either 2,6-dimethyl-1,4-benzoquinone, 2,6-dichloro-4-nitrophenol, or 2,6-dichloro-4-dicyanovinylphenol, the potent competitive inhibitors for the oxidation of ubiquinol-1 [Sato-Watanabe, M., Mogi, T., Miyoshi, H., Iwamura, H., Matsushita, K., Adachi, O., and Anraku, Y. (1994) J. Biol. Chem. 269, 28899-28907]. Analyses of the growth yields and the ubiquinol-1 oxidase activities of the mutant membranes showed that the mutations increased the degree of the resistance to the selecting compounds. Notably, several mutants showed the cross-resistance. These data indicate that the binding sites for substrate and the competitive inhibitors are partially overlapped in the ubiquinol oxidation site. All the mutations were linked to the expression vector, and 23 mutations examined were all present in the C-terminal hydrophilic domain (Pro96-His315) of subunit II. Sequencing analysis revealed that seven mutations examined are localized near both ends of the cupredoxin fold. Met248Ile, Ser258Asn, Phe281Ser, and His284Pro are present in a quinol oxidase-specific (Qox) domain and proximal to low-spin heme b in subunit I and the lost CuA site in subunit II, whereas Ile129Thr, Asn198Thr, and Gln233His are rather scattered in a three-dimensional structure and closer to transmembrane helices of subunit II. Our data suggest that the Qox domain and the CuA end of the cupredoxin fold provide the quinol oxidation site and are involved in electron transfer to the metal centers in subunit I.

背景与目标： 细胞色素bo是血红素铜末端氧化酶超家族的成员，在大肠杆菌的有氧呼吸链中充当四亚基泛醇氧化酶。为了探究泛醇氧化位点的位置和结构性质，我们分离并鉴定了5个或10个对2,6-二甲基-1,4-苯醌，2,6-二氯-4-硝基苯酚或2,6-二氯-4-二氰基苯酚具有抗性的自发突变体，ubiquinol-1的有效竞争抑制剂 [Sato-Watanabe，M.，Mogi，T.，三好，H.，岩村，H.，松下，K.，足立，O.，和安乐，Y. (1994) J. Biol. Chem. 269，28899-28907]。对突变膜的生长产量和ubiquinol-1氧化酶活性的分析表明，突变增加了对选择化合物的抗性程度。值得注意的是，几个突变体显示出交叉抗性。这些数据表明，底物和竞争性抑制剂的结合位点在泛醇氧化位点部分重叠。所有突变均与表达载体连接，并且所检查的23个突变均存在于亚基II的C末端亲水结构域 (Pro96-His315) 中。测序分析显示，所检查的七个突变位于cupredoxin折叠的两端附近。Met248Ile，Ser258Asn，Phe281Ser和His284Pro存在于喹啉氧化酶特异性 (Qox) 结构域中，并且靠近亚基I中的低自旋血红素b和亚基II中丢失的CuA位点，而Ile129Thr，Asn198Thr，gln233His相当分散在三维结构中，更接近亚基II的跨膜螺旋。我们的数据表明，cupredoxin折叠的Qox结构域和CuA末端提供了quinol氧化位点，并参与了向亚基I中的金属中心的电子转移。

BACKGROUND & AIMS: The cytochrome bo ubiquinol oxidase from Escherichia coli is a five-subunit enzyme which is a member of the superfamily of heme-copper respiratory oxidases. Three of the subunits (I, II, and III) are homologous to the three mitochondrial encoded subunits of the eukaryotic aa3-type cytochrome c oxidase. Subunits, I, II, and III of the eukaryotic oxidase contain 12, 2, and 7 putative transmembrane spans, respectively. The hydropathy profiles of the subunits of most other members of this oxidase superfamily are consistent with these structures. However, subunit I from the E. coli oxidase contains 15 transmembrane spans, with one additional span at the N-terminus and two additional spans at the C-terminus in comparison to the eukaryotic oxidase. The additional transmembrane helix at the N-terminus predicts that the amino terminal residue should be on the periplasmic side of the membrane. By deleting the intergenic region between the cyoA and cyoB genes, an in-frame fusion between subunit II (cyoA) and subunit I (cyoB) was generated. This links the C-terminus of subunit II, known to be on the periplasmic side of the membrane, to the N-terminus of subunit I. The resulting oxidase is fully active, and supports the toplogical folding pattern previously suggested for subunit I with the N-terminus in the periplasm. Whereas subunit I of the E. coli oxidase has two additional membrane-spanning helices at the C-terminus, subunit III has two fewer helices than does the corresponding subunit III of the eukaryotic oxidase.(ABSTRACT TRUNCATED AT 250 WORDS)

背景与目标： 来自大肠杆菌的细胞色素bo泛醇氧化酶是一种五亚基酶，是血红素铜呼吸氧化酶超家族的成员。三个亚基 (I，II和III) 与真核aa3-type细胞色素c氧化酶的三个线粒体编码亚基同源。真核氧化酶的亚基I，II和III分别包含12、2和7个推定的跨膜跨度。该氧化酶超家族大多数其他成员的亚基的亲水谱与这些结构一致。然而，与真核氧化酶相比，来自大肠杆菌氧化酶的亚基I包含15个跨膜跨度，在N末端增加一个跨度，在C末端增加两个跨度。N末端的附加跨膜螺旋预测氨基末端残基应在膜的周质侧。通过删除cyoA和cyoB基因之间的基因间区域，生成了亚基II (cyoA) 和亚基I (cyoB) 之间的框架内融合。这将亚基II的C端 (已知位于膜的周质侧) 连接到亚基I的N端。所得的氧化酶具有完全活性，并支持先前建议的亚基I在周质中具有N末端的顶折叠模式。大肠杆菌氧化酶的亚基I在C末端有两个额外的跨膜螺旋，而亚基III比真核氧化酶的相应亚基III少两个螺旋。(摘要截短于250字)

BACKGROUND & AIMS: STUDY OBJECTIVE:To assess the effects of fenofibrate therapy on concentrations of plasma ubiquinol-10 and ubiquinone-10-the reduced and oxidized forms, respectively, of coenzyme Q(10). DESIGN:Prospective, open-label, non-controlled study. SETTING:University clinic and laboratory. PATIENTS:Eighteen patients with hyperlipidemia and type 2 diabetes mellitus. INTERVENTION:Patients received fenofibrate 150 mg/day for 12 weeks. MEASUREMENTS AND MAIN RESULTS:Metabolic parameters were assessed 4, 8, and 12 weeks after the start of fenofibrate treatment. Plasma ubiquinol-10 and ubiquinone-10 levels were measured by reverse-phase high-performance liquid chromatography. At 4, 8, and 12 weeks, significant reductions in fasting triglyceride levels and significant increases in high-density lipoprotein cholesterol levels were noted. Total cholesterol, low-density lipoprotein cholesterol, fasting plasma glucose, and adiponectin levels, however, did not change significantly. Plasma ubiquinol-10 concentrations significantly increased after 8 and 12 weeks (p<0.05 for both), whereas ubiquinone-10 concentrations tended to decrease, especially at 12 weeks. CONCLUSION:Our findings suggest that fenofibrate may help produce energy or prevent oxidation by increasing plasma ubiquinol-10 concentration; this effect may protect against the development and progression of atherosclerosis. In addition, treatment with fenofibrate demonstrated a favorable effect on serum lipid parameters.

背景与目标：

BACKGROUND & AIMS: :Deletion of QCR9, the nuclear gene encoding subunit 9 of the mitochondrial cytochrome bc1 complex in Saccharomyces cerevisiae, results in inactivation of the bc1 complex and inability of the yeast to grow on non-fermentable carbon sources. The loss of bc1 complex activity is due to loss of electron transfer activity at the ubiquinol oxidase site (center P) in the complex. Electron transfer at the ubiquinone reductase site (center N), is unaffected by the loss of subunit 9, but the extent of cytochrome b reduction is diminished. This is the first instance in which a supernumerary polypeptide, lacking a redox prosthetic group, has been shown to be required for an electron transfer reaction within the cytochrome bc1 complex.

背景与目标： : QCR9 (酿酒酵母中线粒体细胞色素bc1复合物的编码亚基9的核基因) 的缺失，导致bc1复合物失活，并且酵母无法在不可发酵的碳源上生长。bc1复合物活性的丧失是由于复合物中泛醇氧化酶位点 (中心P) 的电子转移活性的丧失。泛醌还原酶位点 (中心N) 的电子转移不受亚基9损失的影响，但细胞色素b还原的程度减少了。这是第一个实例，其中缺少氧化还原假体基团的多余多肽已被证明是细胞色素bc1复合物内电子转移反应所必需的。

BACKGROUND & AIMS: :The R481 residue of cytochrome bo(3) ubiquinol oxidase from E. coli is highly conserved in the heme-copper oxidase superfamily. It has been postulated to serve as part of a proton loading site that regulates proton translocation across the protein matrix of the enzyme. Along these lines, proton pumping efficiency has been demonstrated to be abolished in many R481 mutants. However, R481Q in bo(3) from E. coli has been shown to be fully functional, implying that the positive charge of the arginine is not required for proton translocation [ Puustinen , A. and Wikstrom , M. ( 1999 ) Proc. Natl. Acad. Sci. U.S.A. 96 , 35 - 37 ]. In an effort to delineate the structural role of R481 in the bo(3) oxidase, we used resonance Raman spectroscopy to compare the nonfunctional R481L mutant and the functional R481Q mutant, to the wild type protein. Resonance Raman data of the oxidized and reduced forms of the R481L mutant indicate that the mutation introduces changes to the heme o(3) coordination state, reflecting a change in position and/or coordination of the Cu(B) located on the distal side of heme o(3), although it is approximately 10 A away from R481. In the reduced-CO adduct of R481L, the frequencies of the Fe-CO and C-O stretching modes indicate that, unlike the wild type protein, the Cu(B) is no longer close to the heme-bound CO. In contrast, resonance Raman data obtained from the various oxidation and ligation states of the R481Q mutant are similar to those of the wild type protein, except that the mutation causes an enhancement of the relative intensity of the beta conformer of the CO-adduct, indicating a shift in the equilibrium between the alpha and beta conformers. The current findings, together with crystallographic structural data of heme-copper oxidases, indicate that R481 plays a keystone role in stabilizing the functional structure of the Cu(B) site through a hydrogen bonding network involving ordered water molecules. The implications of these data on the proton translocation mechanism are considered.

背景与目标： : 来自大肠杆菌的细胞色素bo(3) 泛醇氧化酶的R481残基在血红素铜氧化酶超家族中高度保守。据推测，它是质子加载位点的一部分，该位点调节质子在酶的蛋白质基质上的转运。按照这些思路，已证明在许多R481突变体中都可以消除质子泵送效率。然而，来自大肠杆菌的bo(3) 中的R481Q已被证明具有完全功能，这意味着质子易位不需要精氨酸的正电荷 [Puustinen，A.和Wikstrom，M、 (1999) Proc. Natl. Acad. Sci. U.S.A.96,35-37]。为了描述R481在bo(3) 氧化酶中的结构作用，我们使用共振拉曼光谱法将非功能性R481L突变体和功能性R481Q突变体与野生型蛋白进行了比较。R481L突变体的氧化和还原形式的共振拉曼数据表明，该突变引入了血红素o(3) 配位状态的变化，反映了位于血红素o(3) 远端的Cu(B) 的位置和/或配位的变化，尽管它与r481相距约10 A。在R481L的还原CO加合物中，Fe-CO和c-o拉伸模式的频率表明，与野生型蛋白不同，Cu(B) 不再接近血红素结合的CO。相反，从R481Q突变体的各种氧化和连接状态获得的共振拉曼数据与野生型蛋白质的共振拉曼数据相似，只是该突变导致共加合物的 β 构象体的相对强度增强，表明 α 和 β 构象异构体之间的平衡发生了变化。当前的发现以及血红素-铜氧化酶的晶体学结构数据表明，R481通过涉及有序水分子的氢键网络在稳定Cu(B) 位点的功能结构中起着关键作用。考虑了这些数据对质子易位机制的影响。

BACKGROUND & AIMS: :Dietary restriction (DR) is a robust intervention that extends both health span and life span in many organisms. Ubiquinol and ubiquinone represent the reduced and oxidized forms of coenzyme Q (CoQ). CoQ plays a central role in energy metabolism and functions in several cellular processes including gene expression. Here we used the model organism Caenorhabditis elegans to determine level and redox state of CoQ and expression of genes in response to DR. We found that DR down-regulates the steady-state expression levels of several evolutionary conserved genes (i.e. coq-1) that encode key enzymes of the mevalonate and CoQ-synthesizing pathways. In line with this, DR decreases the levels of total CoQ and ubiquinol. This CoQ-reducing effect of DR is obvious in adult worms but not in L4 larvae and is also evident in the eat-2 mutant, a genetic model of DR. In conclusion, we propose that DR reduces the level of CoQ and ubiquinol via gene expression in the model organism C. elegans.

背景与目标： : 饮食限制 (DR) 是一种强有力的干预措施，可以延长许多生物的健康寿命和寿命。泛醌和泛醌代表辅酶q (CoQ) 的还原和氧化形式。CoQ在能量代谢中起着核心作用，并在包括基因表达在内的几个细胞过程中发挥作用。在这里，我们使用秀丽隐杆线虫的模式生物来确定CoQ的水平和氧化还原状态以及响应DR的基因表达。我们发现DR下调了几个进化保守基因 (即coq-1) 的稳态表达水平，这些基因编码甲羟戊酸和辅酶q合成途径的关键酶。与此一致，DR降低了总CoQ和泛醇的水平。DR的这种降低CoQ的作用在成年蠕虫中很明显，但在L4幼虫中不明显，在DR的遗传模型eat-2突变体中也很明显。总之，我们建议DR通过模式生物秀丽隐杆线虫中的基因表达降低CoQ和泛醇的水平。

BACKGROUND & AIMS: OBJECTIVES:Physical exercise significantly impacts the biochemistry of the organism. Ubiquinone is a key component of the mitochondrial respiratory chain and ubiquinol, its reduced and active form, is an emerging molecule in sport nutrition. The aim of this study was to evaluate the effect of ubiquinol supplementation on biochemical and oxidative stress indexes after an intense bout of exercise. METHODS:21 male young athletes (26 + 5 years of age) were randomized in two groups according to a double blind cross-over study, either supplemented with ubiquinol (200 mg/day) or placebo for 1 month. Blood was withdrawn before and after a single bout of intense exercise (40 min run at 85% maxHR). Physical performance, hematochemical parameters, ubiquinone/ubiquinol plasma content, intracellular reactive oxygen species (ROS) level, mitochondrial membrane depolarization, paraoxonase activity and oxidative DNA damage were analyzed. RESULTS:A single bout of intense exercise produced a significant increase in most hematochemical indexes, in particular CK and Mb while, on the contrary, normalized coenzyme Q10 plasma content decreased significantly in all subjects. Ubiquinol supplementation prevented exercise-induced CoQ deprivation and decrease in paraoxonase activity. Moreover at a cellular level, in peripheral blood mononuclear cells, ubiquinol supplementation was associated with a significant decrease in cytosolic ROS while mitochondrial membrane potential and oxidative DNA damage remained unchanged. DISCUSSION:Data highlights a very rapid dynamic of CoQ depletion following intense exercise underlying an increased demand by the organism. Ubiquinol supplementation minimized exercise-induced depletion and enhanced plasma and cellular antioxidant levels but it was not able to improve physical performance indexes or markers of muscular damage.

背景与目标：

BACKGROUND & AIMS: :Oxygen/nitrogen reactive species (ROS/RNS) are currently implicated in the pathogenesis of ulcerative colitis, drawing attention on the potential prophylactic and healing properties of antioxidants, scavengers, chelators. We evaluated the possible protective/curative effects of a natural antioxidant preparation based on Aloe vera and ubiquinol, against intestinal inflammation, lesions, and pathological alterations of the intestinal electrophysiological activity and motility, in a rat model of DSS-induced colitis. 5% dextrane sulfate (DDS) (3 days), followed by 1% DSS (4 days) was administered in drinking water. The antioxidant formulation (25 mg/kg) was delivered with a pre-treatment protocol, or simultaneously or post-colitis induction. Spontaneous and acetylcholine-stimulated electrical activity were impaired in the small intestine and in distal colon, upon exposure to DSS only. Severe inflammation occurred, with increased myeloperoxidase activity, and significant alterations of the oxidant/antioxidant status in colonic tissue and peritoneal cells. Lipoperoxidation, superoxide production, glutathione peroxidase and glutathione-S-transferase activities, and reduced glutathione content increased, whilst superoxide dismutase and catalase activities were sharply suppressed in colon tissue. ROS/RNS formation in peritoneal cells was strongly inhibited. Inflammation, electrical/mechanical impairment in the gut, and a great majority of oxidative stress parameters were improved substantially by pre-treatment with the antioxidant preparation, but not by simultaneous administration or post-treatment.

背景与目标： : 氧/氮反应性物种 (ROS/RNS) 目前与溃疡性结肠炎的发病机理有关，引起人们对抗氧化剂，清除剂，螯合剂的潜在预防和治疗特性的关注。在DSS诱导的结肠炎大鼠模型中，我们评估了基于芦荟和泛醇的天然抗氧化剂制剂对肠道炎症，病变以及肠道电生理活性和运动性的病理改变的可能的保护/治疗作用。5% 硫酸右旋糖酐 (DDS) (3天)，然后1% DSS (4天) 在饮用水中给药。抗氧化剂制剂 (25 mg/kg) 与治疗前方案一起递送，或同时或在结肠炎诱导后递送。仅暴露于DSS后，小肠和远端结肠的自发和乙酰胆碱刺激的电活动受损。发生严重炎症，髓过氧化物酶活性增加，结肠组织和腹膜细胞的氧化剂/抗氧化剂状态明显改变。结肠组织中的脂质过氧化，超氧化物产生，谷胱甘肽过氧化物酶和谷胱甘肽S-转移酶活性以及还原的谷胱甘肽含量增加，而超氧化物歧化酶和过氧化氢酶活性急剧受到抑制。腹膜细胞中ROS/RNS的形成受到强烈抑制。通过使用抗氧化剂制剂进行预处理，但不能通过同时给药或后处理，大大改善了肠道中的炎症，电/机械损伤以及绝大多数氧化应激参数。

BACKGROUND & AIMS: :Ubiquinone is a lipid antioxidant, and a novel liquid ubiquinol (a hydro-soluble, reduced form of coenzyme Q10) supplement was recently developed. The purpose of this study was to examine the levels of glucose, lipids and antioxidant capacity of type 2 diabetes patients after liquid ubiquinol supplementation. This study was designed as a randomised, double-blind, placebo-controlled trial. In all, fifty participants were randomly assigned to a placebo (n 25) or liquid ubiquinol (100 mg/d, n 25) group, and the intervention lasted for 12 weeks. Plasma coenzyme Q10, glucose homoeostasis parameters, lipid profiles, oxidative stress and antioxidative enzyme activities were measured during the study. After 12 weeks of supplementation, glyco Hb (HbA1c) value was significantly decreased in the liquid ubiquinol group (P=0·03), and subjects in the liquid ubiquinol group had significantly lower anti-glycaemic medication effect scores (MES) compared with those in the placebo group (P=0·03). The catalase (P<0·01) and glutathione peroxidase (P=0·03) activities were increased significantly after supplementation. Plasma coenzyme Q10 was correlated with the insulin level (P=0·05), homoeostatic model assessment-insulin resistance (P=0·07), quantitative insulin sensitivity check index (P=0·03) and the anti-hyperglycaemic agents' MES (P=0·03) after supplementation. Lipid profiles did not change after supplementation; however, the subjects in the placebo group had a significantly lower level of HDL-cholesterol after 12 weeks of intervention. In conclusion, oral intake of 100 mg/d liquid ubiquinol might benefit type 2 diabetes patients by increasing antioxidant enzyme activity levels, reducing HbA1c levels and maintaining HDL-cholesterol levels.

背景与目标： : 泛醌是一种脂质抗氧化剂，最近开发了一种新型液体泛醌 (辅酶Q10的水溶性还原形式) 补充剂。这项研究的目的是检查补充液体泛醇后2型糖尿病患者的葡萄糖，脂质和抗氧化能力水平。这项研究被设计为一项随机，双盲，安慰剂对照试验。共有50名参与者被随机分配到安慰剂 (n 25) 或液体泛醇 (100 mg/d，n 25) 组，干预持续12周。在研究过程中测量了血浆辅酶Q10，葡萄糖稳态参数，脂质分布，氧化应激和抗氧化酶活性。补充12周后，液体泛醇组glyco Hb (HbA1c) 值显著降低 (P = 0·03)，与安慰剂组相比，液体泛醇组的受试者抗血糖作用评分 (MES) 明显降低 (P = 0·03)。添加后，过氧化氢酶 (P<0·01) 和谷胱甘肽过氧化物酶 (P = 0·03) 活性显着增加。补充血浆辅酶Q10与胰岛素水平 (P = 0·05) 、胰岛素抵抗 (P = 0·07) 、胰岛素敏感性定量检查指数 (P = 0·03) 和抗高血糖药的MES (P = 0·03) 相关。补充后血脂谱没有变化; 然而，安慰剂组的受试者在干预12周后HDL-胆固醇水平明显降低。总之，口服摄入100 mg/d液体泛醇可能通过增加抗氧化酶活性水平，降低HbA1c水平和维持HDL-胆固醇水平而有益于2型糖尿病患者。

BACKGROUND & AIMS: :The bacterial aerobic respiratory chain has a terminal oxidase of the heme-copper oxidase superfamily, comprised of cytochrome c oxidase (COX) and ubiquinol oxidase (UOX); UOX evolved from COX. Acetobacter pasteurianus, an α-Proteobacterial acetic acid bacterium (AAB), produces UOX but not COX, although it has a partial COX gene cluster, ctaBD and ctaA, in addition to the UOX operon cyaBACD. We expressed ctaB and ctaA genes of A. pasteurianus in Escherichia coli and demonstrated their function as heme O and heme A synthases. We also found that the absence of ctaD function is likely due to accumulated mutations. These COX genes are closely related to other α-Proteobacterial COX proteins. However, the UOX operons of AAB are closely related to those of the β/γ-Proteobacteria (γ-type UOX), distinct from the α/β-Proteobacterial proteins (α-type UOX), but different from the other γ-type UOX proteins by the absence of the cyoE heme O synthase. Thus, we suggest that A. pasteurianus has a functional γ-type UOX but has lost the COX genes, with the exception of ctaB and ctaA, which supply the heme O and A moieties for UOX. Our results suggest that, in AAB, COX was replaced by β/γ-Proteobacterial UOX via horizontal gene transfer, while the COX genes, except for the heme O/A synthase genes, were lost.

背景与目标： : 细菌需氧呼吸链具有血红素铜氧化酶超家族的末端氧化酶，由细胞色素c氧化酶 (COX) 和泛醇氧化酶 (UOX) 组成; UOX从COX进化而来。巴氏杆菌 (Acetobacter pasteurianus) 是一种 α-变形杆菌乙酸细菌 (AAB)，除了具有UOX操纵子cyaBACD之外，它还具有部分COX基因簇ctaBD和ctaA，但不产生COX。我们在大肠杆菌中表达了巴氏杆菌的ctaB和ctaA基因，并证明了它们作为血红素O和血红素A合酶的功能。我们还发现，ctaD功能的缺失可能是由于累积的突变。这些COX基因与其他 α-变形菌COX蛋白密切相关。然而，AAB的UOX操纵子与 β/γ-变形菌 (γ 型UOX) 密切相关，与 α/β-变形菌蛋白 (α 型UOX) 不同，但与其他 γ 型UOX蛋白不同的是，不存在cyoE血红素O合酶。因此，我们建议巴氏杆菌具有功能性 γ 型UOX，但已失去COX基因，但ctaB和ctaA除外，后者为UOX提供了血红素O和A部分。我们的结果表明，在AAB中，COX通过水平基因转移被 β/γ-变形杆菌UOX取代，而COX基因 (血红素O/A合酶基因除外) 丢失。

BACKGROUND & AIMS: :Generation of toxic oxygen metabolites followed by oxidant- and inflammatory-mediated tissue injury plays a crucial role in the pathogenesis of ischemia and reperfusion (IR). Ubiquinol, the reduced form of coenzyme Q10, is recognized for its potent antioxidant and anti-inflammatory properties in biological membranes. The present study was established to examine the possible protective effect of ubiquinol against renal IR injury. Groups of male Wistar rats were assigned into sham, ubiquinol, IR (45-min bilateral renal ischemia followed by 24-h reperfusion), and ubiquinol+ IR (ubiquinol 300 mg/kg given orally for 7 consecutive days before IR induction). Renal morphology, function, oxidative stress, and inflammatory markers were evaluated at the end of reperfusion. IR caused renal dysfunction as shown by significant increases in blood urea nitrogen, plasma creatinine, and a decrease in creatinine clearance. Light and electron microscopic examinations exhibited severe tubular damages and abnormal mitochondrial structure. IR-induced renal injuries were associated with significant increases in malondialdehyde, nitric oxide, tumor necrosis factor-α, but decreases in antioxidant thiols and superoxide dismutase. Pretreatment with ubiquinol obviously attenuated all the changes caused by IR, whereas it had no considerable effect in the sham-operated rats. These findings indicate that supplementation of ubiquinol prior to IR incidence confers functional and morphological protection to the ischemic kidney by maintaining the redox balance and regulating the generation of inflammatory mediator. The outcomes suggest that ubiquinol may be a potential candidate to counteract organ dysfunction in conditions involving IR injury.

背景与目标： : 毒性氧代谢产物的产生，随后是氧化和炎症介导的组织损伤，在缺血和再灌注 (IR) 的发病机理中起着至关重要的作用。泛醇是辅酶Q10的还原形式，因其在生物膜中的有效抗氧化和抗炎特性而被认可。本研究旨在研究泛醇对肾脏IR损伤的可能保护作用。将雄性Wistar大鼠分组为假手术组，泛醇组，IR (45分钟双侧肾缺血，随后24小时再灌注) 和泛醇 + IR (泛醇300 mg/kg，在IR诱导前连续7天口服)。在再灌注结束时评估肾脏形态，功能，氧化应激和炎症标志物。IR引起肾功能不全，如血尿素氮，血浆肌酐显着增加和肌酐清除率降低所示。光镜和电子显微镜检查显示严重的肾小管损伤和线粒体结构异常。IR诱导的肾损伤与丙二醛，一氧化氮，肿瘤坏死因子-α 的显着增加有关，但抗氧化剂硫醇和超氧化物歧化酶的降低有关。泛醇预处理明显减弱了IR引起的所有变化，而在假手术大鼠中没有明显影响。这些发现表明，在IR发生之前补充泛醇可通过维持氧化还原平衡和调节炎症介质的产生来赋予缺血性肾脏功能和形态学保护。结果表明，泛醇可能是在涉及IR损伤的情况下抵消器官功能障碍的潜在候选者。

BACKGROUND & AIMS: :A study is presented of the kinetics and stoichiometry of fast proton translocation associated to aerobic oxidation of components of the mitochondrial respiratory chain. 1. Aerobic oxidation of ubiquinol and b cytochromes is accompanied in EDTA particles, obtained by sonication of beef-heart mitochondria, by synchronous proton uptake. 2. The rapid proton uptake associated to oxidation and b cytochromes is greatly stimulated by valinomycin plus K+, but is unaffected by carbonyl cyanide p-trifluoromethoxyphenylhydrazone. 3. 4 gion H+ are taken up per mol ubiquinol oxidized by oxygen. This H+/2e- ratio, measured in the rapid anaerobic-aerobic transition of the particles is unaffected by carbonyl cyanide p-trifluoromethoxyphenylhydrazone. 4. Intact mitochondria aerobic oxidation of oxygen-terminal electron carriers is accompanied by antimycin-insensitive synchronous proton release, oxidation of ubiquinol and reduction of b cytochromes. The amount of protons released is in excess with respect to the amount of ubiquinol oxidized. 5. It is concluded that electron flow along complex III, from ubiquinol to cytochrome c, is directly coupled to vectorial proton translocation. The present data suggest that there exist(s) between ubiquinol and cytochrome c one (or two) respiratory carrier(s), whose oxido-reduction is directly linked to effective transmembrane proton translocation.

背景与目标： : 提出了与线粒体呼吸链组分的有氧氧化相关的快速质子易位的动力学和化学计量的研究。1.EDTA颗粒中伴随着泛醇和b细胞色素的需氧氧化，EDTA颗粒是通过同步质子吸收牛肉心脏线粒体的超声处理获得的。2.与氧化和b细胞色素相关的快速质子吸收受到缬氨酸霉素加K的极大刺激，但不受羰基氰化物对三氟甲氧基苯基hydr的影响。3.4gion H + 被氧氧化的每摩尔泛醇吸收。在颗粒的快速厌氧-好氧转变中测得的H/2e比不受羰基氰化物对三氟甲氧基苯基hydr的影响。4.完整的线粒体氧末端电子载体的有氧氧化伴随着抗霉素不敏感的同步质子释放，泛醇的氧化和b细胞色素的还原。释放的质子量相对于泛醇氧化的量过量。5.得出的结论是，沿复合物III从泛醇到细胞色素c的电子流直接与矢量质子易位耦合。目前的数据表明，泛醇和细胞色素c之间存在一个 (或两个) 呼吸载体，其氧化还原与有效的跨膜质子易位直接相关。

BACKGROUND & AIMS: :In wild-type yeast cells, steady-state concentrations of subunits of the ubiquinol-cytochrome c reductase complex (complex III) and the levels of their translatable mRNAs change coordinately in response to the need for mitochondrial function. Despite this, re-introduction of the cloned gene for one of the subunits (11 kd) into cells by transformation with a free-replicating plasmid results in the discoordinate synthesis of this subunit only, without effects on either the synthesis or degradation of the other subunits. The overproduced subunit is associated with the mitochondrial fraction, yet does not interfere with mitochondrial function, as judged by the growth of transformed cells on nonfermentable media. Quantitative analysis of both mRNA and protein levels suggests that both translational controls and elevated turnover of excess protein contribute to a partial compensation for the effects of increased gene dosage in transformed cells. These contain approximately 30 copies of the cloned gene and 15-30 times the normal level of its mRNA. Nevertheless, synthesis of the 11-kd protein is only 6- to 8-fold higher than normal, and steady-state levels are increased only 5- to 10-fold. These findings imply that synthesis of the various subunits of complex III is not tightly coupled and that for the 11-kd subunit at least, the level of mRNA is likely to be the most important means of regulating protein level. Fine-tuning may be additionally achieved by control of translation and degradation of excess protein which is not assembled in the complex.

背景与目标： : 在野生型酵母细胞中，泛醇-细胞色素c还原酶复合物 (复合物III) 的亚单位的稳态浓度及其可翻译mrna的水平随线粒体功能的需求而协调变化。尽管如此，通过用自由复制质粒转化将克隆的一个亚基 (11 kd) 的基因重新引入细胞中仅导致该亚基的不配位合成，而对该亚基的合成或降解没有影响其他亚基。根据转化细胞在不可发酵培养基上的生长判断，过量产生的亚基与线粒体部分相关，但不会干扰线粒体功能。mRNA和蛋白质水平的定量分析表明，翻译对照和过量蛋白质的周转率升高均有助于部分补偿转化细胞中基因剂量增加的影响。这些包含大约30个克隆基因拷贝，是其mRNA正常水平的15-30倍。尽管如此，11-kd蛋白的合成仅比正常水平高6至8倍，而稳态水平仅增加5至10倍。这些发现表明，复合物III的各种亚基的合成不是紧密耦合的，并且至少对于11-kd亚基，mRNA的水平可能是调节蛋白质水平的最重要手段。可以通过控制在复合物中未组装的多余蛋白质的翻译和降解来另外实现微调。