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LOCATION Of THE AROMATIC BINDING-SITE AND PREPARATION Of AN AROMATIC DERIVATIVE Of GLYCOGEN-PHOSPHORYLASE

BIOCHIMICA ET BIOPHYSICA ACTA 1980年第2期613卷 370-380页

作者： THOMAS, TP PHILIP, G UNIV COCHIN DEPT MARINE SCI COCHIN 682016 INDIA

Rabbit muscle glycogen phosphorylase b (EC 2.4.1.1) was inactivated by 1,5-difluoro-2,4-dinitrobenzene at pH 7.6 at a rate much faster than by 1-fluoro-2,4-dinitrobenzene. The reaction was very specific at low concentration of 1,5-difluoro-2,4-dinitrobenzene. Glucose-1-phosphate, G-6-P, AMP and ATP afforded protection against inactivation by 1,5-difluoro-2,4-dinitrobenzene. These results and kinetic analyses of the modified enzyme were used to locate the binding site for aromatic compounds in phosphorylase. The above ligands and aromatic compounds bound on the enzyme in the same region which is located near the monomer/monomer interface. An apparently homogeneous dinitrodiphenylene derivative of phosphorylase b with only 1 group/dimeric enzyme and having 50% of the catalytic activity was prepared. This derivative, in which the subunits were not crosslinked by the reagent, was devoid of the homotropic cooperativity for the substrate or activator sites even in the presence of allosteric inhibitors. Glucose behaved quite differently from other ligands in its effect on modification and on the kinetics of the modified enzyme. The significance of the glucose site is discussed.

关键词： Aromatic binding site Glycogen phosphorylase Chemical modification f 2 DNB 1,5-difluoro-2,4-dinitrobenzene fDNB 1-fluoro-2,4-dinitrobenzene

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PLANT INHIBITORS Of SERINE PROTEINASES - HAGEMAN-fACTOR fRAGMENT, KALLIKREINS, PLASMIN, THROMBIN, fACTOR-XA, TRYPSIN, AND CHYMOTRYPSIN

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THROMBOSIS RESEARCH 1980年第2期20卷 163-171页

作者： HOJIMA, Y PIERCE, JV PISANO, JJ Section on Physiological Chemistry Laboratory of Chemistry National Heart Lung and Blood Institute Bethesda Maryland 20205 U.S.A.

Numerous plants were tested for ihibitors of human Hageman factor fragment (Hff), plasma kallikrein, urinary kallikrein, plasmin, thrombin, porcine pancreatic kallikrein and bovine factor Xa, trypsin, and chymotrypsin. Pumpkin seeds and iris bulbs contain trypsin inhibitors which specifically inhibit Hff. flower *** those of tulip, lily, hyacinth, and *** unrecognized rich sources of inhibitors with different inhibitory spectrums and physicochemical properties.

关键词： Hageman factor fragment inhibitor kallikrein inhibitor trypsin inhibitor Hf f Hageman factor fragment TAME N α -tosyl-L-arginine methyl ester BTEE N-benzoyl-L-tyrosine ethyl ester IU inhibitor unit M r molecular weight

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IDENTIfICATION Of AN INTRAMOLECULAR CROSS-LINK IN TROPONIN-C AfTER CROSS-LINKING THE TROPONIN COMPLEX WITH 1,3-DIfLUORO-4,6-DINITROBENZENE

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第2期625卷 304-309页

作者： GUSEV, NB SAJGO, M fRIEDRICH, P HUNGARIAN ACAD SCI BIOL RES CTR INST ENZYMOL POB 7 H-1502 BUDAPEST HUNGARY

The troponin complex isolated from rabbit skeletal muscle was cross-linked with 1,3-difluoro-4,6-dinitrobenzene, subjected to tryptic hydrolysis, and the labeled peptides were separated. One peptide was purified to homogeneity;it was peptide Gly(89)-Arg(100) of troponin C on the basis of amino acid composition and N-terminal analysis. The absorption spectrum of this peptide between 300 and 500 nm was very similar to that of 1-(S-cysteinyl)-5-(***.-lysyl)-2,4-dinitrobenzene, which could only be due to cross-link formation between Lys-90 and Cys-98. This finding is interpreted in terms of the proposed tertiary structure of troponin C.

关键词： Troponin C cross-linking Side-chain topology Peptide analysis Difluorodinitrobenzene f 2 DNB 1,3-difluoro-4,6-dinitrobenzene EGTA ethylene glycol bis( β -aminoethyl ether)- N , N , N ′, N ′-tetraacetic acid

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OBSERVATION Of 2 QUENCHERS Of CHLOROPHYLL fLUORESCENCE IN CHLOROPLASTS AT -196-DEGREES-C

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第3期592卷 559-564页

作者： HORTON, P BAKER, NR UNIV ESSEX DEPT BIOLCOLCHESTER CO4 3SQESSEXENGLAND

fluorescence induction at −196°C has been monitored in chloroplasts rapidly frozen after poising at different redox potentials at room temperature. It was found that, as at room temperature, the initial level of fluorescence observed upon shutter opening ( f o ), relative to the final level observed after 10 seconds of illumination (f m ) increased as the redox potential of the chloroplasts was lowered. Redox titration revealed the presence of two quenching components with E m,7.8 at −70 mV and −275 mV accounting for approx. 75% and 25% of the variable fluorescence ( f v ). Parallel observation of fluorescence yield at room temperature similarly gave two components, with E m,7.8 at −95 mV and −290 mV, also accounting for approx. 75% and 25%. Simultaneous measurement of fluorescence emission at −196°C at 695 nm and 735 nm indicated that both emissions are quenched by the same redox components.

关键词： fluorescence quenching Redox potential Redox titration Chlorophyll (Pea chloroplast) E m midpoint oxidaton reduction potential Q the fluorescence quencher of Photosystem II PS I Photosystem I PS II Photosystem II f o initial fluorescence level f m final fluorescence level f v variable fluorescence, f m – f o

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CA-2+-INDUCED CONfORMATIONAL-CHANGES IN THE TROPONIN COMPLEX DETECTED BY CROSSLINKING

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第1期626卷 106-116页

作者： GUSEV, NB fRIEDRICH, P HUNGARIAN ACAD SCI BIOL RES CTR INST ENZYMOL H-1502 BUDAPEST HUNGARY

To detect Ca2+-induced conformational changes by crosslinking, rabbbit muscle troponin complex was reacted with the bifunctional reagents 1,3-difluoro-4,6-dinitrobenzene, 4,4''-difluoro-3,3''-dinitrodiphenylsulfone and dimethyl suberimidate under various conditions and the products were analyzed by dodecyl sulfate gel electrophoresis. In the absence of divalent cations, with the 2 aromatic reagents at a low reagent:protein ratio, the main crosslink products were troponin T-I and I-C. With dimethyl suberimidate, the only major crosslink product was conjugate T-I. Ca2+, alone and in the presence of Mg2+, prevented the formation of I-C crosslinks with both aromatic reagents. It did not affect crosslinking with dimethyl suberimidate. Ca2+ decreased the number of NH2 groups of troponin that are highly reactive towards 2,4,6-trinitrobenzene sulfonate. Both effects of Ca2+ can be interpreted in terms of a conformational change in the troponin complex elicited by the binding of the specific divalent cation.

关键词： Troponin complex Crosslinking Ca 2+ binding Conformational change Amino group reactivity EGTA ethyleneglycol-bis(β-aminoethylether)- N,N,N ′, N ′-tetraacetic acid f 2 DB 1,3-difluoro-4,6-dinitrobenzene f 2 DPS 4,4′-difluoro-3,3′-dinitrodiphenylsulfone SDS sodium dodecyl sulfate TNBS 2,4,6-trinitrobenzenesulfonate

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THE PATHOGENESIS Of PSEUDOTUMOR CEREBRI - A MATHEMATICAL-ANALYSIS

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JOURNAL Of THE NEUROLOGICAL SCIENCES 1980年第1期48卷 51-60页

作者： AISENBERG, RM ROTTENBERG, DA MEM SLOAN KETTERING CANC CTR DEPT NEUROLNEW YORKNY 10021 CORNELL UNIV COLL MEDDEPT NEUROLNEW YORKNY 10021

Although the clinical and laboratory features of pseudotumor cerebri have been clearly delineated, the pathogenesis of idiopathic pseudotumor remains a mystery. A number of pathogenetic mechanisms have been proposed to account for some or all of the observed cases. We describe a model relating changes in CSf outflow resistance and/or dural sinus venous pressure to observed changes in (i) CSf pressure, (ii) cerebral blood volume and (iii) the volume and hydrodynamic flow resistance of the ventriculosubarachnoid space.

关键词： CBV cerebral blood volume CSf cerebrospinal fluid CSfP cerebrospinal fluid pressure ICP intracranial pressure I f rate of CSf formation P d dural sinus venous pressure PVI pressure-volume index R a arachnoid villous flow resistance R s flow resistance of the convexity subarachnoid space R 1 s limiting value of R s R t total CSf outflow resistance SVP subarachnoid venous pressure

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ELECTROPHORETIC MOBILITIES Of HUMAN PERIPHERAL-BLOOD LYMPHOCYTES SUB-fRACTIONATED BY PARTITIONING IN 2 POLYMER AQUEOUS PHASE SYSTEMS

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第1期598卷 193-199页

作者： WALTER, H TAMBLYN, CH LEVY, EM BROOKS, DE SEAMAN, GVf UNIV CALIF IRVINE COLL MEDDEPT PHYSIOLIRVINECA 92717 UNIV OREGON HLTH SCI CTRDEPT NEUROLPORTLANDOR 97201 UNIV BRITISH COLUMBIA DEPT PATHOLVANCOUVER V6T 1W5BCCANADA UNIV BRITISH COLUMBIA DEPT CHEMVANCOUVER V6T 1W5BCCANADA

Mixtures of aqueous solutions of dextran and of poly(ethyleneglycol) form immiscible two-phase systems suitable for the separation (by partitioning) of cells based on subtle differences in their surface properties (Walter, H. (1977) in Methods of Cell Separation (Catsimpoolas, N., ed.), Vol. 1, pp. 307–354, Plenum Press, New York). Human peripheral blood lymphocytes were subjected to countercurrent distribution (a multiple-extraction procedure) in a charged phase system which yields fractions of cells enriched with respect to different surface markers (B-, T- and f c -receptor-bearing) and of different size (Walter, H., Webber, T.J., Michalski, J.P., McCombs, C.C., Moncla, B.J., Krob, E.J. and Graham, L.L. (1979) J. Immunol. 123, 1687–1695). The electrophoretic mobilities of cells in these fractions were measured by means of analytical particle electrophoresis (Bangham, A.D., flemans, R., Heard, D.H. and Seaman, G.V.f. (1958) Nature 182, 642–644). The bulk of B-lymphocytes had not only the lowest partition coefficient (i.e., lowest affinity for the top, positively charged phase) but also the lowest electrophoretic mobility, T-lymphocytes had a higher partition coefficient and mobility, and the population comprising most of the f c -receptor-bearing and largest lymphocytes had the highest partition coefficient but an intermediate mobility. The lymphocytes with highest mobility resolved by countercurrent distribution have yet to be characterized. The results with large and f c receptor-bearing lymphocytes again emphasize that the charges measured by cell electrophoresis and by partitioning are not necessarily the same. They also have as an important, practical consequence that populations enriched with respect to f c -receptor-bearing lymphocytes should be obtainable by a simple one- or two-step extraction process.

关键词： Dextran Poly(ethyleneglycol) Surface properties B-Lymphocyte f c -receptor T-Lymphocyte

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COMPLEMENTATION Of H-2 LINKED GENETIC-DEfECTS IN THE PRODUCTION AND fUNCTION Of ANTIGEN SPECIfIC SUPPRESSOR fACTOR - IMPLICATIONS fOR SUPPRESSOR-CELL ACTIVATION

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MOLECULAR IMMUNOLOGY 1980年第7期17卷 851-856页

作者： GERMAIN, RN Department of Pathology Harvard Medical School Boston MA 02115 U.S.A.

The physiologic basis of gene complementation for T cell mediated immune suppression specific for the synthetic polypeptide l -glutamic 50 acid- l -tyrosine 50 (GT) † was investigated. Previous studies had shown that inbred mice whose plaque forming cell response to GT coupled to methylated bovine serum albumin (GT-MBSA) is suppressed by prior GT challenge, produce a soluble T cell derived suppressor factor (GT-T s f), bearing I-J subregion coded determinants which induces a new set of suppressor T cells (T s2 ) in virgin spleen cell populations. H-2 a mice, such as A/J, are not suppressed by GT and fail to produce GT-T s f, but can be suppressed by GT-T s f via T s2 induction. H-2 b mice also fail to be suppressed by GT. (B6 × A) f 1 mice show complementation and are suppressed by GT. The present study demonstrates that B6 do produce GT-T s f, in contrast to A/J mice, but fail to be suppressed by this factor. (B6A) f 1 mice both produce and are suppressed by GT-T s f. The possible mechanisms (regulatory vs structural) able to account for these findings are discussed

关键词： GAT random terpolymer of l -glutamic acid 60 - l -alanine 30 - l -tyrosine 10 GT random copolymer of l -glutamic acid 50 - l -tyrosine 50 Is immune suppression MBSA methylated bovine serum albumin Mφ macrophage (antigen-presenting cell) PfC plaque forming cell SRBC sheep red blood cells (T,G)-A-L branched chain polymer ( l -tyr, l -glu)- dl -ala- l -lys T H f T cell derived helper factor T s suppressor T lymphocyte T s2 suppressor T cells induced by T s f T s f T cell derived suppressor factor

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PROTEOLYSIS Of SKELETAL-MUSCLE ADENYLATE-CYCLASE - DESTRUCTION AND RECONSTITUTION Of fLUORIDE AND GUANYLNUCLEOTIDE SENSITIVITY

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第3期631卷 393-401页

作者： DRUMMOND, GI NAMBI, P UNIV CALGARY DEPT CHEM BIOCHEM UNIT CALGARY T2N 1N4 ALBERTA CANADA

Adenylate cyclase was measured in skeletal muscle plasma membranes incubated with subtilisin. Under specific conditions the protease preferentially inactivated fluoride and guanylnucleotide sensitivity. following protease treatment, membranes were solubilized with Lubrol 12A9 and subjected to ion-exchange chromatography. Adenylate cyclase was eluted with 200 mM NaCl;the enzyme recovered was unresponsive to Naf or guanylyl imidodiphosphate. Responsiveness to the 2 ligands was restored by adding a heart fraction in which basal activity had been destroyed by heating at ***. C or by adding a soluble skeletal muscle fraction in which basal activity had been destroyed by N-ethylmaleimide. The solubilized subtilisin-treated skeletal muscle preparation may serve as a source of catalytic activity for the study and purification of regulatory factors for adenylate cyclase.

关键词： Adenylate cyclase f − sensitivity Proteolysis Guanylnucleotide (Skeletal muscle) Gpp(NH)p guanyl-5′-yl imidodiphosphate

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fORMATION Of EXCITED-STATES BY ION IMPACT ON SURfACES

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PROGRESS IN SURfACE SCIENCE 1980年第4期10卷 383-489页

作者： THOMAS, EW GEORGIA INST TECHNOL SCH PHYSATLANTAGA 30332

Impact of energetic ions on surfaces gives rise to a variety of excited states in the sputtered particles, in the reflected projectiles and sometimes of molecular species bound to the surface. Where the outer shell of the system is excited the state will normally decay with emission of optical photons that may be detected with conventional spectroscopy. Where there are vacancies in the inner shells the species may be detected by subsequent emission of Auger electrons or x-rays. The review provides a comprehensive catalogue of the available data and attempts to correlate the various observations. Optical emissions from sputtered and recoil particles are strongly influenced by radiationless de-excitation processes and this is incorporated into models that describe both line shape and line intensity. There is, however, no well developed description of how the excited states are formed. Thermal excitation models that describe excitation in terms of a Local Thermodynamic Equilibrium plasma are shown to be poorly founded. Alternative models ascribing excitation to bi-particle collision events have not yet been quantitatively tested. Inner shell excitation certainly appears to be governed by electron promotion events in the transient quasi-molecule formed by a projectile and target atom. We review briefly the possible applications of ion induced optical emission to the analysis of surface composition.

关键词： AES Auger Electron Spectroscopy BEA Binding Energy Approximation IBSCA Ion Beam Spectrochemical Analysis LTE Local Thermodynamic Equilibrium SCANIIR Surface Composition Analysis By Neutral and Ion Impact Radiation SIMS Secondary Ion Mass Spectroscopy S/I Normalized Stokes Parameter (Difference between right and left hand circularly polarized intensities divided by the sum of these two intensities) f

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