Abstract:
:The effect of fluctuations in rate constants on the kinetic behavior of cyclic reacting systems, caused by a fluctuating external parameter, is studied. It is shown (i) that the stochastic properties of the system can be analyzed analytically by using the usual master equation approach when the external parameter is fluctuating with discrete square pulses and (ii) that the system is equivalent to an expanded chemical kinetic system with no fluctuation in rate constants. When applied to a linear four-state cyclic enzyme system, the formalism can be used to prove analytically the finding that an enzyme can extract the free energy from an externally applied fluctuating membrane potential and perform active free energy transduction. The formalism also can be used to assess the asymmetry constraints imposed on the values of the rate constants in order for the model to work.
journal_name
Proc Natl Acad Sci U S Aauthors
Chen YDdoi
10.1073/pnas.84.3.729subject
Has Abstractpub_date
1987-02-01 00:00:00pages
729-33issue
3eissn
0027-8424issn
1091-6490journal_volume
84pub_type
杂志文章abstract::We report here on the isolation and characterization of a serotonin (5HT) transporter from Drosophila melanogaster. A 3.1-kb complementary DNA clone (dSERT) was found to encode a protein of 622 amino acid residues with a predicted molecular mass of approximately 69 kDa and a putative transmembrane topology characteris...
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.91.11.5158
更新日期:1994-05-24 00:00:00
abstract::Extensive studies have detailed the molecular regulation of individual components of the hemostatic system, including platelets, coagulation factors, and regulatory proteins. Questions remain, however, about how these elements are integrated at the systems level within a rapidly changing physical environment. To answe...
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.1813642116
更新日期:2019-02-05 00:00:00
abstract::1,N(6)-Ethenoadenosine triphosphate (epsilon-ATP) has been found to be inactive as a substrate for firefly luciferase. However, chemically synthesized luciferyl-epsilonAMP is oxidized by luciferase and light is emitted. The color of the light is red in contrast to the normal yellow-green observed with luciferyladenyla...
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.70.6.1664
更新日期:1973-06-01 00:00:00
abstract::Duchenne muscular dystrophy (DMD) is a lethal genetic disorder caused by an absence of the dystrophin protein in bodywide muscles, including the heart. Cardiomyopathy is a leading cause of death in DMD. Exon skipping via synthetic phosphorodiamidate morpholino oligomers (PMOs) represents one of the most promising ther...
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.1613203114
更新日期:2017-04-18 00:00:00
abstract::The biosynthesis of fibronectin during the in vivo development of matrix-induced endochondral bone was investigated by using [35S]methionine in rats. The dmineralized bone matrix that was implanted subcutaneously to induce local bone formation bound circulating fibronectin. This may be an important initial requirement...
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.77.4.2074
更新日期:1980-04-01 00:00:00
abstract::Double fertilization is a key innovation for the evolutionary success of angiosperms by which the two fertilized female gametes, the egg cell and central cell, generate the embryo and endosperm, respectively. The female gametophyte (embryo sac) enclosed in the sporophyte is derived from a one-celled haploid cell linea...
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.1909465117
更新日期:2020-03-17 00:00:00
abstract::Brain function depends on adaptive self-organization of large-scale neural assemblies, but little is known about quantitative network parameters governing these processes in humans. Here, we describe the topology and synchronizability of frequency-specific brain functional networks using wavelet decomposition of magne...
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.0606005103
更新日期:2006-12-19 00:00:00
abstract::Although soft devices (grippers, actuators, and elementary robots) are rapidly becoming an integral part of the broad field of robotics, autonomy for completely soft devices has only begun to be developed. Adaptation of conventional systems of control to soft devices requires hard valves and electronic controls. This ...
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.1820672116
更新日期:2019-04-16 00:00:00
abstract::A 38-base-pair region required for normal CYC1 mRNA 3' end formation in Saccharomyces cerevisiae was shown to be necessary for the termination of transcription in vivo by examining the stability of CEN3 plasmids. CEN3 plasmids were stably maintained during vegetative growth, unless a GAL1 transcript impinged on the CE...
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.86.21.8348
更新日期:1989-11-01 00:00:00
abstract::Food is a powerful entrainment cue for circadian clocks in peripheral tissues, and changes in the composition of nutrients have been demonstrated to metabolically reprogram peripheral clocks. However, how food challenges may influence circadian metabolism of the master clock in the suprachiasmatic nucleus (SCN) or in ...
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.2016589117
更新日期:2020-11-24 00:00:00
abstract::IscR (iron-sulfur cluster regulator) is encoded by an ORF located immediately upstream of genes coding for the Escherichia coli Fe-S cluster assembly proteins, IscS, IscU, and IscA. IscR shares amino acid similarity with MarA, a member of the MarA/SoxS/Rob family of transcription factors. In this study, we found 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.251550898
更新日期:2001-12-18 00:00:00
abstract::As 3D culture has become central to investigation of tissue biology, mammary epithelial organoids have emerged as powerful tools for investigation of epithelial cell polarization and carcinogenesis. However, most current protocols start from single cells suspended in Matrigel, which can also restrict cell differentiat...
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.1702372116
更新日期:2019-06-04 00:00:00
abstract::It is widely accepted that modern humans originated in sub-Saharan Africa approximately 150-200 thousand years ago (ka), but their route of dispersal across the currently hyperarid Sahara remains controversial. Given that the first modern humans north of the Sahara are found in the Levant approximately 120-90 ka, nort...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.0804472105
更新日期:2008-10-28 00:00:00
abstract::The circadian clock in eukaryotes controls transcriptional and posttranscriptional events, including regulation of the levels and phosphorylation state of translation factors. However, the mechanisms underlying clock control of translation initiation, and the impact of this potential regulation on rhythmic protein syn...
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.1918459117
更新日期:2020-05-19 00:00:00
abstract::Cdc10-dependent transcript 1 (Cdt1) is an essential DNA replication protein whose accumulation at the end of the cell cycle promotes the formation of pre-replicative complexes and replication in the next cell cycle. Geminin is thought to be involved in licensing replication by promoting the accumulation of Cdt1 in mit...
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.1310677110
更新日期:2013-07-23 00:00:00
abstract::Visual information is conveyed from the eye to the brain by distinct types of retinal ganglion cells (RGCs). It is largely unknown how RGCs acquire their defining morphological and physiological features and connect to upstream and downstream synaptic partners. The three Brn3/Pou4f transcription factors (TFs) particip...
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.1618551114
更新日期:2017-05-16 00:00:00
abstract::A monoclonal antibody has been developed that recognizes a mouse lymphocyte antigen, Ly-23, that is controlled by an H-3 histocompatibility complex-linked gene on the second chromosome. Competitive binding experiments demonstrate that this antigen is distinct from the polymorphic beta 2-microglobulin antigen, which al...
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.80.21.6620
更新日期:1983-11-01 00:00:00
abstract::Food avoidance learning in the mollusc Pleurobranchaea entails reduction in the responsiveness of key brain interneurons in the feeding neural circuitry, the paracerebral feeding command interneurons (PCNs), to the neurotransmitter acetylcholine (AcCho). Food stimuli applied to the oral veil of an untrained animal dep...
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.83.12.4556
更新日期:1986-06-01 00:00:00
abstract::RS67333 is a partial serotonin subtype 4 receptor (5-HT4R) agonist that has been widely studied for its procognitive effect. More recently, it has been shown that its ability to promote the nonamyloidogenic cleavage of the precursor of the neurotoxic amyloid-β peptide leads to the secretion of the neurotrophic protein...
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.1410315111
更新日期:2014-09-09 00:00:00
abstract::Junctions that mediate excitation-contraction (e-c) coupling are formed between the sarcoplasmic reticulum (SR) and either the surface membrane or the transverse (T) tubules in normal skeletal muscle. Two structural components of the junctions, the feet of the SR and the tetrads of T tubules, have been identified resp...
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.92.8.3381
更新日期:1995-04-11 00:00:00
abstract::Current drug discovery efforts focus on identifying lead compounds acting on a molecular target associated with an established pathological state. Concerted molecular changes that occur in specific cell types during disease progression have generally not been identified. Here, we used constellation pharmacology to inv...
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.1922618117
更新日期:2020-10-20 00:00:00
abstract::The effect of tumor promoters on electrical coupling between human FL cells was investigated with a microelectrode technique. When a low concentration (100 ng/ml) of 12-O-tetradecanoylphorbol 13-acetate (TPA) was added to culture medium, only 6% of the cells showed electrical coupling after 5 hr, whereas in control me...
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.78.9.5628
更新日期:1981-09-01 00:00:00
abstract::Mutations in profilin 1 (PFN1) are associated with amyotrophic lateral sclerosis (ALS); however, the pathological mechanism of PFN1 in this fatal disease is unknown. We demonstrate that ALS-linked mutations severely destabilize the native conformation of PFN1 in vitro and cause accelerated turnover of the PFN1 protein...
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.1424108112
更新日期:2015-06-30 00:00:00
abstract::Global supply chains play a critical role in many of the most pressing environmental stresses and social struggles identified by the United Nations' Sustainable Development Goals (SDGs). Responding to calls from the global community, companies are adopting a variety of voluntary practices to improve the environmental ...
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.1716695115
更新日期:2018-02-27 00:00:00
abstract::Colloidal particles with directional interactions are key in the realization of new colloidal materials with possibly unconventional phase behaviors. Here we exploit DNA self-assembly to produce bulk quantities of "DNA stars" with three or four sticky terminals, mimicking molecules with controlled limited valence. Sol...
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.1304632110
更新日期:2013-09-24 00:00:00
abstract::The tumor microenvironment restrains conventional T cell (Tconv) activation while facilitating the expansion of Tregs. Here we showed that Tregs' advantage in the tumor milieu relies on supplemental energetic routes involving lipid metabolism. In murine models, tumor-infiltrating Tregs displayed intracellular lipid ac...
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.1720113115
更新日期:2018-07-10 00:00:00
abstract::This paper provides transcendental and algebraic framework for the classification of identities expressing pi and other logarithms of algebraic numbers as rapidly convergent generalized hypergeometric series in rational parameters. Algebraic and arithmetic relations between values of p+1Fp hypergeometric functions and...
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.95.6.2744
更新日期:1998-03-17 00:00:00
abstract::Multiple cues, across multiple sensory modalities, are involved in mate choice in a wide range of animal taxa. This multiplicity leads to the prediction that, in adaptive radiations, sexual isolation results from divergence in multiple dimensions. However, difficulties in directly measuring preferences and detecting m...
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.1003537107
更新日期:2010-09-21 00:00:00
abstract::The interleukin 2 (IL-2) receptor (IL-2R) is a multisubunit receptor that includes three major IL-2 binding subunits, the IL-2R alpha, beta, and gamma chains. We have detected and analyzed cooperative interactions between the IL-2R alpha and beta chains (IL-2R alpha and IL-2R beta, respectively) in COS cells transfect...
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.91.8.3344
更新日期:1994-04-12 00:00:00
abstract::Dystrophic or ectopic mineral deposition occurs in many pathologic conditions, including atherosclerosis. Calcium mineral deposits that frequently accompany atherosclerosis are readily quantifiable radiographically, serve as a surrogate marker for the disease, and predict a higher risk of myocardial infarction and dea...
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.1932554100
更新日期:2003-09-30 00:00:00