检索结果-内蒙古大学图书馆

ORGANOCOBALT-B12 MODELS - AXIAL LIGAND EffECTS ON THE STRUCTURAL AND COORDINATION CHEMISTRY Of COBALOXIMES

COORDINATION CHEMISTRY REVIEWS 1985年第APR期63卷 1-125页

作者： BRESCIANIPAHOR, N fORCOLIN, M MARZILLI, LG RANDACCIO, L SUMMERS, Mf TOSCANO, PJ EMORY UNIV DEPT CHEM ATLANTA GA 30322 USA UNIV TRIESTE IST CHIM I-34127 TRIESTE ITALY

来源：评论

学校读者我要写书评

暂无评论

fORMATION Of A NEW MUTAGENIC DIMEIQX COMPOUND IN A MODEL SYSTEM BY HEATING CREATININE, ALANINE AND fRUCTOSE

引用

MUTATION RESEARCH 1985年第2期151卷 177-183页

作者： GRIVAS, S NYHAMMAR, T OLSSON, K JAGERSTAD, M SWEDISH UNIV AGR SCI DEPT CHEM & MOLEC SCI S-75007 UPPSALA 7 SWEDEN UNIV LUND CTR CHEM DEPT NUTR S-22100 LUND SWEDEN

A mixture of creatinine, D-fructose and DL-alanine was heated in diethylene glycol containing 14% water for 2 h at ca. ***. C. The mutagent formed were extracted with 1-butanol, and purified by cation-exchange column chromatography, C18 reversed-phase Sep-Pak treatment and reversed-phase HPLC. According to its UV absorption, mass and 1H NMR spectra, one isolated fraction was tentatively assigned the chemical name, 3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxalin-2-amine (4,8-DiMeIQx). This finding is in agreement with the suggestion that sugars, amino acids and creatinine present in meat may be the precursors of the mutagenic imidazoquinolin- and imidazoquinoxalin-2-amines (IQ compounds).

关键词： IQ 3-methyl-3 H -imidazo[4,5- f ]quinolin-2-amine 76180-96-6 MeIQ 3,4-dimethyl-3 H -imidazo[4,5- f ]quinolin-2-amine 77094-11-2 MeIQx 3,8-dimethyl-3 H -imidazo[4,5- f ]quinoxalin-2-amine 77500-04-0 HPLC high-performance liquid chromatography

来源：评论

学校读者我要写书评

暂无评论

RELATIVE KINETICS Of QUENCHING Of PHOTOSYSTEM-II fLUORESCENCE AND PHOSPHORYLATION Of THE 2 LIGHT-HARVESTING CHLOROPHYLL A/B POLYPEPTIDES IN ISOLATED SPINACH THYLAKOIDS

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1985年第2期810卷 158-163页

作者： ISLAM, K JENNINGS, RC UNIV MILAN DEPARTIMENTO BIOL CNR CTR STUDIO BIOL CELLULARE & MOLEC PIANTE I-20133 MILAN ITALY

The kinetics of phosphorylation of the two light-harvesting chlorophyll a/b polypeptides in the presence of ATP, reduced plastoquinone and 5 mM Mg2+ shows increasing phosphorylation with time. The kinetics of quenching of the Photosystem II fluorescence at 5 mM Mg2+ does not parallel the observed kinetics of phosphorylation, but achieves a steady level of quenching after the first few minutes. By contrast, the fluorescence parameters of thylakoids phosphorylated in the presence of 5 mM Mg2+ and subsequently transferred to 2 mM Mg2+ exhibit a continuing decline in the phosphorylation-induced quending and a decrease in the fmfloration compared with the non-phosphorylated controls. The phosphorylation-induced quenching at the magnesium concentrations is discussed in terms of detachment of the light-harvesting chlorophyll a/b polypeptides from the Photosystem II matrix and ''spillover'' type mechanisms.

关键词： fluorescence quenching Mg 2+ effect Light-harvesting chlorophyll a b protein Photosystem II Protein phosphorylation (Spinach chloroplast) LHCP light-harvesting chlorophyll a b protein PS Photosystem f 0 non-variable fluorescence f m maximal fluorescence in the presence of DCMU DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea Tricine N -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine f m P fluorescence yield of the phosphorylated thylakoid membranes f m NP fluorescence yield of the nonphosphorylated thylakoid membranes

来源：评论

学校读者我要写书评

暂无评论

PHOTOSYNTHESIS AND CHLOROPLAST fUNCTIONING WITHIN INDIVIDUAL PUSTULES Of UROMYCES-MUSCARI ON BLUEBELL LEAVES

引用

PHYSIOLOGICAL PLANT PATHOLOGY 1985年第3期27卷 387-400页

作者： SCHOLES, JD fARRAR, Jf School of Plant Biology University College of North Wales Bangor Gwynedd LL57 2U W U.K.

Photosynthesis and chloroplast functioning is examined within pustules of Uromyces muscari on bluebell leaves at different stages of development from presporulation to green island formation. Green island tissue is shown to be photosynthetically active by 14CO2 fixation, O2 evolution and in vivo chlorophyll fluorescence kinetics. Chloroplast measurements indicate that, while, there is little reduction in chloroplast number per unit area in pustules of U. muscari, the chloroplast volume, the chlorophyll concentration and the ratio of chlorophyll a:b decline, suggesting that chlorophyll is lost from individual chloroplasts. Oxygen evolution, both per unit area and per unit chlorophyll, is reduced in pustules in comparison to green areas of an infected leaf and to uninfected leaves. Two major parameters of in vivo chlorophyll fluorescence kinetics (fvar and fq) are progressively reduced in pustules. This suggests that non-cyclic electron transport, and general chloroplast integrity, are impaired as the disease develops. These results are discussed in the context of current theories concerning the mechanisms by which parasites induce a block in the electron transport chain, and a new model is proposed, based on a change in the chlorophyll content of the photosystem reaction centres.

关键词： f 0 initial fluorescence level f max maximum fluorescence level f q fluorescence quenching capacity f var variable fluorescence LH light harvesting PS photosystem RC reaction centre

来源：评论

学校读者我要写书评

暂无评论

AN IMPROVEMENT fOR THE MCGILL-UNIVERSITY RANDOM NUMBER PACKAGE

引用

COMPUTATIONAL STATISTICS & DATA ANALYSIS 1985年第4期2卷 317-322页

作者： PIERCHALA, CE TEXAS TECH UNIV HLTH SCI CTRSCH MEDDEPT BIOMED ENGN & COMP MEDLUBBOCKTX 79430

This paper documents and provides code for two new entry points which increase the flexibility of the McGill University Random Number Package. With these additions the user can access internal locations containing the pseudo-random integers that control the random sequences produced by the generator. A detailed example of the use of the new entry points is provided. finally, some comments about the documentation of random number generators are made.

关键词： Random numbers Congruential generators Shift-register generators f ORTRAN IBM 360/370 Assembler Documentation

来源：评论

学校读者我要写书评

暂无评论

CHARACTERIZATION Of A PROTON PUMP fROM ACER-PSEUDOPLATANUS CELL MICROSOMES

引用

PLANT SCIENCE 1985年第1期40卷 25-33页

作者： BLEIN, JP SUTY, L ALLARD, MR SCALLA, R INRA AMELIORAT PLANTES STN F-21034 DIJON FRANCE

An Acer pseudoplatanus cell microsomal fraction was enriched in ATPase by sedimentation through a sucrose cushion and treatment with Triton X-100. This activity, which reached 0.9 .*** Pi min-1 mg-1 protein, was specific for ATP, slightly stimulated by K+, inhibited by orthovanadate and diethylstilbestrol, insensitive to oligomycin and azide, and had a Km-value of 0.51 mM for MgATP. ATP-dependent proton translocation was demonstrated by the .*** probe acridine orange. This activity had an optimum at pH 6.5, was substrate specific for ATP, and was strongly dependent on K+. Preparations of plasma membrane ATPase from A. pseudoplatanus cell culture thus possess biochemical properties analogous to other well characterized plant plasma membrane enzymes.

关键词： Acer pseudoplatanus microsomal vesicles ATPase plasma membrane proton translocation acridine orange BSA bovine serum albumin DES diethylstilbestrol DMSO dimethylsulfoxide IDPase inosinediphosphatase MES 2-(N- morpholino ) ethanesulfonic acid PhMeSO 2 f phenylmethylsulfonyl fluoride PNPP p- nitrophenylphosphate PNPPase p- nitrophenylphosphatase

来源：评论

学校读者我要写书评

暂无评论

IDENTIfICATION Of AN ESSENTIAL BETA-CHAIN LYSINE RESIDUE fROM BOVINE HEART MITOCHONDRIAL ATPASE SPECIfICALLY MODIfIED WITH NITROBENZOfURAZAN

引用

fEBS LETTERS 1985年第2期179卷 283-288页

作者： SUTTON, R fERGUSON, SJ UNIV BIRMINGHAM DEPT BIOCHEMPOB 363BIRMINGHAM B15 2TTW MIDLANDSENGLAND

A tetrapetide containing an essential lysine residue chemically modified with the nitrobenzofurazan group has been purified from bovine heart mitochondrial ATPase. The composition of the peptide indicates that this lysine is residue 401 in the sequence of a beta chain. The modification was achieved by incubation at pH 9 of ATPase that had been previously labelled on a single essential tyrosine residue by reaction of the enzyme with 4-chloro-7-nitrobenzofurazan. The specific transfer of the nitrobenzofurazan group from the tyrosine residue to a particular lysine residue is consistent with the previously demonstrated intramolecular character of this transfer reaction.

关键词： Mitochondrial ATP synthase Chemical modification Peptide purification Intramolecular shift f 0 f 1 -ATPase inhibition 4-Chloro-7-nitrobenzofurazan Nbf-Cl, 4-chloro-7-nitrobenzofurazan Nbf, nitrobenzofurazan

来源：评论

学校读者我要写书评

暂无评论

STEROLS Of KETOCONAZOLE-INHIBITED LEISHMANIA-MEXICANA-MEXICANA PROMASTIGOTES

引用

MOLECULAR AND BIOCHEMICAL PARASITOLOGY 1985年第3期15卷 257-279页

作者： GOAD, LJ HOLZ, GG BEACH, DH SUNY UPSTATE MED CTR DEPT MICROBIOL SYRACUSE NY 13210 USA UNIV LIVERPOOL DEPT BIOCHEM LIVERPOOL L69 3BX ENGLAND

l. mexicana promastigotes grown with cholesterol, supplied in natural products as the free sterol and as cholesteryl esters, were exposed to [2-14C]mevalonate and to the antimycotic drug ketoconazole. Growth was inhibited and cholesterol and ***.-methylsterols accumulated in free and esterified forms (cholesterol >>> ***.,***.-dimethylcholesta-8,***.-ol >> ***.-methylcholesta-8,***.-ol .simeq. ***.-methylergosta-8,24(28)-***.-ol >> ***.,***.-dimethylergosta-8,24(28)-***.-ol;identified by capillary gas chromatography/mass spectrometry, and by 1H and 13C NMR spectrometry). The ***.-methyl sterols were preferentially labeled with 14C. The cholesterol was unlabeled and substituted for a substantial fraction of the major product of sterol biosynthesis, ergosta-5,7,24(28)-***.-ol (5-dehydroepisterol), but did not replace it and did not offer remarkable protection against either growth inhibition or alteration of sterol biosynthesis. Promastigotes grown with [6-2H]cholesterol or [4-14C]cholesterol did not contain labeled forms of Leishmania sterols, or other sterols. The chromatographic and spectrometric sterol analyses and the isotopic tracer findings suggested that ketoconazole impaired the cytochrome P-450 dependent ***.-demethylation of lanosterol, that cholesterol was neither biosynthesized nor metabolized, and that the physiological function of 5-dehydroepisterol had sterol structural requirements not entirely met by cholesterol. In all these studies, L. mexicana demonstrated a sterol biochemistry remarkably similar to that of fungi. This recommends an increase in interest in antimycotic drugs as chemotherapeutic agents for leishmanial infections.

关键词： Leishmania Promastigotes Ketoconazole Sterols Membranes GLC gas-liquid chromatography TLC thin-layer chromatography CC column chromatography GC/MS gas chromatography/mass spectrometry NMR nuclear magnetic resonance spectrometry T rr relative retention time R f relative mobility

来源：评论

学校读者我要写书评

暂无评论

ORIENTED RECONSTITUTION Of RED-CELL MEMBRANE-PROTEINS AND ASSESSMENT Of THEIR TRANSMEMBRANE DISPOSITION BY IMMUNOQUENCHING Of fLUORESCENCE

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1985年第2期817卷 238-248页

作者： DARMON, A BARNOY, S GINSBURG, H CABANTCHIK, ZI HEBREW UNIV JERUSALEM INST LIFE SCI DEPT BIOL CHEM IL-91904 JERUSALEM ISRAEL

The 2 major membrane glycoproteins of human red cells, glycophorin and band 3, the anion exchange protein, were isolated from cells exofacially labeled with fluorescein and reconstituted into vesicles with defined transmembrane disposition. Uniform orientation of polypeptides was accomplished by 2 procedures: Vesicles with single protein units were obtained by a 1-step dilution of a protein/detergent suspension with a vast excess of phospholipid. Vesicles with uniform orientation of protein were selected by affinity chromatography on derivatized Sepharoses (organomercurial, wheat germ agglutinin, aminoethyl or diethylaminoethyl). Vesicles with multiple protein units with uniform orientation were generated by vectorial immobilization of detergent solubilized proteins on the above affinity matrices and in situ formation of proteoliposomes by detergent substitution for phospholipid. The proteoliposomes were released from the column by addition of excess free ligand. The orientation of band 3 and glycophorin in the reconstituted vesicles was first assessed by immunofluorescence quenching, using anti-fluorescein antibodies, to quantitatively quench fluorescein residues exposed on the outer surface of vesicles. further assessment was achieved by chromatographing the vesicles through various affinity and ionic matrices. Vesicle populations of higher than 90% homogeneity in protein orientation (right-side-out or inside-out) were obtained with both procedures. The above methods provide a convenient experimental tool for the oriented reconstitution of proteins and the evaluation of their transmembrane disposition.

关键词： Glycophorin Band 3 Membrane reconstitution Protein orientation Affinity chromatography Immunofluorescence quenching fluorescence quenching (Erythrocyte membrane) GPH glycophorin AEP anion exchange protein OSDS one-step dilution in suspension GDM gradual dilution on matrix f fluorescein Cf 5(6)-carboxyfluorescein IfQ immunofluorescence quenching LR lyssamine-rhodamine fTSC fluorescein-5-thiosemicarbazide fA fluorescein-5-amine [ 3 H]H 2 DIDS 4,4′-diisothiocyano-2,2′-dihydrostilbene disulfonic acid WGA wheat germ agglutinin pHMB p- hydroxymercuribenzoate EDC 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide fITC fluorescein-5-isothiocyanate AE amino ethyl PBS phosphate-buffered saline (147 mM NaCI, 20 mM sodium phosphate) 5P8 5 mM sodium phosphate (pH 8.0) 36P7.4 36 mM sodium phoshate (pH 7.4) high ionic strength buffer 150 mM sodium phosphate, 150 mM NaCl, (pH 7.4) CMC critical micellar concentration PC phosphatidylcholine TLCK tosyl-lysine-chloromethyl-ketone

来源：评论

学校读者我要写书评

暂无评论

THE SYNTHESIS AND MUTAGENICITY Of THE 3-ETHYL ANALOGS Of THE POTENT MUTAGENS IQ, MEIQ, MEIQX AND ITS 3,7-DIMETHYL ISOMER

引用

MUTATION RESEARCH 1985年第3期144卷 131-136页

作者： JAGERSTAD, M GRIVAS, S SWEDISH UNIV AGR SCI DEPT CHEM & MOLEC BIOL S-75007 UPPSALA SWEDEN

The title compounds were synthesized and tested for mutagenicity on Salmonella typhimurium TA98 in the presence of S9 mix. All test compounds showed lower activity than their respective 3-methyl analogues (IQ compounds). The replacement of the 3-methyl by an ethyl group should not alter the chemistry of these compouds;hence their lower mutagenic activity could merely be of steric origin.

关键词： Glu-P-1 6-methyl-5 H -dipyrido[1,2- a :3′,2′- d ]-imidazol-2-amine, 67730-11- Glu-P-2 5 H -dipyrido[1,2- a :3′,2′- d ]imidazol-2-amine, 67730-10-3 IQ 3-methyl-3 H -imidazo[4,5- f ]quinolin-2-amine, 76180-96-6 MeIQ 3,4-dimethyl-3 H -imidazo[4,5- f ]quinolin-2-amine, 77094-11-2 MeIQx 3,8-dimethyl-3 H -imidazo[4,5- f ]quinoxalin-2-amine, 77500-04-0 “7MeIQx” 3,7-dimethyl-3 H -imidazo[4,5- f ]quinoxalin-2-amine, 78411-56-0 Trp-P-1 1,4-dimethyl-5 H -pyrido[4,3- b ]indol-3-amine, 62450-06-0 Trp-P-2 1-methyl-5 H -pyrido[4,3- b ]-indol-3-amine 62450-07-1

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：