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SLIP AND LEAK IN MITOCHONDRIAL OXIDATIVE-PHOSPHORYLATION

BIOCHIMICA ET BIOPHYSICA ACTA 1989年第2期977卷 123-141页

作者： MURPHY, MP COLUMBIA UNIV COLL PHYS & SURG DEPT MED NEW YORK NY 10032 USA

During oxidative phosphorylation by mammalian mitochondria part of the free energy stored in reduced substrates is dissipated and energy is released as heat. Here I review the mechanisms and the physiological signific... 详细信息

关键词： Oxidative phosphorylation Slip Leak Membrane permeability Stoichiometry change BSA bovine serum albumin L H effective proton conductance of the mitochondrial inner membrane DCCD N,N ′-dicyclohexylcarbodiimide E h redox potential at a defined pH with respect to a standard hydrogen electrode ΔE h difference in redox potential between two carriers of reducing equivalents at a defined pH ffA free fatty acid ΔG p phosphorylation potential, which is defined as ΔG p = ΔG 0 ′+ RT ln[ATP]/[ADP][P i ] H + /ATP number of protons taken up from the external medium by the f 0 f 1 -ATPase per ATP synthesized H + /O number of protons released to the external phase per pair of electrons passed to oxygen J H + the net leak or current of protons through the mitochondrial inner membrane Δp protonmotive force across the mitochondrial inner membrane which is defined (in mV at 37°C) as Δp=Δψ −61.5 Δ pH Δ pH proton concentration gradient across the mitochondrial inner membrane P/O number of ADP molecules phosphorylated per pair of electrons passed to oxygen state 3 state of respiration when respiratory substrate and excess ADP are present state 4 state of controlled respiration when respiratory substrate is present and added ADP has been phosphorylated T 3 , L -3, 3′, 5-triiodothyronine T 4 L -3,3′,5,5′-triiodothyronine TMPD N,N,N′,N′ -tetramethyl- p -phenylenediamine TPMP methyltriphenylphosphonium cation Δψ electrical potential difference across the mitochondrial inner membrane

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TRANSMEMBRANE SIGNALING - TUMOR PROMOTER DISTRIBUTION

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BIOCHIMICA ET BIOPHYSICA ACTA 1989年第2期982卷 237-244页

作者： fISHER, KA YANAGIMOTO, KC UNIV CALIF SAN FRANCISCO DEPT BIOCHEM & BIOPHYS SAN FRANCISCO CA 94143 USA

Diacylglycerol plays a critical role in transmembrane signaling by activating protein kinase C (PKC). The tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA) mimics that action, and in the human erythrocyte, TPA-activated PKC phosphorylates membrane proteins. Although molecular aspects of this process have been investigated, details of the interaction of TPA with plasma membranes remain elusive. Because TPA is hydrophobic, it has been assumed that it associates with the lipid bilayer. However, there is no direct evidence for its transbilayer distribution. Because knowledge of its location would limit molecular models proposed to explain its mode of action, we have used membrane-splitting techniques, based on freeze-fracture of planar cell monolayers, to quantify transmembrane partitioning of [3H]TPA. Under conditions where PKC-mediated phosphorylation was stimulated by [3H]TPA and where more than 90% of the [3H]TPA was associated with the human red cell plasma membrane, two-thirds of the TPA partitioned with the cytoplasmic leaflet after bilayer splitting. This represents the first direct topographic localization of TPA in a biological membrane and supports the hypothesis that the mechanism of TPA activation requires its association with the cytoplasmic leaflet of the bilayer.

关键词： Membrane splitting Protein kinase C Red blood cell Tumor promoter Diacylglycerol Phorbol ester 12- O -Tetradecanoylphorbol 13-acetate A absorbance DAG diacylglycerol DBLAMS double-labeled membrane splitting Me 2 SO dimethylsulfoxide f fluorescence fITC-Con A fluorescein isothiocyanate conjugated concanavalin A HBS Hepes-buffered saline LSC liquid-scintillation counting PAGE polyacrylamide gel electrophoresis PKC protein kinase C PLG polylysine-treated glass RBC human red blood cell SDS sodium dodecyl sulfate SMM single membrane monolayer TLC thin-layer chromatography TPA 12- O -tetradecanoylphorbol 13-acetate

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CYCLOSPORINE A INHIBITS ENDOTHELIUM-DEPENDENT VASODILATATION AND VASCULAR PROSTACYCLIN PRODUCTION

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EUROPEAN JOURNAL Of PHARMACOLOGY 1989年第1期165卷 165-169页

作者： BOSSALLER, C fORSTERMANN, U HERTEL, R OLBRICHT, C RESCHKE, V fLECK, E GERMAN HEART INST BERLIN DEPT CARDIOL AUGUSTENBURGER PL 1 D-1000 BERLIN 65 FED REP GER HANNOVER MED SCH DEPT CLIN PHARMACOL D-3000 HANNOVER 61 FED REP GER HANNOVER MED SCH DEPT NEPHROL D-3000 HANNOVER 6 FED REP GER FRAUNHOFER INST D-3000 HANNOVER 61 FED REP GER

Aortic rings dissected from rats treated with cyclosporin A (30 mg/kg per day for five days) showed reduced relaxation induced by the endothelium-dependent vasodilator acetylcholine, but unchanged responses induced by glyceryl trinitrate. After eight weeks of cyclosporin A treatment, the relaxation induced by both acetylcholine and glyceryl trinitrate was inhibited. In addition, phenylephrine-induced contractions were slightly enhanced and vascular prostacyclin production was reduced by more than 80%. These effects may participate in the hypertensive and thrombo-embolic complications associated with the clinical use of cyclosporin A.

关键词： Aorta Acetylcholine Endothelium Glyceryl trinitrate 6-keto-PGf 1α f 1α (Radioimmunoassay, Rat)

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REGENERATION IN CHICKPEA (CICER-ARIETINUM-L) THROUGH SOMATIC EMBRYOGENESIS

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JOURNAL Of PLANT PHYSIOLOGY 1989年第5期134卷 637-638页

作者： RAO, BG CHOPRA, VL Biotechnology Centre Indian Agricultural Research Institute New Delhi-110012 India

Somatic embryos were obtained from leaflet-derived callus of Cicer arietinum L. for obtaining a high frequency of embryogenic cultures, growth regulator supplement and incubation conditions during the callusing phase are critical. MS medium supplemented with 0.5 mg/l each of 2,4-D and BAP and dark incubation was found best for producing embryogenic callus. High frequency of embryogenesis was obtained after transferring the callus to MS medium supplemented with IAA and BAP.

关键词： Cicer arietinum L Biotechnology Somatic embryogenesis Tissue Culture BAP benzyl amino purine 2,4-D 2-4-dichlorophenoxy acetic acid f 1 first filial generation f 2 second filial generation IAA indole acetic acid Lo.s. level of significance MS Murashige and Skoog (1962)

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ACTIN POLYMERIZATION AS AN ESSENTIAL PROCESS IN LIGHT-CONTROLLED AND DARK-CONTROLLED CHLOROPLAST ANCHORAGE

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BIOCHEMIE UND PHYSIOLOGIE DER PfLANZEN 1989年第5-6期185卷 337-342页

作者： SCHONBOHM, E MEYERWEGENER, J Photobiology Department of Botany FB 17 Philipps-University of Marburg FRG

The effect of the actin-inhibitor cytochalasin B on low fluence-rate chloroplast movements and on Pfr-mediated increase of chloroplast anchorage to the cytoplasmic parietal coating of a Mougeotia cell was investigated. We found that cytochalasin B decreases chloroplast anchorage in far-red irradiated and also in dark-sensitized cells. The results show that actin polymerization is not only involved in light-oriented chloroplast movements but also in the process of chloroplast anchorage to the cytoplasmic parietal coating of the longitudinal cell walls. The results provide a further strong argument for the assumption that both responses, the Pfr-controlled chloroplast movement as well as the Pfr-mediated increase of chloroplast anchorage are realized via similar transduction chains.

关键词： actin chloroplast movements chloroplast anchorage cytochalasin B phytochrome Mougeotia spec ATP adenosine-triphosphate CB cytochalasin B DMSO dimethylsulfoxide f actin filaments G-actin actin monomer MXS nutrient medium after STABENAU (1978) PCMB pchloromercuribenzoate P fr phytochrome in its physiological active, i.e. far-red absorbing form salyrgane o-{[3(hydroxymercuri)-2-methoxypropyl] carbamoyl} phenoxyacetic acid: Na-salt SLM high fluence rate movement WLM low fluence rate movement

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MITOCHONDRIAL PROTEIN IMPORT

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BIOCHIMICA ET BIOPHYSICA ACTA 1989年第1期988卷 1-45页

作者： HARTL, fU PfANNER, N NICHOLSON, DW NEUPERT, W Institut für Physiologische Chemie der Universität München München F.R.G.

Most mitochondrial proteins are synthesized as precursor proteins on cytosolic polysomes and are subsequently imported into mitochondria. Many precursors carry amino-terminal presequences which contain information for their targeting to mitochondria. In several cases, targeting and sorting information is also contained in non-amino-terminal portions of the precursor protein. Nucleoside triphosphates are required to keep precursors in an import-competent (unfolded) conformation. The precursors bind to specific receptor proteins on the mitochondrial surface and interact with a general insertion protein (GIP) in the outer membrane. The initial interaction of the precursor with the inner membrane requires the mitochondrial membrane potential (delta psi) and occurs at contact sites between outer and inner membranes. Completion of translocation into the inner membrane or matrix is independent of delta psi. The presequences are cleaved off by the processing peptidase in the mitochondrial matrix. In several cases, a second proteolytic processing event is performed in either the matrix or in the intermembrane space. Other modifications can occur such as the addition of prosthetic groups (e.g., heme or fe/S clusters). Some precursors of proteins of the intermembrane space or the outer surface of the inner membrane are retranslocated from the matrix space across the inner membrane to their functional destination ('conservative sorting'). finally, many proteins are assembled in multi-subunit complexes. Exceptions to this general import pathway are known. Precursors of outer membrane proteins are transported directly into the outer membrane in a receptor-dependent manner. The precursor of cytochrome c is directly translocated across the outer membrane and thereby reaches the intermembrane space. In addition to the general sequence of events which occurs during mitochondrial protein import, current research focuses on the molecules themselves that are involved in these processes.

关键词： ADH alcohol dehydrogenase (EC 1.1.1.1) CCCP carbonylcyanide- m -chlorophenylhydrazone Cox cytochrome oxidase DHfR dihydrofolate reductase ΔΨ membrane potantial across the inner mitochondrial membrane ER endoplasmic reticulum fCCP carbonylcyanide-4-trifluoromethoxyphenylhydrazone f 1 β subunit 2 (subunit β) of f 1 ATPase GIP general insertion protein MPP matrix processing peptidase NTPs nucleoside triphosphates OTC ornithine transcarbamoylase PEP processing enhancing protein, hsp, heat-shock protein

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“安胎健母宝”对妊娠子宫的营养作用以及与PGf2a关系

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江西中医学院学报 1989年第2期2卷 40-42页

作者：周楚华王敏璋杨明志

安胎健母宝是根据寿胎丸处方组成研制的,本文在假孕的基础上观察安胎健母宝对子宫营养功能的影响以及与前列腺素的关系,发现安胎健母宝能促进脑垂体一卵巢黄体功能,增进子宫组织中蛋白质、糖的合成、增强子宫中碱性磷酸酶的活性,从而促... 详细信息

安胎健母宝是根据寿胎丸处方组成研制的,本文在假孕的基础上观察安胎健母宝对子宫营养功能的影响以及与前列腺素的关系,发现安胎健母宝能促进脑垂体一卵巢黄体功能,增进子宫组织中蛋白质、糖的合成、增强子宫中碱性磷酸酶的活性,从而促进子宫发育,提供能量,有利于安胎健母作用。另一方面前列腺素(PGf2a)具有溶黄体功能,增强子宫运动,终止妊娠。PGf2a 这种作用能被安胎健母宝阻断,表明安胎健母宝可能通过抗 PGf2a 作用而起安胎健母作用。

关键词：子宫/药物作用前列腺素 f 类合成/拮抗剂和抑制剂安胎 @安胎健母宝/药放学

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L-fuzzy几乎及半几乎连续序同态

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四川师范大学学报（自然科学版） 1989年第4期12卷 21-28页

作者：黄蕴魁四川师范大学自贡师专

本文在L-fuzzy 连续序同态(王国俊,1989)的基础上,讨论和研究了L-fuzzy

关键词： Lf 拓扑空间 f 格上的序同态 Lf 几乎连续序同态

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THE PROTON PORE Of THE f0f1-ATPASE Of ESCHERICHIA-COLI - SER-206 IS NOT REQUIRED fOR PROTON TRANSLOCATION

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BIOCHIMICA ET BIOPHYSICA ACTA 1988年第1期936卷 74-80页

作者： HOWITT, SM GIBSON, f COX, GB Division of Biochemical Sciences John Curtin School of Medical Research Australian National University Canberra Australia

A series of experiments was carried out to investigate the role of some polar amino acids in the a-subunit of the ATP synthase of Escherichia coli. Site-directed mutagenesis resulted in the amino acid substitutions Ser-199 .fwdarw. Ala, Ser-202 .fwdarw. Ala, Ser-206 .fwdarw. Ala, Arg-61 .fwdarw. Gln or Asp-44 .fwdarw. Asn. None of these amino acid substitutions affected the ability of the cells to carry out oxidative phosphorylation. It was concluded therefore that the effect of the subtitution of leucine for Ser-206 reported previously (Cain, B.D. and Simoni, R.D. (1986) J. Biol. Chem. 261, 10043-10050) was due to the presence of the leucine rather than the absence of serine. Even though cells carrying the Asp-44 .fwdarw. Asn substitution were able to carry out oxidative phosphorylation, membranes from such cells remained proton-impermeable after removal of the f1-ATPase. It appears likely that the proton pore of the f0 of the ATP synthase of E. coli consists of four amino acids, namely Arg-219, Glu-210 and His-245 of the a-subunit and Asp-61 of the c-subunit.

关键词： ATPase, f 0 f 1 Proton channel Site directed mutagenesis ( E. coli ) DCCD dicyclohexylcarbodiimide

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GREEN ALGAL CYTOCHROME B6-f-COMPLEXES - ISOLATION AND CHARACTERIZATION fROM DUNALIELLA-SALINE, CHLAMYDOMONAS-REINHARDTII AND SCENEDESMUS-OBLIQUUS

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BIOCHIMICA ET BIOPHYSICA ACTA 1988年第2期935卷 115-122页

作者： WYNN, RM BERTSCH, J BRUCE, BD MALKIN, R UNIV CALIF BERKELEY DIV MOLEC PLANT BIOL 313 HILGARD HALL BERKELEY CA 94720 USA

Cytochrome b6-f complexes have been isolated from Chlamydomonas reinhardtii, Dunaliella salina, and Scenesdesmus obliquus. Each complex is essentially free of chlorophyll and carotenoids and contains cytochrome b6 and cytochrome f hemes in a 2:1 molar ratio. C. reinhardtii and S. obliquus complexes contain the Rieske iron-sulfar protein (present in approx. 1:1 molar ratio to cytochrome f) and each catalyzes a DBMIB- and DNP-INT-sensitive electron transfer from duroquinol to spinach plastocyanin. Immunological assays using antibodies to the peptides from the spinach cytochrome complex show varying cross-reactivity patterns except for the complete absence of binding to the Rieske protein in any of the three complexes, suggesting little structural similarity between the Rieske proteins of algae with those from higher plants. One complex (D. salina) has been uniformly labeled by growth in NaH14CO3 to determine stoichiometries of constituent polypeptide subunits. Results from these studies indicate that all functionally active cytochrome b6-f complexes contain four subunits which occur in equimolar amounts.

关键词： Cytochrome f Cytochrome b 6 Rieske fe-S protein Plastoquinone Electron transfer DBMIB 2,5-dibromo-3-methyl-6-isopropyl-1,4-benzoquinone DNP-INT 2-iodo-2′,4′,4′-trinitro-3-methyl-6-isopropyl diphenyl ether EPR electron paramagnetic resonance Rfe-S Rieske iron-sulfur protein SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis

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