Abstract:
:The matrix of second derivatives of 21 apparent local energy minima of deca-L-alanine has been computed. The results show that all these conformations are true local energy minima and, therefore, potentially stable conformations for this peptide. Calculations of the relative statistical weights of these conformations confirm earlier theoretical considerations on the importance of the librational free energy of stable conformations of peptides. As predicted earlier, the relative statistical weights of the local energy minima do not always fall in the same order as the relative energies.
journal_name
Proc Natl Acad Sci U S Aauthors
Gibson KD,Scheraga HAdoi
10.1073/pnas.63.2.242subject
Has Abstractpub_date
1969-06-01 00:00:00pages
242-5issue
2eissn
0027-8424issn
1091-6490journal_volume
63pub_type
杂志文章abstract::Regulation of leukocyte integrin avidity is a crucial aspect of inflammation and immunity. The actin cytoskeleton has an important role in the regulation of integrin function, but the cytoskeletal proteins involved are largely unknown. Because inflammatory stimuli that activate integrin-mediated adhesion in human poly...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.16.9331
更新日期:1998-08-04 00:00:00
abstract::The high concentration of gonadotropin-releasing hormone (GnRH) in milk of several species implies that the mammary gland is either a site of synthesis for this neuropeptide or that it is efficiently concentrated from plasma by this organ. By PCR amplification of mammary gland cDNA, we have demonstrated expression of ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.11.4994
更新日期:1994-05-24 00:00:00
abstract::We measured the superconducting transition temperature of (6)Li between 16 and 26 GPa, and report the lightest system to exhibit superconductivity to date. The superconducting phase diagram of (6)Li is compared with that of (7)Li through simultaneous measurement in a diamond anvil cell (DAC). Below 21 GPa, Li exhibits...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1412638112
更新日期:2015-01-06 00:00:00
abstract::Nitrogen metabolism in bacteria and archaea is regulated by a ubiquitous class of proteins belonging to the P(II)family. P(II) proteins act as sensors of cellular nitrogen, carbon, and energy levels, and they control the activities of a wide range of target proteins by protein-protein interaction. The sensing mechanis...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1108038108
更新日期:2011-11-22 00:00:00
abstract::An exact treatment of adsorption from a one-dimensional lattice gas is used to eliminate and correct a well-known inconsistency in the Brunauer-Emmett-Teller (B.E.T.) equation-namely, Gibbs excess adsorption is not taken into account and the Gibbs integral diverges at the transition point. However, neither model shoul...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.25.14328
更新日期:1996-12-10 00:00:00
abstract::Myxococcus xanthus is a Gram-negative bacterium that aggregates to form fruiting bodies when nutrients are limiting. Previous studies showed that the frz mutants that are defective in chemotaxis exhibited irregular and infrequent patterns of cellular reversal. In contrast, wild-type cells, when examined individually, ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.9.4142
更新日期:1996-04-30 00:00:00
abstract::To determine whether the human pituitary contains a previously unidentified, nonprolactin (non-hPRL), non-growth-hormone (non-hGH) factor capable of stimulating mammary development, we tested the effects of whole human pituitary extract (hPE) and pituitary extracts depleted of hPRL and hGH ("stripped hPE") in hypophys...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.84.22.8110
更新日期:1987-11-01 00:00:00
abstract::Banded iron formations (BIFs) record a time of extensive Fe deposition in the Precambrian oceans, but the sources and pathways for metals in BIFs remain controversial. Here, we present Fe- and Nd-isotope data that indicate two sources of Fe for the large BIF units deposited 2.5 billion y ago. High-εNd and -δ(56)Fe sig...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1505515112
更新日期:2015-07-07 00:00:00
abstract::A photosensitizer conjugate, chlorin e6 (Ce6) covalently bound to 1-micron-diameter polystyrene microspheres, has been investigated in the photodynamic destruction of MGH-U1 human bladder carcinoma cells in vitro. The microspheres were taken up avidly by the carcinoma cells; confocal laser scanning fluorescence micros...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.4.1580
更新日期:1991-02-15 00:00:00
abstract::The nuclear receptors LXRalpha and LXRbeta have been implicated in the control of cholesterol and fatty acid metabolism in multiple cell types. Activation of these receptors stimulates cholesterol efflux in macrophages, promotes bile acid synthesis in liver, and inhibits intestinal cholesterol absorption, actions that...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.112059299
更新日期:2002-05-28 00:00:00
abstract::The knowledge of tropical palaeoclimates is crucial for understanding global climate change, because it is a test bench for general circulation models that are ultimately used to predict future global warming. A longstanding issue concerning the last glacial maximum in the tropics is the discrepancy between the decrea...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0610109104
更新日期:2007-06-05 00:00:00
abstract::We propose a phenomenological theory that accounts for entropic effects due to loop formation to predict pathways in the kinetics of protein folding. The theory, the basis of which lies in multiple folding pathways and a three-stage kinetics, qualitatively reproduces most of the kinetic measurements in the refolding o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.5.1277
更新日期:1995-02-28 00:00:00
abstract::The 24-hr intracarotid infusion of plasma-treated glycyl-L-glutamine (3 microM) produced significant enhancement of the monomeric G1 and tetrameric G4 forms of acetylcholinesterase of the cat superior cervical ganglion 48 hr after denervation, in comparison with denervated, noninfused controls. No significant effect o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.16.6215
更新日期:1988-08-01 00:00:00
abstract::Transient cytosolic Ca(2+) ([Ca(2+)](cyt)) elevations are early events in plant signaling pathways including those related to abiotic stress. The restoration of [Ca(2+)](cyt) to prestimulus levels involves ATP-driven Ca(2+) pumps, but direct evidence for an essential role of a plant Ca(2+)-ATPase in abiotic stress ada...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0800864105
更新日期:2008-12-09 00:00:00
abstract::The Madden-Julian oscillation (MJO) is the dominant mode of variability in the tropical atmosphere on intraseasonal timescales and planetary spatial scales. Despite the primary importance of the MJO and the decades of research progress since its original discovery, a generally accepted theory for its essential mechani...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0903367106
更新日期:2009-05-26 00:00:00
abstract::We describe preliminary studies of the pharmacokinetics, biodistribution, and excretion of an oligodeoxy-nucleotide phosphorothioate ([S]oligonucleotide) in mice. After either intravenous or intraperitoneal administration of a single dose (30 mg/kg of body weight), [S]oligonucleotide (35S-labeled at each internucleoti...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.17.7595
更新日期:1991-09-01 00:00:00
abstract::Delta 5-3-Ketosteroid isomerase (EC 5.3.3.1) promotes an allylic rearrangement involving intramolecular proton transfer via a dienolic intermediate. This enzyme enhances the catalytic rate by a factor of 10(10). Two residues, Tyr-14, the general acid that polarizes the steroid 3-carbonyl group and facilitates enolizat...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.16.8220
更新日期:1996-08-06 00:00:00
abstract::Fast lateral proton migration along membranes is of vital importance for cellular energy homeostasis and various proton-coupled transport processes. It can only occur if attractive forces keep the proton at the interface. How to reconcile this high affinity to the membrane surface with high proton mobility is unclear....
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1121227109
更新日期:2012-06-19 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0811313106
更新日期:2009-04-28 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.12.5331
更新日期:1991-06-15 00:00:00
abstract::The location of renin (EC 3.4.99.19) in rat pituitary was determined by the peroxidase-antiperoxidase immunohistochemical technique. By using antisera prepared with purified rat renal renin, an immunoreactive substance was localized within ovoid cells scattered throughout the anterior pituitary. These cells were shown...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.12.7579
更新日期:1981-12-01 00:00:00
abstract::The solution conformations of 2-substituted derivatives of 1-(beta-D-ribofuranosyl)benzimidazole have been determined by circular dichroism spectroscopy in aqueous solutions. It is shown that analogs with methyl, amino, or methylamino substituents at position 2 of the benzimidazole ring (position 8 of the purine ring)...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.2.553
更新日期:1979-02-01 00:00:00
abstract::The latency-associated nuclear antigen (LANA) of Kaposi sarcoma herpesvirus (KSHV) is mainly localized and functions in the nucleus of latently infected cells, playing a pivotal role in the replication and maintenance of latent viral episomal DNA. In addition, N-terminally truncated cytoplasmic isoforms of LANA, resul...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1516812113
更新日期:2016-02-23 00:00:00
abstract::MAP kinase-interacting kinase 1 and 2 (Mnk1 and Mnk2) are protein-serine/threonine kinases that are activated by ERK or p38 and phosphorylate eIF4E, which is involved in cap-dependent translation initiation. However, Mnk1/2 double knockout (Mnk-DKO) mice show normal cell growth and development despite an absence of eI...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1008136107
更新日期:2010-08-10 00:00:00
abstract::A glucose-responsive "closed-loop" insulin delivery system mimicking the function of pancreatic cells has tremendous potential to improve quality of life and health in diabetics. Here, we report a novel glucose-responsive insulin delivery device using a painless microneedle-array patch ("smart insulin patch") containi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1505405112
更新日期:2015-07-07 00:00:00
abstract::A series of anti-human placental uracil DNA glycosylase monoclonal antibodies was used to screen a human placental cDNA library in phage lambda gt11. Twenty-seven immunopositive plaques were detected and purified. One clone containing a 1.2-kilobase (kb) human cDNA insert was chosen for further study by insertion into...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.22.8693
更新日期:1989-11-01 00:00:00
abstract::Zea mays plasma membrane intrinsic proteins (ZmPIPs) fall into two groups, ZmPIP1s and ZmPIP2s, that exhibit different water channel activities when expressed in Xenopus oocytes. ZmPIP1s are inactive, whereas ZmPIP2s induce a marked increase in the membrane osmotic water permeability coefficient, P(f). We previously s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0701180104
更新日期:2007-07-24 00:00:00
abstract::Lithium ion at concentrations between 2 and 20 mM simulated the stimulatory effects of insulin on the uptake of alpha-aminoisobutyric acid, synthesis of RNA and DNA, and cell multiplication in mouse mammary gland explants cultured in a chemically defined synthetic medium. Other monovalent cations were virtually ineffe...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.6.2823
更新日期:1979-06-01 00:00:00
abstract::The mammalian AML/CBFalpha runt domain (RD) transcription factors regulate hematopoiesis and osteoblast differentiation. Like their Drosophila counterparts, most mammalian RD proteins terminate in a common pentapeptide, VWRPY, which serves to recruit the corepressor Groucho (Gro). Using a yeast two-hybrid assay, in vi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.20.11590
更新日期:1998-09-29 00:00:00
abstract::Network theory provides a powerful tool for the representation and analysis of complex systems of interacting agents. Here, we investigate the U.S. House of Representatives network of committees and subcommittees, with committees connected according to "interlocks," or common membership. Analysis of this network revea...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0500191102
更新日期:2005-05-17 00:00:00