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1.
Mg2+对阿霉素引起心肌线粒体F1F0变化的保护 总被引:4,自引:0,他引:4
抗肿瘤药物阿霉素(ADM)对心肌线粒体F1F0-复合体呈现抑制而对F1-ATPase无抑制,这表明ADM可能是通过膜脂起作用的,适当浓度Mg2+能降低ADM对复合体的抑制.经 31P-NMR和标记荧光探针NBD-PE,DPH,MC-540以及内源荧光等的测定,结果表明ADM可能首先通过诱导F1F0膜脂形成非双层脂结构,继而影响了膜脂的堆积程度和流动性,进而引起F1F0-复合体酶蛋白构象的改变,最终导致酶活力的降低.Mg2+则可能由于与ADM竞争与心磷脂的结合,而对ADM引起F1F0的变化产生保护作用. 相似文献
2.
从基因突变的F1-ATP酶(基因突变质粒,α-C193S, γ-S107C,β亚基带有10个组氨酸标记(His-Tag),转入到菌株大肠杆菌JM103)的菌株中筛选出一高表达菌株.该菌株表达的F1-ATP酶经纯化后其水解活性明显高于文献值. 从单分子水平上进行观察,发现在水解ATP过程中,γ亚基上连接的荧光标记蛋白微丝,其旋转速度要比文献中同样条件下快约一倍. 相似文献
3.
猪心线粒体Fo的纯化、重建及其质子转运功能 总被引:1,自引:0,他引:1
比较了猪心线粒体FoF1-ATPase膜部分Fo的四种纯化方法.结果表明,用NaBr从亚线粒体除去FoF1-ATPase的水溶性部分F1-ATPase后,再以CHAPS增溶,并经蔗糖梯度离心,可获得高纯度的Fo.SDS-聚丙烯酰胺凝胶电泳鉴定表明,纯化的Fo含有b、OSCP(寡霉素敏感授予蛋白)、d、a、e、F6、IF1、A6L和c等9种亚基.用去污剂稀释法将纯化的Fo在脂质体上重建后,重建Fo表现较高的被动转运质子活性.这为在体外深入研究Fo的活性、构象与膜脂的关系,以及Fo与F1-ATPase的组装等提供了很好的实验模型. 相似文献
4.
利用ADP和放射性磷直接合成ATP的方法,研究了无机磷(Pi)和叠氮钠对猪心线粒体ATP合成酶(F1FO-ATPase)ATP合成活性的影响.结果发现无机磷除作为合成ATP的底物参与F1FO-ATPase的合成反应外,还对F1FO-ATPase的合成活性呈现抑制作用,在1 mmol/L ADP存在时,随着Pi浓度由0.01~10 mmol/L增加,抑制合成作用越来越强.与叠氮钠在低浓度时(小于1 mmol/L)只抑制ATP水解,不影响ATP合成的观点不同.实验结果显示0.1 mmol/L叠氮钠表观激活F1FO-ATPase的ATP合成活性,且激活程度与反应体系中所加Pi的浓度呈负相关.当固定Pi浓度(0.1 mmol/L)后,随着叠氮钠浓度的增加表观激活程度也在变化,叠氮钠与磷浓度相等时表观激活程度最大,直至叠氮钠浓度接近0.5 mmol/L时,开始呈现表观抑制现象,叠氮钠浓度高于1 mmol/L之后,就出现解偶联现象. 相似文献
5.
线粒体形态和功能的异常与多种疾病的发生密切相关。线粒体通过不断的分裂和融合,维持线粒体网络的动态平衡,该过程称为线粒体动力学,是维持线粒体形态、分布和数量,保证细胞稳态的重要基础。此外,机体还通过线粒体自噬过程降解胞内功能异常的线粒体,维持线粒体稳态。线粒体动力学与线粒体自噬二者之间可相互调控,共同维持线粒体质量平衡。探讨线粒体动力学和线粒体自噬的调控机制对揭示多种疾病发生的分子机制、开发新的靶向线粒体动力学蛋白或线粒体自噬调控蛋白的药物具有重要意义。本文从线粒体动力学与线粒体自噬出发,对线粒体动力学调控机制、线粒体自噬及其发生机制以及二者的相互作用关系、线粒体动力学及线粒体自噬与人类相关疾病等方面作一综述。 相似文献
6.
线粒体F1Fo复合体Fo部分a亚基的色氨酸荧光可被竹红菌乙素(hypocrellin B, HB)猝灭.不同温度下测定Stern-Volmer图的结果显示,猝灭常数(Ksv)随温度的增加而加大,时间衰变荧光的结果显示,荧光寿命随HB浓度的增加而减小,加入不同浓度的HB, F1Fo复合体的吸收峰没有位移.这些实验结果支持动态猝灭机理.HB还具有有效猝灭浓度低,不影响酶的活力;在脂相和水相的分布比率可高达16 560∶1;实验操作简便等优点.因此HB可作为理想的疏水相荧光猝灭剂,研究与膜结合的F1Fo复合体中镶嵌于膜脂内Fo的构象变化. 相似文献
7.
关于线粒体的发育的研究,较多地以动物和酵母为对象,植物较少。而线粒体发育过程中 H~+-ATP 酶的 F_1-ATP 酶变化的研究,目前尚未见报道。本文以豌豆子叶为材料,就线粒体的发育,H~+-ATP 酶活性变化以及这种变化与 F_1-ATP 酶亚基组成的相关性进行了初步研究,其最终目的是探讨线粒体发育过程中内膜的发生及膜蛋白的组装问题。 相似文献
8.
线粒体在细胞的生命活动过程中承担重要作用,线粒体通过自身质量控制维持线粒体健康.线粒体囊泡作为一种新型的线粒体质量控制机制,通过靶向到不同的细胞器,调控线粒体内氧化/受损蛋白的降解;激活免疫系统,发挥抗原呈递和杀灭细菌的功能,从而维持线粒体以及细胞的稳态平衡.本文就线粒体囊泡的调控机制以及生物学功能的研究进展进行综述. 相似文献
9.
三氧化二砷下调MG-63骨肉瘤细胞IEX-1基因表达的转录调控机制研究 总被引:1,自引:0,他引:1
三氧化二砷(arsenic trioxide, As2O3)是中国传统中药砒霜的主要有效成分,最早应用于血液系统肿瘤的治疗,随后研究表明其对实体瘤也具有抑制细胞增殖并诱导凋亡的作用.早期研究发现,1.0 μmol/L的As2O3可以体外诱导骨肉瘤细胞系MG-63细胞凋亡,进一步的cDNA芯片分析、RT-PCR、RNA印迹证实细胞凋亡与As2O3干预后IEX-1基因表达下调有关.IEX-1为早期诱导应答基因,调节细胞生长和凋亡.通过荧光素酶分析,EMSA、蛋白质印迹等实验,发现As2O3干预骨肉瘤细胞系MG-63后能诱导p53蛋白表达上调,增加的p53蛋白通过与IEX-1的启动子结合,转录抑制IEX-1的转录,导致IEX-1基因表达下调.进一步证实了IEX-1与骨肉瘤的重要关系,同时也阐明As2O3诱导IEX-1基因表达下调的转录调控机制. 相似文献
10.
测定线粒体细胞色素c,c1,b,aa3含量的简单方法 总被引:2,自引:0,他引:2
线粒体是细胞中的重要细胞器,能量代谢的主要场所.在呼吸链中,细胞色素c,c_1,b,aa_3起着电子传递中间体的作用,其任何一种含量的减少或缺失将影响细胞的呼吸功能.由于细胞色素是一类带有卟啉环的蛋白质,在可见光区域有明显的吸收,可以利用这一性质进行比色定量。J.N.Williams首先建立了测定线粒体还原-氧化差光谱计算细胞色素含量的方 相似文献
11.
Ferruccio Guerrieri Martin Kalous Edmondo Adorisio Nicola Turturro Zdenek Drahota Palmiro Cantatore Giuseppe Santoro 《Journal of bioenergetics and biomembranes》1998,30(3):269-276
In liver mitochondria isolated from hypothyroid rats, the rate of ATP synthesis is lower than in mitochondria from normal rats. Oligomycin-sensitive ATP hydrolase activity and passive proton permeability were significantly lower in submitochondrial particles from hypothyroid rats compared to those isolated from normal rats. In mitochondria from hypothyroid rats, the changes in catalytic activities of F0F1-ATP synthase are accompanied by a decrease in the amount of immunodetected -F1, F01-PVP, and OSCP subunits of the complex. Northern blot hybridization shows a decrease in the relative cytosolic content of mRNA for -F1 subunit in liver of hypothyroid rats. Administration of 3,5,3-triodo-L-thyronine to the hypothyroid rats tends to remedy the functional and structural defects of F0F1-ATP synthase observed in the hypothyroid rats. The results obtained indicate that hypothyroidism leads to a decreased expression of F0F1-ATP synthase complex in liver mitochondria and this contributes to the decrease of the efficiency of oxidative phosphorylation. 相似文献
12.
Sergio Papa Fzaneo Zanotti Antonio Gaballo 《Journal of bioenergetics and biomembranes》2000,32(4):401-411
The structural and functional connection between the peripheral catalytic F1 sector and theproton-translocating membrane sector F0 of the mitochondrial ATP synthase is reviewed. Theobservations examined show that the N-terminus of subunit , the carboxy-terminal and centralregion of F0I-PVP(b), OSCP, and part of subunit d constitute a continuous structure, the lateralstalk, which connects the peripheries of F1 to F0 and surrounds the central element of thestalk, constituted by subunits and . The ATPase inhibitor protein (IF1) binds at one sideof the F1F0 connection. The carboxy-terminal segment of IF1 apparently binds to OSCP. The42L-58K segment of IF1, which is per se the most active domain of the protein, binds at thesurface of one of the three / pairs of F1, thus preventing the cyclic interconversion of thecatalytic sites required for ATP hydrolysis. 相似文献
13.
Marcus V.J. Rocha Melissa S. Caetano Elaine F.F. da Cunha 《Journal of biomolecular structure & dynamics》2013,31(10):1175-1181
Organotin compounds are the active components of some fungicides, which are potential inhibitors of the F1F0-ATP synthase. The studies about the reaction mechanism might indicate a pathway to understand how these compounds work in biological systems, however, has not been clarified so far. In this line, molecular modeling studies and density functional theory calculations were performed in order to understand the molecular behavior of those compounds when they interact with the active site of the enzyme. Our findings indicate that a strong interaction with His132 can favor a chemical reaction with organotin compounds due to π–π stacking interactions with aromatic rings of organotin compounds. Furthermore, dependence on molecule size is related to possibility of reaction with the amino acid residue His132. Thus, it can also be noticed, for organotin compounds, that substituents with four carbons work by blocking the subunit a, in view of the high energy transition found characterized by steric hindrance. 相似文献
14.
Mitochondrial ATP synthase (F1F0-ATPase) is regulated by an intrinsic ATPase inhibitor protein. In this study, we overexpressed and purified human and bovine ATPase inhibitors and their properties were compared with those of a yeast inhibitor. The human and bovine inhibitors inhibited bovine ATPase in a similar way. The yeast inhibitor also inhibited bovine F1F0-ATPase, although the activity was about three times lower than the mammalian inhibitors. All three inhibitors inhibited yeast F1F0-ATPase in a similar way. The activities of all inhibitors decreased at higher pH, but the magnitude of the decrease was different for each combination of inhibitor and ATPase. The results obtained in this study show that the inhibitory mechanism of the inhibitors was basically shared in yeast and mammals, but that mammalian inhibitors require unique residues, which are lacking in the yeast inhibitor, for their maximum inhibitory activity. Common inhibitory sites of mammalian and yeast inhibitors are suggested. 相似文献
15.
Bravo C Minauro-Sanmiguel F Morales-Ríos E Rodríguez-Zavala JS García JJ 《Journal of bioenergetics and biomembranes》2004,36(3):257-264
According to functional studies, the higher IF(1) content reported in mitochondria of cancerous cells is supposed to induce a higher association with the F(1)F(0) complex than in normal cells and therefore a better inhibition of its ATPase activity. The first structural evidence supporting this prediction is here presented. Densitometric analyses of Western blotting experiments indicated a 2-fold increase in IF(1) content of AS-30D submitochondrial particles compared to normal rat liver controls. The ratio of IF(1)/F(1) alpha subunit increased similarly as judged by Westernblot analyses. This IF(1) overexpression correlated with a slower rate of IF(1) release (F(1)F(0)-ATPase activation) from the F(1)F(0) complex in AS-30D than in normal rat liver submitochondrial particles. The IF(1)-IF(1), gamma-IF(1), and alpha-IF(1) cross-linkages previously formed with dithiobis(succinimidylpropionate) in bovine F(1)F(0)I and IF(1) complexes were reproduced in the F(1)F(0)I-ATP synthase of hepatoma AS-30D cells. However, a much lower yield of IF(1) cross-linkages was found in normal rat liver particles which made them almost undetectable in SMP as well as in the immunoprecipitated F(1)F(0)I complex. Modeling in vivo IF(1) overexpression of cancerous cells by in vitro reconstitution of excess recombinant IF(1) with rat liver submitochondrial particles devoid of IF(1) reproduced the same IF(1) cross-linkages observed in AS-30D particles. 相似文献
16.
The inhibitor protein IF1 is a basic protein of 84 residues which inhibits the ATPase activity of the mitochondrial FoF1-ATP synthase complex without having any effect on ATP synthesis. Results of cross-linking and limited proteolysis experiments are presented showing that in the intact FoF1 complex "in situ," in the inner membrane of bovine heart mitochondria, the central segment of IF1 (residues 42-58) binds to the alpha and beta subunits of F1 in a pH dependent process, and inhibits the ATPase activity. The C-terminal region of IF1 binds, simultaneously, to the OSCP subunit of Fo in a pH-independent process. This binding keeps IF1 anchored to the complex, both under inhibitory conditions, at acidic pH, and noninhibitory conditions at alkaline pH. 相似文献
17.
18.
Karina Wagner Peter Rehling Luiza K. Sanjuán Szklarz Rebecca D. Taylor Martin van der Laan 《Journal of molecular biology》2009,392(4):855-257
Mitochondrial F1Fo-ATP synthase catalyzes the formation of ATP from ADP and inorganic phosphate. The enzyme is found in monomeric, dimeric and higher oligomeric forms in the inner mitochondrial membrane. Dimerization of ATP synthase complexes is a prerequisite for the generation of larger oligomers that promote membrane bending and formation of tubular cristae membranes. Two small proteins of the membrane-embedded Fo-domain, subunit e (Su e; Atp21) and Su g (Atp20), were identified as dimer-specific subunits of yeast ATP synthase and shown to be required for stabilization of the dimers. We have identified two distinct monomeric forms of yeast ATP synthase. Su e and Su g are present not only in the dimer but also in one of the monomeric forms. We demonstrate that Su e and Su g sequentially assemble with monomeric ATP synthase to form a dimerization-competent primed monomer. We conclude that association of Su e and Su g with monomeric F1Fo-ATP synthase represents an initial step of oligomer formation. 相似文献
19.
Hase Y Tatsuno M Nishi T Kataoka K Kabe Y Yamaguchi Y Ozawa N Natori M Handa H Watanabe H 《Biochemical and biophysical research communications》2008,366(1):66-72
Atrazine is a widely used triazine herbicide. Although controversy still exists, a number of recent studies have described its adverse effects on various animals including humans. Of particular interest is its effects on reproductive capacity. In this study, we investigated the mechanisms underlying the adverse effects of atrazine, with a focus on its effects on sperm. Here we show evidence that mitochondrial F1F0-ATP synthase is a molecular target of atrazine. A series of experiments with sperm and isolated mitochondria suggest that atrazine inhibits mitochondrial function through F1F0-ATP synthase. Moreover, affinity purification using atrazine as a ligand demonstrates that F1F0-ATP synthase is a major atrazine-binding protein in cells. The inhibitory activity against mitochondria and F1F0-ATP synthase is not limited to atrazine but is likely to be applicable to other triazine-based compounds. Thus, our findings may have wide relevance to pharmacology and toxicology. 相似文献
20.
Beef-heart mitochondrial F1F0-ATP synthase contained six molecules of bound inorganic phosphate (Pi). This phosphate exchanged completely with exogenous 32Pi when the enzyme was exposed to 30% (v/v) dimethyl sulfoxide (DMSO) and then returned to a DMSO-free buffer (Beharry and Bragg 2001). Only two molecules were replaced by 32Pi when the enzyme was not pretreated with DMSO. These two molecules of 32Pi were not displaced from the enzyme by the treatment with 1 mM ATP. Similarly, two molecules of bound 32Pi remained on the DMSO-pretreated enzyme following addition of ATP, that is, four molecules of 32Pi were displaced by ATP. The ATP-resistant 32Pi was removed from the enzyme by pyrophosphate. It is proposed that these molecules of 32Pi are bound at an unfilled adenine nucleotide-binding noncatalytic site on the enzyme. Brief exposure of the enzyme loaded with two molecules of 32Pi to DMSO, followed by removal of the DMSO, resulted in the loss of the bound 32Pi and in the formation of two molecules of bound ATP from exogenous ADP. A third catalytic site on the enzyme was occupied by ATP, which could undergo a Pi ATP exchange reaction with bound Pi The presence of two catalytic sites containing bound Pi is consistent with the X-ray crystallographic structure of F1 (Bianchet, et al., 1998). Thus, five of the six molecules of bound Pi were accounted for. Three molecules of bound Pi were at catalytic sites and participated in ATP synthesis or Pi ATP exchange. Two other molecules of bound Pi were present at a noncatalytic adenine nucleotide-binding site. The location and role of the remaining molecule of bound Pi remains to be established. We were unable to demonstrate, using chemical modification of sulfhydryl groups by iodoacetic acid, any gross difference in the conformation of F1F0 in DMSO-containing compared with DMSO-free buffers. 相似文献