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INHIBITOR STUDIES Of METHIONYL-TRANSfER RNA TRANSfORMYLASE Of EUGLENA-GRACILIS

BIOCHIMICA ET BIOPHYSICA ACTA 1980年第1期613卷 73-78页

作者： GAMBINI, A CROSTI, P BIANCHETTI, R UNIV MILAN CNR CTR STUDIO BIOL CELLULARE & MOLEC PIANTE I-20133 MILAN ITALY

Inhibitor studies of the only known eukaryotic methionyl-tRNA transformylase (10-formyltetrahydrofolate:L-methionyl-tRNA N-transformylase, EC 2.1.2.9) were carried out. All the natural pteroylglutamic acid derivatives examined, with the exception of pteroylglutamic acid, are inhibitors. The most effective is 5-methyltetrahydrofolate (5-CH3-H4PteGlu) (KI = 3 .cntdot. 10-6 M), which is the only noncompetitive inhibitor of the enzyme. All the other derivatives tested are competitive, and H4PteGlu shows a cooperative inhibition. These and other data obtained with pteroylglutamic analogs show that, in contrast to the bacterial enzyme, Euglena transformylase is also inhibited by compounds without a fully reduced pyrazine ring and is very sensitive to compounds with a methyl group in position 5 or 10 of the pteridine ring.

关键词： 10-formyltetrahydrofolate: Met-tRNA f transformylase Inhibitor folate metabolism Pteroylglutamate analog (Euglena gracilis)

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STUDIES ON PHOSPHORYLCHOLINE-SPECIfIC T-CELL IDIOTYPES AND IDIOTYPE-SPECIfIC IMMUNITY

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MOLECULAR IMMUNOLOGY 1980年第7期17卷 823-831页

作者： BENCA, R QUINTANS, J KEARNEY, Jf fLOOD, PM SCHREIBER, H UNIV CHICAGO DEPT PEDIATCHICAGOIL 60649 UNIV CHICAGO DEPT PATHOLCHICAGOIL 60649 UNIV ALABAMA CTR CANCBIRMINGHAMAL 35294 UNIV ALABAMA DEPT MICROBIOLBIRMINGHAMAL 35294

Because of the restricted heterogeneity of idiotypes generated in the course of antiphosphorylcholine (PC) ∗ immune responses and the availability of idiotype-specific probes, we studied idiotypic and anti-idiotypic murine T cells in the PC system. PC-specific helper activity was assayed in mice expressing varying levels of humoral HOPC-8 (H8) idiotype and inhibited with both conventional anti-H8 antiserum produced in A/He mice and a monoclonal anti-H8 reagent obtained from a hybridoma. Our results using the conventional anti-H8 indicate that T cell receptors bearing H8 idiotypic determinants are produced in the absence of circulating H8 antibody, and that H8 idiotype expression by T and B cells in the same mouse may not show parallel expression of idiotypes. The monospecific anti-H8 Ig could suppress H8-positive B cell responses but was incapable of inhibiting PC-specific T cells. The implications of these findings are discussed. furthermore, we demonstrate that immunization with purified anti-PC idiotype generates T cells which regulate the proliferation of idiotype-bearing myeloma cells.

关键词： (MGG) BALB/c IgG (KLH) keyhole limpet hemocyanin (PC) phosphorylcholine (TNP) trinitrobenzene sulfonic acid (NB f 1 ) f 1 hybrids of CBA/N♀ × BALB/c♂ (H8) HOPC-8 (M-167) MOPC-167 (M-315) MOPC-315 (167-MP) MOPC-167 myeloma protein (315-MP) MOPC-315 myeloma protein (DMEM) Dulbecco's modified Eagle's medium (CfA) complete freund's adjuvant (MLTC) mixed lymphocyte-tumor cell culture ([ 3 H]TdR) tritium-labeled thymine-deoxyribose (PfC) plaque-forming cell

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RESTORATION Of REfLEX VENTILATORY RESPONSE TO HYPOXIA AfTER REMOVAL Of CAROTID-BODIES IN THE CAT

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NEUROSCIENCE 1980年第3期5卷 573-580页

作者： SMITH, PG MILLS, E DUKE UNIV SCH MED DEPT PHARMACOL DURHAM NC 27710 USA

In mammals there are 2 sets of peripheral arterial chemoreceptors, the carotid bodies innervated by the sinus branch of the glossopharyngeal nerve and the aortic bodies innervated by the vagus nerves. The afferent impulse discharge from both receptors increases during hypoxia and there is a reflexly mediated increase in ventilation (hypoxic hyperventilation). This response was tested by exposing anesthetized cats to decreased inspired O2 concentration before and up to 315 days after bilateral resection of the carotid bodies. Acutely after removing the carotid bodies, hypoxic hyperventilation was abolished. The reflex pathway from the aortic body receptors normally contributes minimally to hypoxic hyperventilation. Subsequently, there was a restoration of hypoxic hyperventilation. Restoration was significant 30-43 days after removing the carotid bodies, it reached 70% of the preoperative value at 93-111 days and was essentially complete in terminal experiments 260-315 days after carotid body resection. In terminal experiments, hypoxic hyperventilation was not affected by recutting the regenerated carotid sinus nerves but was abolished completely by bilateral transection of the cervical vagosympathetic trunks. The restored ventilatory response was due predominantly to an increase in rat of breathing while an increase in tidal volume was predominant before carotid body resection. Resting ventilation breathing room air was not consistently decreased after carotid body resection while expired CO2 was elevated from day 20 to day 111 and at the preoperative level in terminal experiments. Restoration of hypoxic hyperventilation in the cat after carotid body resection is mediated by the reflex pathway from aortic body chemoreceptors. The possible contribution of chemoreceptive regenerated carotid sinus nerve axons was excluded. Restoration may be a consequence of the central reorganization of chemoreceptor afferent pathways consequent to interruption of the carotid body refl

关键词： f rate of breathing P ET CO 2 expired end tidal CO 2 concentration V E expired volume V E expired minute volume V T tidal volume

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DETERMINATION Of ACTIVATION-ENERGIES AND HALf-LIVES Of THERMO-LUMINESCENCE BANDS Of CHLOROPLASTS APPLYING THE METHOD Of MULTICOMPONENT CURVE RESOLUTION

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fEBS LETTERS 1980年第2期116卷 293-297页

作者： VASS, I HORVATH, G HERCZEG, T DEMETER, S HUNGARIAN ACAD SCI BIOL RES CTRINST PLANT PHYSIOLH-6701 SZEGEDHUNGARY JOZSEF ATTILA UNIV DEPT THEORET PHYSH-6722 SZEGEDHUNGARY JOZSEF ATTILA UNIV DEPT BIOPHYSH-6720 SZEGEDHUNGARY

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AMINO-ACID NEIGHBORHOOD RELATIONSHIPS IN PROTEINS - BREAKDOWN Of AMINO-ACID-SEQUENCES INTO OVERLAPPING DOUBLETS, TRIPLETS AND QUADRUPLETS

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INTERNATIONAL JOURNAL Of BIO-MEDICAL COMPUTING 1980年第1期11卷 67-75页

作者： ERHAN, S MARZOLf, T COHEN, L 2101 Chestnut Street Philadelphia PA 19103 U.S.A.

A method has been developed which allows the breakdown of an amino-acid sequence of proteins into overlapping di-, tripeptides, etc. The frequency of their distribution provides very convincing evidence that these sequences are non-random. These peptides have been demonstrated to be capable of being used as an objective key for the classification of organisms, and of proteins. It is also believed that they can be useful in increasing the accuracy of the prediction of protein folding. On a mis au point une méthode permettant de briser une chaîne amino-acide de protéines en donnant des dipéptides, tripéptides etc. se recouvrant partiellement. La fréquence de leur distribution prouve de façon très convaincante que ces chaînes ne sont pas aléatoires. On a montré que ces péptides peuvent être utilisées comme élément objectif de classification d'organismes et de protéines. On pense aussi qu'elles peuvent être utiles pour pour prévoir avec plus de précision le repliement des protéines.

关键词： A alanine C cysteine D aspartic acid E glutamic acid f phenylalanine G glycine H histidine I isoleucine K lysine L leucine M methionine N asparagine P proline Q glutamine R arginine S serine T threonine V valine W tryptophan Y tyrosine

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CONTROL Of ACTIVITY STATES Of HEART MITOCHONDRIAL ATPASE ROLE Of THE PROTON-MOTIVE fORCE AND CA2+

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第3期592卷 396-405页

作者： TUENADEGOMEZPUYOU, M GAVILANES, M GOMEZPUYOU, A ERNSTER, L UNIV STOCKHOLM ARRHENIUS LABDEPT BIOCHEMS-10691 STOCKHOLMSWEDEN CTR INVEST & ESTUDIOS AVANZADOS DEPT BIOQUIMMEXICO CITYDFMEXICO

The ATPase complex of submitochondrial particles exhibits activity transitions that are controlled by the natural ATPase inhibitor (Gómez-Puyou, A., Tuena de Gómez-Puyou, M. and Ernster, L. (1979) Biochim. Biophys. Acta 547, 252–257). The ATPase of intact heart mitochondria also shows reversible activity transitions; the activation reaction is induced by the establishment of electrochemical gradients, whilst the inactivation reaction is driven by collapse of the gradient. In addition it has been observed that the influx of Ca 2+ into the mitochondria induces a rapid inactivation of the ATPase; this could be due to the transient collapse of the membrane potential in addition to a favorable effect of Ca 2+ -ATP on the association of the ATPase inhibitor peptide to f 1 -ATPase. This action of Ca 2+ may explain why mitochondria utilize respiratory energy for the transport of Ca 2+ in preference to phosphorylation. It is concluded that the mitochondrial ATPase inhibitor protein may exert a fundamental regulatory function in the utilization of electrochemical gradients.

关键词： f 1 -ATPase Mitochondrial ATPase ATPase inhibitor Ca 2+ effect Proton-motive force EDTA ethylenediaminetetraacetic acid f 1 -ATPase soluble, oligomycin-insensitive mitochondrial ATPase fCCP carbonyl cyanide 4-trifluoromethoxyphenylhydrazone

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PROSTAGLANDIN STIMULATION Of CANINE PLATELET ADENYLATE-CYCLASE

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THROMBOSIS RESEARCH 1980年第1-2期19卷 119-124页

作者： LONGENECKER, GL KOPACIEWICZ, LJ PALMER, SJ PALMER, GC Department of Pharmacology University of South Alabama College of Medicine Mobile Alabama 36688 USA

Homogenates of washed canine platelets possessed an adenylate cyclase system that was potently activated by prostaglandin (PG) E1 and to a lesser extent by PGE2, PGA2 and ***.. The effect of the PG species on adenylate cyclase were not augmented by the GTP analog, 5''-guanylyl imidodiphosphate. The drug 1-epinephrine, a stimulator of canine platelet aggregation induced by other agents, acted as a weak inhibitor of the adenylate cyclase.

关键词： Adenylate Cyclase Prostaglandins (E 1 E 2 f 2a A 2 ) Canine Platelets Cyclic Adenosine-3′ 5′-monophosphate

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CONfORMATION AND STRUCTURE Of 9-ALPHA-D-ARABINOfURANOSYLADENINE

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BIOCHIMICA ET BIOPHYSICA ACTA 1980年第1期610卷 20-27页

作者： CLINE, SJ HODGSON, DJ UNIV N CAROLINA DEPT CHEM CHAPEL HILL NC 27514 USA

The crystal structure of the nucleoside 9-.alpha.-D-arabinofuranosyladenine (C10H13N5O4) was determined by 3-dimensional X-ray counter data. The adenosine analog crystallizes in space group P212121 of the orthorhombic system with 8 formula units in a cell of dimensions a, 6.720(5), b, 40.188(35), c, 8.357(8) .ANG.. Hence, there are 2 crystallographically independent molecules in the unit cell. The structure was solved by direct methods and refined by full-matrix least-squares techniques to a final value of the conventional R-factor of 0.076 using 1173 independent intensity data. In the crystal, both independent molecules (A and B) adopt the anti conformation (for an .alpha.-sugar), with glycosyl torsion angles, .chi., of -***. and -***.;these are comparable to values found in other .alpha.-nucleosides. The conformation about the extracyclic C(4'')-C(5'') bond is guache-guache in both molecules. The sugar pucker is C(2'')-exo-C(3'')-endo, 2T3, in molecule A and C(3'')-endo, 3E, in molecule B. Conformational analysis of rotation about the N(9)-C(1'') glycosyl bond was performed by use of CNDO[complete neglect of differential overlap]/2 molecular orbital calculations. The observed conformation may not be the global minimum, but it apparently lies only 0.4 kcal .cntdot. mol-1 higher in energy than the global minimum. The highest energy barrier to rotation around the glycosyl bond is calculated to be only 1.1 kcal .cntdot. mol-1, which is comparable to the value calculated for adenosine.

关键词： Arabinofuranosyladenine structure Conformation X-ray crystallography Molecular orbital calculation α -Ara f Ade 9-α-D-arabinofuranosyladenine β -Ara f Ade 9-β-D-arabinofuranosyladenine

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ULTRACRYOTOMY - DEVELOPMENT AND APPLICATION - WITH EXAMPLES fROM THE YEAST CYTOLOGY

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ACTA HISTOCHEMICA 1980年第1期66卷 59-84页

作者： BOHM, KJ Akademie der Wissenschaften der DDR Forschungszentrum für Molekularbiologie und Medizin Zentralinstitut für Mikrobiologie und Experimentelle Therapie Jena (Direktor: Prof. Dr. U. Taubeneck)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning and post-staining the sections for transmission electron microscopy) are submitted to critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. fundamental considerations of chemical prefixation and post-staining are supported by examples from yeast cytology. furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.

关键词： CHR Chromatin CW Zellwand E Einbettungsmedium ER endoplasmatisches Reticulum f filamentbündel K Proteinkristalle KT Kristall-assoziierte Tubuli M Mitochondrien MT Mikrotubuli der Mitosespindel N Kern NAO Kern-assoziiertes Organell NE Kernhülle NP Kernporen P Plasmamembran R Ribosomen T Tubuli V Vakuole

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THE ULTRASTRUCTURE Of CENTRIOLE IN MAMMALIAN TISSUE-CULTURE CELLS

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CELL BIOLOGY INTERNATIONAL REPORTS 1980年第11期4卷 1037-1044页

作者： VOROBJEV, IA CHENTSOV, YS A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry Moscow State University Moscow USSR

Structural polarity of centriole has been shown by analyzing serial sections of centrioles in the tissue culture cells of mouse, man, pig and Chinese hamster. Its major component is nine microtubule triplets. The inclination of the triplets towards the radius at the proximal end of the centriole is smaller than at the distal one. The internal tubule of the triplet has a smaller diameter than the middle and external ones; The triplets are bound by links of various nature all over their length. In the middle part, in the centriole lumen there is an amorphous hub; in the distal part, a thin fibre that is helically wound. In the proximal part, there are bases along the triplets, and handles stretch from the internal tubules. In the middle and distal parts, there are accumulations of an electron dense substance along the middle tubules. At the distal end, the centriole lumen is filled with an amorphous substance, whereas the proximal end is free from it. from outside, appendages are attached to the triplets at the distal end. The centriole structure is identical in all the cell types studied, except for those of Chinese hamster.

关键词： A B C inner middle outer triplet microtubules ap appendages tb triplet bases con connectives (A-C links) h hub f fibre rl ring of links in the middle part

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