检索结果-内蒙古大学图书馆

LOCATION Of MANGANESE ATOMS IN PHOTOSYSTEM-II STUDIED BY ELECTRON-PARAMAGNETIC-RES POWER SATURATION Of SIGNAL-II SLOW

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1988年第2期936卷 259-268页

作者： ISOGAI, Y NISHIMURA, M IWAKI, M ITOH, S NATL INST BASIC BIOL OKAZAKI AICHI 444 JAPAN

Continuous-wave power saturation profile of EPR Signal IIslow (IIs) at K has been used to probe location of the manganese atoms in spinach Photosystem II (PS II) particles. There were at least two classes of the bound manganese atoms;two of the four atoms per PS II were loosely associated and the others were rather tightly associated. Both the classes of manganese were observed to interact magnetically with Signal IIs species (D+). The effectiveness of the loosely bound manganese on the electron-spin relaxation of D+ was little different from that of the tightly bound manganese, suggesting that these two classes of manganese exist at similar distances to D+. Illumination of the PS-II particles resulted in relief of the saturation. It was indicated that the relaxation of D+ was affected by the oxidation state of the manganese complex and also by the state of other component(s) of PS II. The effects of a free-radical-relaxing agent dysprosim (Dy) ion and its complex with EDTA were investigated in the presence and absence of the bound manganese atoms. Removal of the loosely bound manganese increased the accessibility of Dy3+ to D+ and decreased that of Dy-EDTA-, whereas further removal of manganese had little effect on the accessibilities of these agents. These results suggest that the lossely bound manganese atoms exist at exposed sites on the membrane surface, whereas the other manganese atoms are buried in the membrane.

关键词： Photosystem II EPR Manganese Signal II Oxygen evolution ( Spinach chloroplast ) Chl chlorophyll DCMU 3-(3,4)-dichlorophenyl-1,1-dimethylurea EPR electron paramagnetic resonance Mes 4-morpholineethanesulfonic acid PS II Photosystem II Signal II s II f and II vf , EPR Signal II slow , II fast and II very fast , respectively

来源：评论

学校读者我要写书评

暂无评论

SKIN-TESTS AND HISTAMINE-RELEASE WITH P-1-DEPLETED DERMATOPHAGOIDES-PTERONYSSINUS BODY EXTRACTS AND PURIfIED P-1

引用

JOURNAL Of ALLERGY AND CLINICAL IMMUNOLOGY 1988年第5期81卷 884-896页

作者： VANDERZEE, JS VANSWIETEN, P JANSEN, HM AALBERSE, RC UNIV AMSTERDAM EXPTL & CLIN IMMUNOL LABAMSTERDAMNETHERLANDS UNIV AMSTERDAM ACAD MED CTRDEPT PULMONOL1105 AZ AMSTERDAMNETHERLANDS

Monoclonal antibodies were raised against P1 and Dp X , two major allergens in Dermatophagoides Pteronyssinus extracts. The concentrations of IgE antibodies to P1 and Dp X in sera of mite-sensitive patients were determined in RAST with immunosorbent-bound monoclonal antibodies used for insolubilization of the allergens. The major allergen-specific IgE titers were compared with the total IgE response against D. pteronyssinus . The results of these serologic assays confirmed studies in the literature that P1 and Dp X are major allergens. The contribution of IgE anti-P1 to the total antimite response frequently exceeded 50% and, in general, appeared to be higher than the contribution of IgE anti-Dp X. Twenty percent of the mite-sensitive patients had no detectable IgE to either P1 or Dp X. The contribution of P1 to the biologic activity of D. pteronyssinus body extracts was derived from the effect of P1 depletion on the reactivity in the histamine-release test and skin test. This technique was preferred to the study of purified allergen because biologic activity of the nonabsorbed components is not affected. Immunization of rabbits with affinity-purified P1 yielded monospecific polyclonal antisera. Mite extracts depleted with either monoclonal or polyclonal anti-P1 were applied in the histamine-release test. The skin test was performed with extracts depleted with polyclonal anti-P1 . In addition, the activity of affinity-purified P1 was investigated in these tests. The results indicated that P1 depletion of D. pteronyssinus body extracts had no detectable effect on the activity in most patients, namely, at least 70% of the activity was retained in the depleted extract. There was a considerable variation between patients in the sensitivity for purified P1 , as compared to the sensitivity for whole D. pteronyssinus extracts. In the histamine-release test, the activity of purified P1 was up to 35% of the activity of the D. pteronyssinus body extract but did not exceed 10%

关键词： P 1 Der p I Dermatophagoides pteronyssinus antigen 1 Dp X Der p II Dermatophagoides pteronyssinus antigen 2 f 1 Der f I Dermatophagoides farinae antigen 1 fel d I felix domesticus antigen 1 SDS-PAGE Sodium dodecyl sulfate-polyacrylamide gel electrophoresis PBS-AT Phosphate-buffered saline containing 0.3 mg/ml of bovine albumin and 0.1% Tween 20 ALK Allergologisk Laboratorium Kopenhagen CSL Commonwealth Serum Laboratories

来源：评论

学校读者我要写书评

暂无评论

MEASUREMENT Of CYTO-TOXICITY BY TARGET-CELL RELEASE AND RETENTION Of THE fLUORESCENT DYE BIS-CARBOXYETHYL-CARBOXYfLUORESCEIN (BCECf)

引用

JOURNAL Of IMMUNOLOGICAL METHODS 1988年第1-2期108卷 255-264页

作者： KOLBER, MA QUINONES, RR GRESS, RE HENKART, PA Immunology Branch National Cancer Institute National Institutes of Health Bethesda MD 20892 U.S.A.

In order to utilize a newly available scanning microfluorimeter for lymphocyte-mediated cytotoxicity assays, a number of commercially available fluorescent dyes were campared for their suitability as target cell markers. One of them, bis-carboxyethyl-carboxyfluorescein (BCECf), was useful for assays with about 104 target cells and showed substantially less spontaneous leakage than other fluorescenin derivatives, while still leaking more rapidly than 51Cr. for short cytotoxicity incubations (less than 2 h) with cytotoxic T lymphocytes (CTL), the corrected percentage BCECf release into the supernatant parallels that of 51Cr. for 4 h assays cytotoxicity could be quantitated by measuring the BCECf retained by target cells. Using human CTL and natural killer (NK) cells as effectors, with a variety of lymphoid cells and fibroblasts as targets in 4 h assays, the BCECf retention technique was found to give cytotoxicity values comparable to the 51Cr release assay. Cytotoxicity assays measuring BCECf fluorescence in microtiter wells with the scanning microfluorimeter offer advantages of safety, economy, and processing time compared with the 51Cr release assay.

关键词： Cytotoxic cell Natural killer cell Cytotoxicity Cytotoxic T lymphocyte BCECf 2′ 7′-bis(carboxyethyl)-5 -6-carboxyfluorescein BCECf-AM acetoxymethyl ester of BCECf BSSH Hanks balanced salt solution containing 0.01 M Hepes, pH 7.4 Cf carboxyfluorescein CfDA carboxyfluorescein diacetate CICf dichlorocarboxyfluorescein CICfDA dichlorocarboxyfluorescein diacetate f fluorescein fDA fluorescein diacetate Sf sulfofluorescein SfDA sulfofluorescein diacetate SPDP N -succinimidyl 3-(2-pyridyldithio)proprionate DIDS 4 4′-disothiocyano-2 2′-disulfonic acid stilbene PBMC peripheral blood mononuclear cells

来源：评论

学校读者我要写书评

暂无评论

RECONSTITUTION Of THE PHOTOSYSTEM-I COMPLEX fROM THE P700 AND fX-CONTAINING REACTION CENTER CORE PROTEIN AND THE fA/fB POLYPEPTIDE

引用

fEBS LETTERS 1988年第1-2期240卷 9-14页

作者： GOLBECK, JH MEHARI, T PARRETT, K IKEGAMI, I Department of Chemistry Portland State University Portland OR 97207 USA

Complete restoration of electron flow from P700 to f A /f B was achieved by incubating a P700 and f x -containing photosystem (PS) I core protein from Synechococcus sp. 6301 with the 8.9 kDa, f A /f B polypeptide from spinach. The ESR spectrum of the reconstituted PS I complex shows nearly equal photochemical reduction of f A and f B when frozen in darkness and illuminated at 16 K. When illuminated during freezing, both f A and f B are quantitatively reduced and the spectrum is nearly indistinguishable from f A and f B in the control PS I complex. In the reconstituted PS I complex f x is photochemically reduced only in the presence of f − A and f − B , and the high-field resonance appears indistinguishable from f x in the control PS I complex. Optical flash photolysis after extensive washing confirms the complete restoration of the P700 + [f A /f B I-back-reaction, indicating quantitative rebinding of the 8.9 kDA polypeptide. This procedure represents the first reconstitution of the PS I complex from a purified PS I core protein and an isolated 8.9 kDa, f A /f B polypeptide, and makes possible independent manipulation of the two subunits that carry the entire electron acceptor system of PS I.

关键词： Photosystem I Reaction center Reconstitution Iron-sulfur center Core protein f A /f B protein PS, photosystem Chl, chlorophyll DCPIP, 2,6-dichlorophenolindophenol Photosystem I complex: multiprotein reaction center isolated with Triton X-100 containing P700 and acceptors A 0 A 1 f X f B and f A . Photosystem I core protein: reaction center heterodimer of psaA and psaB isolated from the photosystem I complex with chaotropes containing P700 and acceptors A 0 A 1 and f X . f A /f B polypeptide: 8.9 kDa polypeptide isolated by acetone precipitation containing iron-sulfur centers f A and f B . Reconstituted photosystem I complex: photosystem I core protein containing rebound f A /f B polypeptide

来源：评论

学校读者我要写书评

暂无评论

ENHANCEMENT BY ALLOXAN-INDUCED DIABETES Of THE RATE Of METABOLIC-ACTIVATION Of 3 PYROLYSATE CARCINOGENS VIA INCREASE IN THE P-448-H CONTENT IN RAT-LIVER

引用

BIOCHEMICAL PHARMACOLOGY 1988年第13期37卷 2503-2506页

作者： YAMAZOE, Y ABUZEID, M YAMAUCHI, K MURAYAMA, N SHIMADA, M KATO, R Department of Pharmacology School of Medicine Keio University Tokyo Japan.

Heterocyclic arylamines have been shown to be activated mainly by 3-MC-inducible P-448-H in rats. Thus, to verify the role of P-448-H in the mutagenic activation of Glu-P-1 in alloxan-induced diabetic rats, the numbers of revertants induced were compared with the hepatic content of P-448-H. A good correlation was observed between the mutagenic activating ability and the level of P-448-H in liver microsomes (r = 0.879). The results were also confirmed by the effective inhibition of Glu-P-1 activation by anti-P-448-H IgG. These results indicate that increased content of P-448-H is responsible for the enhanced capacity of mutagenic activation for heterocyclic arylamines in diabetic rat livers.

关键词： Glu-P-1 2-amino-6-methyldipyrido [1,2- a 3′,2′- d ]imidazole IQ 2-amino-3-methylimidazo [4,5- f ]quinoline MeIQx 2-amino-3,8-dimethyl imidazo[4,5- f ]quinoxaline 3-MC 3-methylcholanthrene Rev revertants P-448-H probably corresponds to P-450d (P-450IA2, recent nomenclature [1]) as determined by their pectral catalytic properties comparison in SDS gel [2]

来源：评论

学校读者我要写书评

暂无评论

A METHYL-COM METHYLREDUCTASE SYSTEM fROM METHANOGENIC BACTERIUM STRAIN GO1 NOT REQUIRING ATP fOR ACTIVITY

引用

fEBS LETTERS 1988年第1-2期241卷 60-64页

作者： DEPPENMEIER, U BLAUT, M JUSSOfIE, A GOTTSCHALK, G INST MIKROBIOL GRISEBACHSTR 8D-3400 GOTTINGENFED REP GER

Crude inside-out vesicles from the methanogenic strain Göl were prepared via protoplasts. These vesicles catalysed methane formation from methyl-CoM and H 2 at a maximal rate of 35 nmol/min · mg protein. Methane formation by the vesicles did not depend on the addition of ATP. This was in contrast to conventionally prepared crude extracts from the same organism or from Methanosarcina barkeri which exhibited strict ATP dependence of methanogenesis. ATP analogues inhibited methanogenesis by extracts to a much higher extent than that by vesicles. Both, particulate and soluble components prepared from the crude vesicles by ultracentrifugation were necessary for ATP-independent methane formation from methyl-CoM and H 2 . Hydrogenase activity was mainly associated with the particulate fraction whereas methyl-CoM methylreductase could be assigned to the soluble fraction. The detergent sulfobetaine inhibited methane formation from methyl-CoM without affecting hydrogenase or titanium citrate-dependent methylreductase activities, indicating that an additional membraneous component is involved in methanogenesis for methyl-CoM and H 2 .

关键词： Methane formation Methyl-CoM methylreductase Hydrogenase (Methanogenic bacteria) Na-CoM, sodium 2-mercaptoethane sulfonate f 420 , the ( N -L-lactyl-γ-L-glutamyl)-L-glutamic acid phosphodiester of 7,8-didemethyl-8-hydroxy-5-deazariboflavin-5′-phosphate methyl-CoM, methyl coenzyme M β,γ-methylene-ATP, adenylyl-(β,γ-methylene)diphosphate β,γ-imido-ATP, adenylyl-(β,γ-imido)-diphosphate diadenosine-P 5 , P 1 ,P 5 '-di-(adenosine-5′-)pentaphosphate dial-ATP, adenosine 5′-triphosphate-2′,3′-dialdehyde DTE, dithioerythritol PMSf, phenylmethanesulfonyl fluoride sulfobetaine, N -tetradecyl- N , N -dimethylammonio-3-propanesulfonate HS-HTP, 7-mercaptoheptanoylthreonine phosphate

来源：评论

学校读者我要写书评

暂无评论

A RECURRENCE fORMULA fOR THE DISTRIBUTION Of THE WILCOXON RANK SUM STATISTIC

引用

STATISTICS & PROBABILITY LETTERS 1988年第2期7卷 161-165页

作者： BRUS, T Department of Statistics University of British Columbia Vancouver Canada

A recurrence formula for the exact distribution of the Wilcoxon rank sum statistic is obtained using the properties of the binomial coefficients. A geometric interpretation of this distribution based on the structure ... 详细信息

关键词： Wilcoxon rank sum statistic W n N frequency f n N Pacal triangle triangulated number

来源：评论

学校读者我要写书评

暂无评论

MITOCHONDRIAL PROTEIN IMPORT - DIffERENTIAL RECOGNITION Of VARIOUS TRANSPORT INTERMEDIATES BY ANTIBODIES

引用

fEBS LETTERS 1988年第1期229卷 25-29页

作者： SOLLNER, T PfANNER, N NEUPERT, W Institut für Physiologische Chemie Universität München FRG.

The precursors of the mitochondrial proteins ADP/ATP carrier (AAC) and f1-ATPase subunit beta (f1 beta) were accumulated at the stages of binding to receptor sites on the mitochondrial outer membrane, or in contact sites between outer and inner membranes. Specific antibodies raised against the mature proteins were added to the isolated mitochondria and efficiently bound to these translocation intermediates. further movement of the precursors to consecutive steps along their import pathway was thereby inhibited. Controls showed that precursor proteins which were inserted into or translocated across the outer membrane were not recognized by the antibodies unless the mitochondrial membranes were disrupted. We conclude that the trapped translocation intermediates have antigenic sites exposed to the outside of the outer membrane.

关键词： Mitochondria Protein import ADP/ATP carrier f 1 -ATPase subunit β

来源：评论

学校读者我要写书评

暂无评论

DIffERENTIAL SCANNING CALORIMETRIC ANALYSIS Of ANTIfREEZE PROTEIN-ACTIVITY IN THE COMMON MEALWORM, TENEBRIO-MOLITOR

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1988年第2期957卷 217-221页

作者： HANSEN, TN BAUST, JG SUNY BINGHAMTON CTR CRYOBIOL RES BINGHAMTON NY 13901 USA

Antifreeze proteins(AfP) are able to inhibit the growth of ice-crystals at temperatures below the equilibrium point (Tf) of hemolymph. The analysis of AfP actvity has commonly involved the use of direct microscopic observation of a sample following inoculation with ice. The resulting activity, defined as the amount of thermal hysteresis observed between Tf and the subsequent rapid growth of ice, has been reported to range up to 7 .degree.C. However, most studies report high level of variation, possibly due to ice-crystal size variability and the presence of non-visible ice nuclei. We describe a new method of analysis of AfP activity using differential scanning calorimetry (DSC). DSC analysis reveals much higher activity, up to 10 .degree.C with less variation observed within a sample, and is not subject to the difficulty of accurate assessment of ice-crystal volume.

关键词： Antifreeze protein Protein activity DSC, differential scanning calorimetry ( T. molitor ) AfP antifreeze proteins T f equilibrium freezing point T hy hysteretic freezing point T m equilibrium melting point DSC differential scanning calorimetry

来源：评论

学校读者我要写书评

暂无评论

BIOSYNTHESIS Of PSORALENS - PSORALEN 5-MONOOXYGENASE ACTIVITY fROM ELICITOR-TREATED AMMI-MAJUS CELLS

引用

fEBS LETTERS 1988年第2期239卷 263-265页

作者： HAMERSKI, D MATERN, U UNIV FREIBURG INST BIOL 2LEHRSTUHL BEHAV MEDSCHANZLESTR 1D-7800 FREIBURGFED REP GER

Microsomes prepared from cultured Ammi majus cells that had been challenged for 14 h with an elicitor derived from the cell walls of Phytophthora megasperma ***. glycinea (Pmg) converted psoralen to bergaptol (5-hydroxypsoralen) in the presence of NADPH and oxygen. The enzymatic activity was characterized as an inducible cytochrome-P-450-dependent monooxygenase associated with the endoplasmic reticulum. All of the steps involved in bergapten (5-methoxypsoralen) biosynthesis in Ammi majus have now been demonstrated in vitro. The results suggest that bergaptol and not hydroxymarmesin in the precursor of bergapten.

关键词： Elicitor enzyme induction Psoralen biosynthesis Cytochrome P-450 monooxygenase furanocoumarin phytoalexin ( Ammi majus ) Pmg elicitor, elicitor preparation from cell walls of Phytophthora megasperma f.sp. glycinea R f , mobility relative to solvent front TLC, thin-layer chromatography DTE, 1,4-dithioerythritol.

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：