Conformational changes induced in dihydrofolate reductase by folates, pyridine nucleotide coenzymes, and methotrexate.

abstract：:Because of increased numbers of recorded pertussis cases in the United States, this study sought to understand the role of nonmedical vaccine exemptions and waning immunity may have had on the resurgence of pertussis in the United States at the community level. We used geospatial scan statistics, SaTScan, version 9.4,...

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

authors： Aloe C,Kulldorff M,Bloom BR

更新日期：2017-07-03 00:00:00

abstract：:A (Mg(2+) + Ca(2+))ATPase (ATP phosphohydrolase, EC 3.6.1.3) has been purified from sarcoplasmic reticulum using a single step centrifugation procedure. The preparation is >95% pure by weight and contains only 25-30% of the lipid associated with the enzyme in native sarcoplasmic reticulum. The purified enzyme is unabl...

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

authors： Warren GB,Toon PA,Birdsall NJ,Lee AG,Metcalfe JC

更新日期：1974-03-01 00:00:00

abstract：:Antigen.antibody complexes (Ag.Ab) prepared from (125)I-labeled bovine serum albumin and guinea pig anti-albumin were incubated at 37 degrees C for 30 min with normal human serum diluted optimally for binding (1:16) and then with autologous erythrocytes (RBC). After washing, RBC-bearing antigen.antibody.complement com...

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

authors： Medof ME,Prince GM,Mold C

更新日期：1982-08-01 00:00:00

abstract：:Agrobacterium tumefaciens transfers the T-DNA portion of its Ti plasmid to the nuclear genome of plant cells. Upon cocultivation of A. tumefaciens strain A348 with regenerating tobacco leaf protoplasts, restriction endonuclease fragments of the T-DNA were generated that are consistent with double-stranded cleavage of ...

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

authors： Veluthambi K,Jayaswal RK,Gelvin SB

更新日期：1987-04-01 00:00:00

abstract：:For decades, scientists have debated whether supercooled liquids stop flowing below a glass transition temperature [Formula: see text] or whether motion continues to slow gradually down to zero temperature. Answering this question is challenging because human time scales set a limit on the largest measurable viscosity...

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

authors： Jadhao V,Robbins MO

更新日期：2017-07-25 00:00:00

abstract：:A type of heritable cellular change, known as habituation, occurs spontaneously in plant tissue and cell culture. This phenomenon is characterized by a newly acquired capacity of plant cells to produce growth regulatory substances. Using cloned lines of tobacco pith parenchyma cells, we demonstrated that a newly acqui...

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

authors： Binns A,Meins F

更新日期：1973-09-01 00:00:00

abstract：:Agricultural foods and technologies are thought to have eased the mechanical demands of diet-how often or how hard one had to chew-in human populations worldwide. Some evidence suggests correspondingly worldwide changes in skull shape and form across the agricultural transition, although these changes have proved diff...

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

authors： Katz DC,Grote MN,Weaver TD

更新日期：2017-08-22 00:00:00

abstract：:Aqueous gel sieving chromatography on Sephadex G-10 of the Group IA cations (Li+, Na+, K+, Rb+, Cs+) plus NH4+ as the Cl- salts, in combination with previous results for the halide anions (F-, Cl-, Br-, I-) as the Na+ salts [Washabaugh, M.W. & Collins, K.D. (1986) J. Biol. Chem. 261, 12477-12485], leads to the followi...

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

authors： Collins KD

更新日期：1995-06-06 00:00:00

abstract：:Novel antibiotics are urgently needed to combat multidrug-resistant pathogens. Venoms represent previously untapped sources of novel drugs. Here we repurposed mastoparan-L, the toxic active principle derived from the venom of the wasp Vespula lewisii, into synthetic antimicrobials. We engineered within its N terminus ...

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

authors： Silva ON,Torres MDT,Cao J,Alves ESF,Rodrigues LV,Resende JM,Lião LM,Porto WF,Fensterseifer ICM,Lu TK,Franco OL,de la Fuente-Nunez C

更新日期：2020-10-27 00:00:00

abstract：:The bactericidal effects of antibiotics are undoubtedly triggered by target-specific interactions, but there is growing evidence that an important aspect of cytotoxicity results from treatment-induced metabolic perturbations. In this study, we characterized molecular mechanisms whereby trimethoprim treatment results i...

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

authors： Giroux X,Su WL,Bredeche MF,Matic I

更新日期：2017-10-24 00:00:00

abstract：:The effects of the thymic polypeptide thymopoietin (Tpo) on the properties of the nicotinic acetylcholine receptor (AcChoR) were investigated by patch clamp techniques on mouse C2 myotubes and by biochemical assays on AcChoR-rich membrane fragments purified from the Torpedo marmorata electric organ. At high concentrat...

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

authors： Revah F,Mulle C,Pinset C,Audhya T,Goldstein G,Changeux JP

更新日期：1987-05-01 00:00:00

abstract：:We have constructed an opal suppressor system in Escherichia coli to complement an existing amber suppressor system to study the structural basis of tRNA acceptor identity, particularly the role of middle anticodon nucleotide at position 35. The opal suppressor tRNA contains a UCA anticodon and the mRNA of the suppres...

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

authors： McClain WH,Foss K,Jenkins RA,Schneider J

更新日期：1990-12-01 00:00:00

abstract：:Basal ganglia-thalamocortical circuits are critical for motor control and motor learning. Classically, basal ganglia nuclei are thought to regulate motor behavior by increasing or decreasing cortical firing rates, and basal ganglia diseases are assumed to reflect abnormal overall activity levels. More recent studies s...

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

authors： Kojima S,Kao MH,Doupe AJ

更新日期：2013-03-19 00:00:00

abstract：:Quaking(viable) (qk(v)) is a recessive neurological mouse mutation with severe dysmyelination of the CNS and spermiogenesis failure. The molecular lesion in the qk(v) mutant is a deletion of approximately 1 Mb on mouse chromosome 17 that alters the expression of the qk gene in oligodendrocytes. Complementation analysi...

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

authors： Lorenzetti D,Bishop CE,Justice MJ

更新日期：2004-06-01 00:00:00

abstract：:The intracellular activation of trypsinogen, which is both pH- and calcium-dependent, is an important early step in the development of acute pancreatitis. The cellular compartment in which trypsinogen activation occurs currently is unknown. We therefore investigated the site of intracellular trypsinogen activation by ...

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

authors： Sherwood MW,Prior IA,Voronina SG,Barrow SL,Woodsmith JD,Gerasimenko OV,Petersen OH,Tepikin AV

更新日期：2007-03-27 00:00:00

abstract：:Chronic sleep deprivation perturbs the circadian clock and increases susceptibility to diseases such as diabetes, obesity, and cancer. Increased inflammation is one of the common underlying mechanisms of these diseases, thus raising a hypothesis that circadian-oscillator components may regulate immune response. Here w...

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

authors： Narasimamurthy R,Hatori M,Nayak SK,Liu F,Panda S,Verma IM

更新日期：2012-07-31 00:00:00

abstract：:We have examined components of the preintegration complex of human immunodeficiency virus type 1 (HIV-1) and have analyzed features which govern the association of these components. HIV-1 nucleoprotein complexes, isolated from nuclear and cytoplasmic extracts of CD4+ cells after acute virus infection, contained viral ...

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

authors： Bukrinsky MI,Sharova N,McDonald TL,Pushkarskaya T,Tarpley WG,Stevenson M

更新日期：1993-07-01 00:00:00

abstract：:New neurons are generated in adult mammalians and may contribute to repairing the brain after injury. Here, we show that the number of new neurons in the dentate gyrus of adult rats increased in cerebral ischemic stroke and correlated with activation of the cAMP-response-element-binding protein (CREB). Inhibition of e...

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

authors： Zhu DY,Lau L,Liu SH,Wei JS,Lu YM

更新日期：2004-06-22 00:00:00

abstract：:The effect of the IgG from amyotrophic lateral sclerosis (ALS) patients was tested on the voltage-dependent barium currents (IBa) in mammalian dissociated Purkinje cells and in isolated P-type calcium channels in lipid bilayers. Whole cell clamp of Purkinje cells demonstrates that ALS IgG increases the amplitude of IB...

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

authors： Llinás R,Sugimori M,Cherksey BD,Smith RG,Delbono O,Stefani E,Appel S

更新日期：1993-12-15 00:00:00

abstract：:In this study, we used functional MRI (fMRI) at high field (3T) to track the time course of activation in the entire basal ganglia circuitry, as well as other motor-related structures, during the explicit learning of a sequence of finger movements over a month of training. Fourteen right-handed healthy volunteers had ...

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

authors： Lehéricy S,Benali H,Van de Moortele PF,Pélégrini-Issac M,Waechter T,Ugurbil K,Doyon J

更新日期：2005-08-30 00:00:00

abstract：:Studies of perception usually emphasize processes that are largely universal across observers and--except for short-term fluctuations--stationary over time. Here we test the universality and stationarity assumptions with two families of ambiguous visual stimuli. Each stimulus can be perceived in two different ways, pa...

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

authors： Wexler M,Duyck M,Mamassian P

更新日期：2015-12-01 00:00:00

abstract：:OLE (ornate, large, extremophilic) RNAs comprise a class of structured noncoding RNAs (ncRNAs) found in many extremophilic bacteria species. OLE RNAs constitute one of the longest and most widespread bacterial ncRNA classes whose major biochemical function remains unknown. In the Gram-positive alkaliphile Bacillus hal...

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

authors： Harris KA,Zhou Z,Peters ML,Wilkins SG,Breaker RR

更新日期：2018-07-03 00:00:00

abstract：:Quinate:NAD(+) 3-oxidoreductase (EC 1.1.1.24) from carrot cell suspension cultures has previously been shown to be activated by phosphorylation and inactivated by dephosphorylation. Here it is shown that the reactivation of the inactivated quinate:NAD(+) oxidoreductase is an enzyme-mediated process that requires ATP a...

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

authors： Ranjeva R,Refeno G,Boudet AM,Marmé D

更新日期：1983-09-01 00:00:00

abstract：:When mouse spleen cells were stimulated with irradiated xenogeneic, allogeneic, or trinitrophenyl-modified syngeneic lymphoid cells, the strongest cytolytic response was induced by alloantigens. Mouse cytolytic T lymphocytes generated to rat lymphoid cells demonstrated specificity for the immunizing rat strain, but ex...

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

authors： Burakoff SJ,Ratnofsky SE,Benacerraf B

更新日期：1977-10-01 00:00:00

abstract：:Using defined oligomers of IgE, our group previously studied the quantitative relationship between the aggregation of the high affinity receptors for IgE (Fc epsilonRI) and the earliest signals initiated by such aggregation: the phosphorylation of tyrosines on the receptor. Notably, at certain doses of the oligomers s...

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

authors： Torigoe C,Goldstein B,Wofsy C,Metzger H

更新日期：1997-02-18 00:00:00

abstract：:UV-sensitive syndrome (UVsS) is a rare autosomal recessive disorder characterized by photosensitivity and mild freckling but without neurological abnormalities or skin tumors. UVsS cells show UV hypersensitivity and defective transcription-coupled DNA repair of UV damage. It was suggested that UVsS does not belong to ...

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

authors： Horibata K,Iwamoto Y,Kuraoka I,Jaspers NG,Kurimasa A,Oshimura M,Ichihashi M,Tanaka K

更新日期：2004-10-26 00:00:00

abstract：:We examined the DNA and RNA of fresh leukemic cells (five patients) and long-term cultured T lymphocytes (four patients) from patients with adult T-cell leukemia for the presence of human T-cell leukemia virus (HTLV-I) sequences. In all cases HTLV-I provirus was found and several species of viral mRNAs were observed i...

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

authors： Franchini G,Wong-Staal F,Gallo RC

更新日期：1984-10-01 00:00:00

abstract：:Copper is an essential micronutrient that plays a central role for a broad range of biological processes. Although there is compelling evidence that the intracellular milieu does not contain any free copper ions, the rapid kinetics of copper uptake and release suggests the presence of a labile intracellular copper poo...

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

authors： Yang L,McRae R,Henary MM,Patel R,Lai B,Vogt S,Fahrni CJ

更新日期：2005-08-09 00:00:00

abstract：:In North America there are two generally recognized pathotypes (pathotypes 1 and 2) of the fungus Entomophaga grylli which show host-preferential infection of grasshopper subfamilies. Pathotype 3, discovered in Australia, has a broader grasshopper host range and was considered to be a good biocontrol agent. Between 19...

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

authors： Bidochka MJ,Walsh SR,Ramos ME,St Leger RJ,Silver JC,Roberts DW

更新日期：1996-01-23 00:00:00

abstract：:Prior incubation of quiescent cultures of Swiss 3T3 cells with vasopressin leads to loss of mitogenic stimulation on its subsequent addition in the presence of a synergistic growth factor. This desensitization is selective for vasopressin, requires prolonged incubation (half-maximal desensitization after 12 hr of trea...

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

authors： Collins MK,Rozengurt E

更新日期：1983-04-01 00:00:00