检索结果-内蒙古大学图书馆

ISOLATION AND CHARACTERIZATION Of MONOCLONAL-ANTIBODIES AGAINST HYDROPHOBIC MEMBRANE SUBUNIT-9 Of THE YEAST MITOCHONDRIAL H+-ATPASE

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1988年第1期933卷 223-228页

作者： JEANfRANCOIS, MJB HERTZOG, PJ MARZUKI, S MONASH UNIV DEPT BIOCHEM CLAYTON VIC 3168 AUSTRALIA MONASH UNIV CTR MOLEC BIOL & MED CLAYTON VIC 3168 AUSTRALIA

five stable lines of myeloma-spleen cell hybrids, producing antibodies against the proteolipid subunit 9 of the yeast mitochondrial H+-ATPase f0-sector, have been isolated by immunizing mice with a proteolipid preparation in the presence of sodium dodecyl sulphate. One of these monoclonal antibodies also reacted with subunit 8 of the enzyme complex indicating a shared epitope. The antibodies did not react with the holo-H+-ATPase, suggesting that their epitopes are shielded by other subunits of the enzyme complex.

关键词： Monoclonal antibody ATPase, H + ATP synthetase Mitochondrial ATPase f 0 -sector (Yeast)

来源：评论

学校读者我要写书评

暂无评论

INTERACTION BETWEEN fENOTEROL, IPRATROPIUM, AND ACETYLCHOLINE ON HUMAN ISOLATED BRONCHUS

引用

JOURNAL Of ALLERGY AND CLINICAL IMMUNOLOGY 1988年第1期82卷 40-46页

作者： ADVENIER, C NALINE, E MATRAN, R TOTY, L BAKDACH, H LAB PHARMACOL PARIS FRANCE CTR CHIRURG VAL OR ST CLOUD FRANCE HOP COCHIN EXPLORAT FONCTIONNELLES RESPIRATOIRES LAB F-75674 PARIS 14 FRANCE CTR MED CHIRURG FOCH F-92151 SURESNES FRANCE

functional antagonism between fenoterol (f) and acetylcholine (ACh) and interaction between f and ipratropium (Ipr) on ACh-induced contraction were evaluated on isolated human bronchi. In the presence of increasing concentrations of ACh (2 .times. 10-4 and2 .times. 10-3 mol/L), dose-response curves of the relaxant effect of f were shifted to the right (0.45 and 0.92 log units), and the maximal effect of f, expressed as a percentage of the effect of theophylline, 3 .times. 10-3 mol/L, was reduced from control values of 92.1 .+-. 4% to 70.8 .+-. 7.0%, and to 67.2 .+-. 7.1%, according to the functional antagonism. In the presence of Ipr, 10-9 and 10-8 mol/L, the functional antagonism between ACh and f was partially reversed. Concentration response-curves to f versus ACh, 2 .times. 10-3 mol/L, were shifted to the left, and although the -log molar concentration producing 50% of maximal effect was not significantly modified, the maximal effect of f was significantly increased in the presence of Ipr, 10-8 mol/L. It is concluded that the effect of combined f and Ipr on the isolated human bronchus contracted with ACh appears to be of the additive type.

关键词： ACh Acetylcholine Ipr Ipratropium f fenoterol EC 50 Concentration producing 50% of maximal effect K D Dissociation constant pD 2 −Log molar EC 50

来源：评论

学校读者我要写书评

暂无评论

THE MODIfICATION Of CHLOROPHYLL fLUORESCENCE Of CHLAMYDOMONAS-REINHARDTII BY PHOTOINHIBITION AND CHLORAMPHENICOL ADDITION SUGGESTS A fORM Of PHOTOSYSTEM-II LESS SUSCEPTIBLE TO DEGRADATION

引用

fEBS LETTERS 1988年第1期236卷 226-230页

作者： BRIANTAIS, JM CORNIC, G HODGES, M Institut de Physiologie Végétale 91198 Gif-sur-Yvette Cedex France

The effect of photoinhibition and chloramphenicol addition on room-temperature chlorophyll fluorescence induction parameters exhibited by Chlamydomonas reinhardtii has been studied. The observed changes induced by these different treatments suggest the presence of a photosystem II (PS II) reaction centre having an abnormal turnover rate and which gives rise to the fast initital variable fluorescence rise ( f i − f o ) in the absence of DCMU. It is proposed that a pool of PS II with a modified D 1 protein exists which is less susceptible to degradation. furthermore, it is shown that the fluorescence quenching associated with photoinhibition is not directly linked to PS II reaction centre degradation.

关键词： Chlorophyll fluorescence induction Chloramphenicol Photoinhibition ( Chlamydomonas ) CAP, chloramphenicol PS, photosystem Chl, chlorophyll f o initial Chl fluorescence f i , intermediate Chl fluorescence f m , maximal Chl fluorescence (+ DCMU) f v , f m − f o . Q A , primary quinonic acceptor of PS II Q B , secondary quinonic acceptor of PS II PfD, photon flux density

来源：评论

学校读者我要写书评

暂无评论

NON-UNIfORM ERROR-BOUNDS fOR ASYMPTOTIC EXPANSIONS Of SCALE MIXTURES Of DISTRIBUTIONS

引用

JOURNAL Of MULTIVARIATE ANALYSIS 1988年第1期27卷 194-205页

作者： fUJIKOSHI, Y Hiroshima University Hiroshima Japan

Let X = σZ be the scale mixture of Z with the scale factor σ > 0. We consider two type expansions G δ , k ( x ) and Φ δ , k ( x ) as the approximations to the distribution function f ( x ) of X . In this paper we derive non-uniform error bounds in approximating f ( x ) by the asymptotic expansions G δ , k ( x ) and Φ δ , k ( x ). The non-uniform bounds are improvements on the uniform bounds in the tail part of the distribution. The results are applied to the asymptotic expansions of t - and f -distributions.

关键词： 62H20 60H05 non-uniform error bounds asymptotic expansion distribution function scale mixture t - and f -distributions

来源：评论

学校读者我要写书评

暂无评论

PURIfICATION AND CHARACTERIZATION Of AN IRON STRESS-INDUCED CHLOROPHYLL-PROTEIN fROM THE CYANOBACTERIUM ANACYSTIS-NIDULANS R2

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1988年第2期935卷 141-151页

作者： RIETHMAN, HC SHERMAN, LA UNIV MISSOURI DIV BIOL SCI TUCKER HALL COLUMBIA MO 65211 USA

An Anacystis nidulans R2 chlorophyll-protein associated with Photosystem II in iron-stressed cells (Pakrasi, H.B., Riethmann, H.C. and Sherman, L.A. (1985) Proc. Natl. Acad. Sci. USA 6903-6907) has been biochemically purified and characterized. Anion exchange chromatography of dodecyl-.beta.-D-maltoside-solubilized membranes from iron-deficient cells was used to recover this chlorophyll-protein (temed CPVI-4) in high yield and in a relatively native state. CPVI-4 has a room temperature absorption maximum at 671 nm, a 77 K chlorophyll fluorescence peak at 681 nm, and contains polypeptides of 36, 34 and 12 kDa. The 36 and 34 kDa polypptides are associated with chlorophyll on mildly denaturing acrylamide gels of purified CPVI-4, although only the 34 kDa protein is immunoreactive with antisera elicited against the gel-purified chlorophyll-protein. Immunoblotting experiments with dodecyl-.beta.-maltoside-solubilized membrane fractions and purified CPVI-4 indicate that CPVI-4 does not contain previously identified Photosystem II core proteins. CPVI-4 likely functions as a light-harvesting antenna complex in iron-starved cells (where phycobilisomes are absent or diminished) and, in addition, may contribute chlorophyll to the reaction center complexes during their assembly in the early stages of recovery from iron stress.

关键词： Iron stress Chlorophyll-protein complex Light harvesting Cyanobacterium ( A. nidulans R2) Chl chlorophyll CP chlorophyll-protein complex Dβ d -maltoside dodecyl-β- d -maltoside f max maximal fluorescence f o original fluorescence f v variable fluorescence LHC light-harvesting chlorophyll-protein PS II Photosystem II PS I Photosystem I

来源：评论

学校读者我要写书评

暂无评论

SOLUBILIZATION AND KINETIC CHARACTERIZATION Of MITOCHONDRIAL ADENOSINE-TRIPHOSPHATASE fROM LEISHMANIA-DONOVANI PROMASTIGOTES

引用

MOLECULAR AND BIOCHEMICAL PARASITOLOGY 1988年第2-3期29卷 153-158页

作者： RASSAM, MBAK ROBERT, ZJ Department of Chemistry College of Sciences University of Baghdad Jadyria Baghdad Iraq

Oligomycin-sensitive particulate ATPase (MB ATPase) from L. donovani promastigotes was solubilized by chloroform treatment. Polyacrylamide gel electrophoresis revealed several protein bands, with the major one possessing ATPase activity. The solubilized enzyme had Mg 2+ -ATPase and Ca 2− -ATPase but no K + -dependent alkaline phosphatase activity. The Mg 2+ -ATPase activity was stimulated by monovalent cations and was not sensitive to oligomycin. Hence it is referred to as f 1 ATPase. It had optimum activity at pH 7.6 and 30°C. The Arrhenius plot for MB ATPase was biphasic with activation energies ( E a ) of 16.2 and 3.4 kcal mol −1 , while f 1 ATPase exhibited a linear plot with E a = 10.1 kcal mol −1 . Lineweaver-Burk plots were biphasic with K m values of 0.17 and 1.25 mM for MB ATPase and 0.18 and 1.33 mM for f 1 ATPase. The enzyme could be preserved at −15°C in Tris-SO 4 2− -EDTA-ATP-glycerol ( t 1 2 = 20 days ).

关键词： Leishmania ATPase f 1 ATPase Electrophoresis Kinetics ATPase adenosine triphosphatase EGTA ethyleneglycol-bis ( β -aminoethyl ether)- N , N ′-tetraacetic acid P i inorganic phosphate TCA trichloroacetic acid MB membrane-bound SKEA sucrose-KCl-EDTA-ATP

来源：评论

学校读者我要写书评

暂无评论

EffECTS Of DIVALENT-CATIONS ON 77-K fLUORESCENCE EMISSION AND ON MEMBRANE-PROTEIN PHOSPHORYLATION IN ISOLATED THYLAKOIDS Of THE CYANOBACTERIUM SYNECHOCOCCUS 6301

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1988年第1期934卷 87-95页

作者： SANDERS, CE ALLEN, Jf Department of Pure and Applied Biology University of Leeds Leeds U.K.

The effects of divalent cations (Mg2+;Ca2+;Zn2+) on the phosphorylation of membrane-bound polypeptides in Synechococcus thylakoids were investigated. The effects of divalent cation and ATP concentration on the corresponding changes in 77 K fluorescence emission were also measured. The light-dependent phosphorylation of a 15 kDa polypeptide was shown to be dependent also on the presence of divalent cations, with Mg2+ and Ca2+ being the most effective. The 15 kDa polypeptide did not become dephosphorylated in the dark. This was shown to be due to a lack of phosphatase activity in this thylakoid membrane preparation. The light-induced changes in 77 K fluorescence emission spectra of Synechococcus thylakoids were shown to be independent of divalent cation concentration, to occur in the absence of ATP, and to be irreversible. The results from fluorescence emission spectroscopy are contrary to the conclusions of previous work in our laboratory (Allen, J.f., Sanders, C.E. and Holmes, N.G. (1985) fEBS Lett. 193, 271-275). The results indicate that the changes in fluorescence emission do not arise from a transition to light State 2: they may result instead from photooxidation of chlorophylls of Photosystem II. Since the 77 K fluorscence changes do not report on state transitions, we conclude that their indepenence of ATP is not inconsistent with a role for reversible protien phosphorylation in state transitions in cyanobacteria.

关键词： Cyanobacterium Photosynthesis Thylakoid membrane Divalent cation Protein phosphorylation fluorescence spectrum, 77 K State 1–State 2 transition DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea PS Photosystem PQ plastoquinone f 0 fluorescence level when all PS II traps are open Hepes 4-(2-hydroxyethyl)-1-piperazineethanesulphonic acid λ ex excitation wavelength PAGE polyacrylamide gel electrophoresis

来源：评论

学校读者我要写书评

暂无评论

SEQUENCE AND OVER-EXPRESSION Of SUBUNITS Of ADENOSINE-TRIPHOSPHATE SYNTHASE IN THERMOPHILIC BACTERIUM PS3

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1988年第1期933卷 141-155页

作者： OHTA, S YOHDA, M ISHIZUKA, M HIRATA, H HAMAMOTO, T OTAWARAHAMAMOTO, Y MATSUDA, K KAGAWA, Y JICHI MED SCH DEPT BIOCHEM MINAMIKAWACHI TOCHIGI 32904 JAPAN CHUO UNIV FAC SCI & ENGN DEPT IND CHEM BUNKYO KU TOKYO JAPAN

The primary structures of all the subunits of thermophilic ATP synthase were determined, and its .alpha., .beta. and .gamma. subunits could be over-expressed in Escherichia coli, because these subunits were stable and reconstitutable. DNA of 7500 base pairs in length was found to contain a cluster of nine genes for subunits of ATP synthase. The order of their reading frames (size in base pairs) was: I(381):a(630):c(216):b(489):.delta.(537):.alpha.(1507):.gamma.(858):.beta.(1419):.epsilon.(396), I being a gene for a small hydrophobic, basic protein expressed in vitro. All the termini of Tf0f1 subunits were confirmed by peptide sequencing. Large quantities of the overexpressed thermophilic .alpha., .beta. and .gamma. subunits were prepared from the extract of E. coli, by a few purification steps.

关键词： ATP synthase Amino acid sequence Nucleotide sequence Subunit purification Gene expression f 0 f 1 ATP synthase stability f 0 f 1 ATP synthase Tf 0 f 1 thermophilic f 0 f 1 f 1 catalytic portion of f 0 f 1 Tf 1 thermophilic f 1 Ef 1 Escherichi coli f 1 , f 0 , proton channel portion of f 0 f 1 Tf 0 thermophilic f 0 Ef 0 Escherichia coli f 0 SDS sodium dode-cylsulfate

来源：评论

学校读者我要写书评

暂无评论

A LINKED fOREST MANIPULATION SYSTEM SEMANTICS RULES fOR AN ATTRIBUTED TRANSLATION GRAMMAR fOR PL/O

引用

INTERNATIONAL JOURNAL Of COMPUTER MATHEMATICS 1988年第1期24卷 1-28页

作者： MCCLUSKEY, CPS The Pennsylvania State University Computer Science Department Fogelsville PA 18051 United States

In this paper a linked forest manipulation system (abbreviated as LfMS) semantics rules is defined for an attributed translation grammar (abbreviated as ATG) for PL/0 defined and discussed by McCluskey [9]. The LfMS reflects the translation achieved by the ATG, which is the generation of theP-codes, used in the original interpreter by Wirth [12].

关键词： Program semantics linked forest manipulation system attributed translation grammar code generation PL/0 D D.3 D.3.1 f f.3 f.3.2

来源：评论

学校读者我要写书评

暂无评论

MODELS Of PROTEIN LATERAL ARRANGEMENTS IN LIPID BILAYER-MEMBRANES - APPLICATION TO ELECTRON-SPIN RESONANCE STUDIES Of CYTOCHROME-C OXIDASE

引用

CHEMISTRY AND PHYSICS Of LIPIDS 1988年第4期46卷 267-277页

作者： PINK, DA CHISHOLM, DM CHAPMAN, D UNIV LONDON ROYAL FREE HOSP SCH MED DEPT CHEM BIOCHEM LONDON NW3 2PF ENGLAND

We consider the situation of integral membrane proteins in a lipid bilayer matrix where the size of the polar group of the protein is important in determining the lateral packing of the proteins. We represent the cross-section of the protein hydrophobic core as a hexagon moving on a lattice, and represent the projection of the polar group onto the plane of the bilayer as a shape, parts of which overlap the hexagon. Lattice sites represent lipid molecules. We calculate the fraction of lipid molecules which are adjacent to the hydrophobic core of at least one protein. We use this data to consider the "motion restricted" spectrum observed in electron spin resonance (ESR) probe studies, and compute the dependence of the "motion restricted" fraction upon protein concentration. The resulting curves can be used to analyze ESR data in order to deduce the size and shape of the proteins'' polar segment. We have used the range of models examined to study the dependence upon protein concentration of the particular case of the "motion restricted" spectrum of a spin-labelled lipid freely diffusing or, alternatively, covalently bound to cytochrome c oxidase. We find that our calculations are in accord with a model where .apprx. 60 lipid molecules can fit around an isolated such protein in both halves of the bilayer, and where the polar segment is substantially anisotropic and extends laterally beyond the limits of the hydrophobic core. The latter is in accord with what is known about the structure of cytochrome c oxidase. We indicate further measurements that should be performed in order to establish more definitively the dependence of the "motion restricted" component upon protein concentration, giving the lipid protein ratios at which they should be performed, and we make predictions concerning the results. finally we argue for a particular unified way of plotting experimental data.

关键词： lipid bilayers protein distribution electron spin resonance cytochrome c oxidase ESR electron spin resonance DPH 1,6-diphenyl-1,3,5-hexatriene f i ( c ) the fraction of all the lipids in the bilayer which are adjacent to the hydrophobic core of at least one integral protein f i ( c ) the “motion restricted” component, as a fraction of the total spectrum, measured in an ESR spectrum g i ( c ) the fraction of all those lipids which are covalently bound to proteins which are adjacent to the hydrophobic core of at least one integral protein other than the one to which they are bound G i ( c ) the fraction of the ESR spectrum, contributed by labelled lipids covalently bound to proteins, which is due to “motion restricted” lipids c the concentration (in mole fraction) of integral proteins in the bilayer S maximum number of lipid molecules in one half of the bilayer which can be adjacent (in the “first layer”) to the hydrophobic core of an isolated integral protein n i number of “motion restricted” lipids n f number of “free” (or non-motion restricted) lipids N L / N P = L / P ratio of the number of lipid molecules to the number of proteins in the bilayer

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：