Circular dichroism and magnetic circular dichroism of nitrogenase proteins.

abstract：:We previously isolated a mutant of Escherichia coli that is preferentially affected in the synthesis of rRNA and has a mutation in the gene (accD) encoding a subunit of acetyl-CoA carboxylase. Using this mutant and other mutants of the pathway for fatty acid and phospholipid biosynthesis as well as cerulenin, a specif...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Seyfzadeh M,Keener J,Nomura M

更新日期：1993-12-01 00:00:00

abstract：:We have previously described how T and natural killer (NK) lineage commitment proceeds from common T/NK progenitors (p-T/NK) in the murine fetal thymus (FT), with the use of a clonal assay system capable of discriminating p-T/NK from unipotent T or NK lineage-committed progenitors (p-T and p-NK, respectively). The mol...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ikawa T,Fujimoto S,Kawamoto H,Katsura Y,Yokota Y

更新日期：2001-04-24 00:00:00

abstract：:The polyhedral borane ion [n-B20H18]2- reacts with liquid ammonia in the presence of a suitable base to produce an apical-equatorial (ae) isomer of the [B20H17NH3]3- ion, [1-(2'-B10H9)-2-NH3B10H8]3-. The structure of this product has been confirmed by 11B NMR spectroscopy and x-ray crystallography. This species underg...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Feakes DA,Shelly K,Knobler CB,Hawthorne MF

更新日期：1994-04-12 00:00:00

abstract：:Patients with hematological malignancies can be successfully treated with HLA-matched T cell-depleted allogeneic stem cell transplantation (alloSCT) and subsequent donor lymphocyte infusions (DLIs). The efficacy of DLI is mediated by donor T cells recognizing minor histocompatibility antigens (mHags) on malignant reci...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Griffioen M,van der Meijden ED,Slager EH,Honders MW,Rutten CE,van Luxemburg-Heijs SA,von dem Borne PA,van Rood JJ,Willemze R,Falkenburg JH

更新日期：2008-03-11 00:00:00

abstract：:Gonadotropin-releasing hormone (GnRH) is important in reproduction, although the mechanism of central hypogonadism in humans remains unclear. Because the GnRH neuron originates from the olfactory placode and migrates to the hypothalamus during development, central hypogonadism in humans could be caused by failure in n...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Radovick S,Wray S,Lee E,Nicols DK,Nakayama Y,Weintraub BD,Westphal H,Cutler GB Jr,Wondisford FE

更新日期：1991-04-15 00:00:00

abstract：:Calcicludine (CaC) is a 60-amino acid polypeptide from the venom of Dendroaspis angusticeps. It is structurally homologous to the Kunitz-type protease inhibitor, to dendrotoxins, which block K+ channels, and to the protease inhibitor domain of the amyloid beta protein that accumulates in Alzheimer disease. Voltage-cla...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schweitz H,Heurteaux C,Bois P,Moinier D,Romey G,Lazdunski M

更新日期：1994-02-01 00:00:00

abstract：:Purified inside-out vesicles from human erythrocytes were used to investigate the active transport of oxidized glutathione (GSSG). Incubation of vesicles and GSSG in the presence of ATP resulted in the transport of GSSG into the vesicles. When vesicles were incubated with reduced glutathione (GSH), no transport was ob...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kondo T,Dale GL,Beutler E

更新日期：1980-11-01 00:00:00

abstract：:Sera from 11 individuals which were classified as Lp(a-) by direct gel diffusion and by absorption tests showed the presence of Lp(a) lipoprotein when the sera were concentrated 120-fold. This Lp(a) antigen was demonstrated by gel diffusion to be indistinguishable from Lp-lipoprotein isolated from known Lp(a+) sera. T...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Harvie NR,Schultz JS

更新日期：1970-05-01 00:00:00

abstract：:Blocking CD28-B7 T-cell costimulation by systemic administration of CTLA4Ig, a fusion protein which binds B7 molecules on the surface of antigen-presenting cells, prevents rejection and induces tolerance in experimental acute allograft rejection models. We tested the effect of CTLA4Ig therapy on the process of chronic...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Azuma H,Chandraker A,Nadeau K,Hancock WW,Carpenter CB,Tilney NL,Sayegh MH

更新日期：1996-10-29 00:00:00

abstract：:The multisubunit enzyme aspartate transcarbamylase consists of six copies of two types of polypeptide chains, catalytic (C) and regulatory (R). A complex formed by the partial dissociation of this enzyme has been isolated. This species, which has the structure C(6)R(4), is a likely intermediate in the stepwise dissoci...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Evans DR,Pastra-Landis SC,Lipscomb WN

更新日期：1974-04-01 00:00:00

abstract：:Weakly oncogenic adenovirus 2 (Ad2)-transformed LSH hamster cells are sensitive to lysis by spontaneously cytolytic lymphoid cells and activated macrophages, whereas highly oncogenic simian virus 40 (SV40)-transformed LSH cells are relatively resistant to these nonspecific effector cells. Somatic cell hybrids formed b...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cook JL,Hauser J,Patch CT,Lewis AM Jr,Levine AS

更新日期：1983-10-01 00:00:00

abstract：:Current understanding of the integration of cell division and expansion in the development of plant lateral organs such as leaves is limited. Cell number is established during a mitotic phase, and subsequent growth into a mature organ relies primarily on cell expansion accompanied by endocycles. Here we show that the ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dewitte W,Scofield S,Alcasabas AA,Maughan SC,Menges M,Braun N,Collins C,Nieuwland J,Prinsen E,Sundaresan V,Murray JA

更新日期：2007-09-04 00:00:00

abstract：:A light beam hitting the retina produces an excitatory process; however, around the edge of the light beam, sensory cells are inhibited and lose their sensitivity. This combination of stimulation and inhibition produces a discrepancy between the luminance pattern presented to the eye and the brightness pattern that is...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Von Békésy G

更新日期：1972-04-01 00:00:00

abstract：:Asian patients with chronic hepatitis C (CHC) are known to have better virological responses to pegylated (Peg) IFN-based therapy than Western patients. Although IL28B gene polymorphisms may contribute to this difference, whether favorable hepatitis C virus (HCV) kinetics during treatment plays a role remains unclear....

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hsu CS,Hsu SJ,Chen HC,Tseng TC,Liu CH,Niu WF,Jeng J,Liu CJ,Lai MY,Chen PJ,Kao JH,Chen DS

更新日期：2011-03-01 00:00:00

abstract：:Many cells exhibit periodic transient increases in cytosolic calcium levels rather than a sustained rise when stimulated by a hormone or growth factor. We propose here a molecular model that accounts for periodic calcium spiking induced by a constant stimulus. Four elements give rise to repetitive calcium transients: ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Meyer T,Stryer L

更新日期：1988-07-01 00:00:00

abstract：:Splenic lymphocytes from a Lewis rat, immunized with purified estradiol-receptor complex of calf uterine nuclei, were fused with cells of three different mouse myeloma lines (P3-X63-Ag8, P3-NSI/I-Ag4-1, and Sp2/0-Ag14) to yield hybridoma cultures, 9% of which produced antibodies to the receptor protein (estrophilin). ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Greene GL,Fitch FW,Jensen EV

更新日期：1980-01-01 00:00:00

abstract：:Synthesis of the iron-storage protein ferritin is thought to be regulated at the translational level by the cytosolic content of chelatable iron. This response to iron is regulated by the iron-modulated binding to ferritin mRNAs of a repressor protein, the iron regulatory element-binding protein. From measurements mad...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Eisenstein RS,Garcia-Mayol D,Pettingell W,Munro HN

更新日期：1991-02-01 00:00:00

abstract：:CPEB, a cytoplasmic polyadenylation element-binding protein, plays an important role in translational control of maternal mRNAs in early animal development. During Xenopus oocyte maturation, CPEB undergoes a Cdc2-mediated phosphorylation- and ubiquitin-dependent degradation that is required for proper entry into meios...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Setoyama D,Yamashita M,Sagata N

更新日期：2007-11-13 00:00:00

abstract：:Histones play a crucial role in the organization of DNA in the nucleus, but their presence can prevent interactions with DNA binding proteins responsible for repair of DNA damage. Uracil is an abundant mutagenic lesion recognized by uracil DNA glycosylase (UDG) in the first step of base excision repair (BER). In nucle...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hinz JM,Rodriguez Y,Smerdon MJ

更新日期：2010-03-09 00:00:00

abstract：:Carbonic anhydrases (CAs; EC 4.2.1.1) are metalloenzymes present in mammals with 16 isoforms that differ in terms of catalytic activity as well as cellular and tissue distribution. CAs catalyze the conversion of CO2 to bicarbonate and protons and are involved in various physiological processes, including learning and ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schmidt SD,Costa A,Rani B,Godfried Nachtigall E,Passani MB,Carta F,Nocentini A,de Carvalho Myskiw J,Furini CRG,Supuran CT,Izquierdo I,Blandina P,Provensi G

更新日期：2020-07-07 00:00:00

abstract：:Viral genome packaging into capsids is powered by high-force-generating motor proteins. In the presence of all packaging components, ATP-powered translocation in vitro expels all detectable tightly bound YOYO-1 dye from packaged short dsDNA substrates and removes all aminoacridine dye from packaged genomic DNA in vivo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dixit AB,Ray K,Black LW

更新日期：2012-12-11 00:00:00

abstract：:Glutathione, an essential cellular antioxidant required for mitochondrial function, is not synthesized by mitochondria but is imported from the cytosol. Rat liver mitochondria have a multicomponent system that underlies the remarkable ability of mitochondria to take up and retain glutathione. At external glutathione l...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mårtensson J,Lai JC,Meister A

更新日期：1990-09-01 00:00:00

abstract：:All proteins of this world are constructed in compliance with the same rule. Accordingly, two totally unrelated proteins, on the average, share 30 identical tripeptides, two tetrapeptides, and one pentapeptide per 500 residues. With this in mind, the 221-residue-long influenza virus hemagglutinin II (IVHA-II), as a re...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ohno S

更新日期：1991-04-15 00:00:00

abstract：:The calcium-activated K(+) channel KCa3.1 plays an important role in T lymphocyte Ca(2+) signaling by helping to maintain a negative membrane potential, which provides an electrochemical gradient to drive Ca(2+) influx. To assess the role of KCa3.1 channels in lymphocyte activation in vivo, we studied T cell function ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Di L,Srivastava S,Zhdanova O,Ding Y,Li Z,Wulff H,Lafaille M,Skolnik EY

更新日期：2010-01-26 00:00:00

abstract：:A plasmid construct expressing the p66 version of the human immunodeficiency virus reverse transcriptase as a bacterial fusion protein was subjected to in vitro mutagenesis, and the resulting variant proteins were assayed to define the locations of the two major enzymatic activities. The DNA polymerase activity was lo...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Prasad VR,Goff SP

更新日期：1989-05-01 00:00:00

abstract：:Understanding interactions between membranes requires measurements on well-controlled systems close to natural conditions, in which fluctuations play an important role. We have determined, by grazing incidence X-ray scattering, the interaction potential between two lipid bilayers, one adsorbed on a solid surface and t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Hemmerle A,Malaquin L,Charitat T,Lecuyer S,Fragneto G,Daillant J

更新日期：2012-12-04 00:00:00

abstract：:Fetal cells, potentially usable for prenatal diagnosis, were sorted from maternal blood samples taken as early as 15 weeks of gestation. Immunogenetic and cytogenic criteria established the fetal origin of the observed cells: Y-chromatin-containing (male) cells were detected in the sorted sample if and only if the new...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Herzenberg LA,Bianchi DW,Schröder J,Cann HM,Iverson GM

更新日期：1979-03-01 00:00:00

abstract：:The gene for cytosolic phosphoenolpyruvate carboxykinase (GTP) [GTP:oxaloacetate carboxy-lyase (transphosphorylating), EC 4.1.1.32] from the rat was isolated from a recombinant library containing the rat genome in phage lambda Charon 4A. The isolated clone, lambda PCK1, contains the complete gene for phosphoenolpyruva...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Yoo-Warren H,Monahan JE,Short J,Short H,Bruzel A,Wynshaw-Boris A,Meisner HM,Samols D,Hanson RW

更新日期：1983-06-01 00:00:00

abstract：:The quorum sensing signal autoinducer-2 (AI-2) regulates important bacterial behaviors, including biofilm formation and the production of virulence factors. Some bacteria, such as Escherichia coli, can quench the AI-2 signal produced by a variety of species present in the environment, and thus can influence AI-2-depen...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Marques JC,Oh IK,Ly DC,Lamosa P,Ventura MR,Miller ST,Xavier KB

更新日期：2014-09-30 00:00:00

abstract：:Bacteriophage T3-induced RNA polymerase, upon copying its specific template, native T3 DNA, initiates RNA chains only with GTP. Denaturation of the DNA results in loss of template specificity for the polymerase. With denatured T3 DNA as template, T3 polymerase initiates RNA chains with both ATP and GTP, and the averag...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Maitra U,Huang HH

更新日期：1972-01-01 00:00:00