Abstract:
:Molecular dynamics simulations of the response to oscillating electric field elicited from an altitudinal dipolar molecular rotor mounted on the Au(111) surface and previously studied experimentally in static fields show unidirectional rotation in one of the three pairs of conformational enantiomers. The simulations are based on the universal force field and take into account electronic friction in the metal through its effect on the image charges. The rotor consists of two cobalt sandwich posts whose upper decks carry a biphenyl-like rotator with a dipole moment perpendicular to the rotation axle, mounted parallel to the surface. A phase diagram of rotor performance at 10 K as a function of field frequency and amplitude contains five unidirectional rotation regions: synchronous, half-synchronous (every other cycle skipped), quarter-synchronous (only indistinctly), asynchronous, and essentially no response. The nature of the subharmonic "single-molecule parametric oscillator" behavior is understood in mechanistic detail. Simulations at higher temperatures distinguish the thermal ("Brownian") and driven regimes of rotation, elucidated in terms of time-dependent potential energy surfaces for the rotation.
journal_name
Proc Natl Acad Sci U S Aauthors
Horinek D,Michl Jdoi
10.1073/pnas.0506183102keywords:
subject
Has Abstractpub_date
2005-10-04 00:00:00pages
14175-80issue
40eissn
0027-8424issn
1091-6490pii
0506183102journal_volume
102pub_type
杂志文章abstract::We have used oligonucleotide-directed mutagenesis to make a specific change in the beta-lactamase (EC 3.5.2.6) (ampicillin resistance) gene of the plasmid pBR322. Evidence suggests that the active site for this enzyme may include a serine-threonine dyad (residues 70 and 71). By priming in vitro DNA synthesis with a ch...
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.79.21.6409
更新日期:1982-11-01 00:00:00
abstract::Among the 15 extracellular domains of the mannose 6-phosphate/insulin-like growth factor-2 receptor (M6P/IGF2R), domain 11 has evolved a binding site for IGF2 to negatively regulate ligand bioavailability and mammalian growth. Despite the highly evolved structural loops of the IGF2:domain 11 binding site, affinity-enh...
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.1513023113
更新日期:2016-05-17 00:00:00
abstract::Specific antibodies against types I and III collagens and procollagens were used to localize these proteins in cultured human cells. These studies indicate that the same cell makes both proteins. No type III procollagen synthesis was observed in cells from two patients with two patients with the Ehlers-Danlos type IV ...
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.73.11.4037
更新日期:1976-11-01 00:00:00
abstract::The evolution of insect resistance to pesticides poses a continuing threat to agriculture and human health. While much is known about the proximate molecular and biochemical mechanisms that confer resistance, far less is known about the regulation of the specific genes/gene families involved, particularly by trans-act...
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.1913603117
更新日期:2020-05-12 00:00:00
abstract::Tobacco mosaic virus (TMV) was reconstituted from the RNA of a common strain (OM) and the protein of a watermelon strain of cucumber green mottle mosaic virus (CGMMV-W), which is a member of the tobamovirus group. In 0.25 M phosphate buffer at 25 degrees C, CGMMV-W protein existed mainly as 21S aggregates. When this p...
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.79.19.5833
更新日期:1982-10-01 00:00:00
abstract::Molecular dynamics simulations show that the desolvation rates of isotopes of Li(+), K(+), Rb(+), Ca(2+), Sr(2+), and Ba(2+) may have a relatively strong dependence on the metal cation mass. This inference is based on the observation that the exchange rate constant, k(wex), for water molecules in the first hydration 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.1208184109
更新日期:2012-11-13 00:00:00
abstract::The effects of systemic PD134308 [0.1-3 mg/kg; an antagonist of the cholecystokinin (CCK) type B receptor], morphine, and intrathecal (i.t.) galanin (GAL) on the excitability of the spinal nociceptive flexor reflex and in the hot plate test were examined in rats. PD134308 caused a weak naloxone-reversible depression 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.87.18.7105
更新日期:1990-09-01 00:00:00
abstract::The "UV footprinting" technique has been used to detect contacts between EcoRI endonuclease and its recognition sequence at single nucleotide resolution. Comparison of the UV-footprinting results to the published crystal structure of the EcoRI endonuclease-DNA complex allows us to determine how UV light detects protei...
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.85.17.6247
更新日期:1988-09-01 00:00:00
abstract::Relaxin is a member of the insulin family of polypeptides that is best known as a reproductive hormone. In an effort to elucidate the mechanism of action of relaxin we previously localized the specific binding sites of a 32P-labeled relaxin in the rat uterus and brain. These studies suggested that, in addition to its ...
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.89.6.2384
更新日期:1992-03-15 00:00:00
abstract::Class I gene products D, L, and R encoded by the D region of the H-2q haplotype were isolated by sequential immunoprecipitation from Nonidet P-40 extracts of B10.AKM murine spleen cells. Primary structural comparisons of these molecules were made by tryptic peptide map analyses and radiochemical amino acid sequence de...
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.81.8.2499
更新日期:1984-04-01 00:00:00
abstract::A definitive assay for microbiological and biochemical research on the biodegradation of lignin was developed using radioactive synthetic lignins specifically labeled in the side chains, aromatic rings or in the methoxyl groups. The [14C]lignins were prepared by oxidative polymerization with peroxidase and H2O2 Of spe...
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.72.7.2515
更新日期:1975-07-01 00:00:00
abstract::Are animals conscious? If so, when did consciousness evolve? We address these long-standing and essential questions using a modern neuroscientific approach that draws on diverse fields such as consciousness studies, evolutionary neurobiology, animal psychology, and anesthesiology. We propose that the stepwise emergenc...
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.1301188110
更新日期:2013-06-18 00:00:00
abstract::The heme-copper oxidases constitute a superfamily of terminal dioxygen-reducing enzymes located in the inner mitochondrial or in the bacterial cell membrane. The presence of a mechanistically important covalent bond between a histidine ligand of the copper ion (Cu(B)) in the active site and a generally conserved tyros...
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.0606254103
更新日期:2006-10-31 00:00:00
abstract::The beta-globin locus control region (LCR) consists of four erythroid-specific DNase I-hypersensitive sites, which are necessary for high-level expression of the beta-like globin genes in erythroid tissues. One of these sites, designated 5'HS-2, functions as an erythroid-specific enhancer element in transfection and t...
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.89.9.3899
更新日期:1992-05-01 00:00:00
abstract::Human sporadic Creutzfeldt-Jakob disease (sCJD), endemic sheep scrapie, and epidemic bovine spongiform encephalopathy (BSE) are caused by a related group of infectious agents. The new U.K. BSE agent spread to many species, including humans, and clarifying the origin, specificity, virulence, and diversity of these agen...
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.0905825106
更新日期:2009-08-11 00:00:00
abstract::Given the slow unfolding of what may become catastrophic changes to Earth's climate, many are understandably distraught by failures of public policy to rise to the magnitude of the challenge. Few in the science community would think to question the scientific response to the unfolding changes. However, is the science ...
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.1906691116
更新日期:2019-12-03 00:00:00
abstract::AAV is unique among eukaryotic viruses in the ability of its DNA to integrate preferentially into a specific region of the human genome. Understanding AAV integration may aid in developing gene therapy systems with predictable integration sites. Using a gel mobility-shift assay, we have identified a DNA sequence withi...
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.91.13.5808
更新日期:1994-06-21 00:00:00
abstract::beta-Adrenergic receptors on Friend erythroleukemic cells were identified by the use of 125I-labeled hydroxybenzylpindolol, a potent beta-adrenergic antagonist. Binding of this ligand was saturable and stereospecific. The relative orders of potency of isoproterenol, epinephrine, and norepinephrine to displace bound hy...
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.77.7.4065
更新日期:1980-07-01 00:00:00
abstract::Argonaute (Ago) proteins are the key component of the RNA-induced silencing complex and mediate RNA interference (RNAi) in association with small RNAs. Although overall the mechanism of RNAi is well understood, many molecular details of this complex process are not. Here we report about in-depth steady-state and, in p...
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.1217838110
更新日期:2013-10-29 00:00:00
abstract::While we have come to appreciate the architectural complexity of microbially synthesized secondary metabolites, far less attention has been paid to linking their structural features with possible modes of action. This is certainly the case with tropodithietic acid (TDA), a broad-spectrum antibiotic generated by marine...
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.1518034113
更新日期:2016-02-09 00:00:00
abstract::Neonatal ablation of the suprachiasmatic nucleus in the rat has two important consequences. First, the direct projection from the retina to the suprachiasmatic nucleus fails to develop and no other retinal projection to any hypothalamic nucleus is formed. Second, circadian rhythms in drinking and spontaneous locomotor...
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.75.12.6243
更新日期:1978-12-01 00:00:00
abstract::Filipin, digitonin, and saponin react with membrane cholesterol to produce unique membrane alterations (sterol-specific complexes) that are easily discernible in freeze-fracture replicas. We have treated both noninnervated and innervated Xenopus embryonic muscle cells in culture with these agents. Freeze-fracture of t...
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.78.2.1278
更新日期:1981-02-01 00:00:00
abstract::In Paramecium tetraurelia, cyclic nucleotides are important physiological second messengers that could regulate dynein mechanochemistry by phosphorylation. A 29-kDa polypeptide that is phosphorylated in a cAMP- and Ca(2+)-sensitive manner in permeabilized cells and isolated axonemes is the only significant phosphoryla...
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.88.18.7918
更新日期:1991-09-15 00:00:00
abstract::The second structure of a eukaryotic RNA polymerase II so far determined, that of the enzyme from the fission yeast Schizosaccharomyces pombe, is reported here. Comparison with the previous structure of the enzyme from the budding yeast Saccharomyces cerevisiae reveals differences in regions implicated in start site 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.0903361106
更新日期:2009-06-09 00:00:00
abstract::Paracoccidioidomycosis, a disease caused by Paracoccidioides brasiliensis, which is endemic to Latin America, is much more common in men than women, suggesting a role for hormonal factors. We recently showed that two other yeasts possess steroid binding proteins and postulated that these receptor-like molecules repres...
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.80.24.7659
更新日期:1983-12-01 00:00:00
abstract::E-Cadherin, a cell adhesion molecule, which plays a key role in maintaining the epithelial phenotype, is regarded as an invasion-suppressor gene in light of accumulating evidence from in vitro experiments and clinical observations. In an attempt to clarify the mechanism responsible for inactivation of this gene in car...
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.92.16.7416
更新日期:1995-08-01 00:00:00
abstract::Ca2+/calmodulin-dependent protein kinase II (CaM-KII) regulates numerous physiological functions, including neuronal synaptic plasticity through the phosphorylation of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors. To identify proteins that may interact with and modulate CaM-KII fun...
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.95.18.10890
更新日期:1998-09-01 00:00:00
abstract::MDM2 and MDMX are homologous proteins that bind to p53 and regulate its activity. Both contain three folded domains and ~70% intrinsically disordered regions. Previous detailed structural and biophysical studies have concentrated on the isolated folded domains. The N-terminal domains of both exhibit high affinity for ...
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.1317398110
更新日期:2013-10-29 00:00:00
abstract::Intrinsically disordered proteins (IDPs) are characterized by a lack of defined structure. Instead, they populate ensembles of rapidly interconverting conformations with marginal structural stabilities. Changes in solution conditions such as temperature and crowding agents consequently affect IDPs more than their fold...
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.1705105114
更新日期:2017-09-12 00:00:00
abstract::Mutations in the presenilin 1 (PS1) and presenilin 2 (PS2) genes increase the production of the highly amyloidogenic 42-residue form of amyloid beta-protein (Abeta42) in a variety of cell lines and transgenic mice. To elucidate the molecular mechanism of this effect, wild-type (wt) or mutant PS1 and PS2 genes were sta...
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.94.15.8208
更新日期:1997-07-22 00:00:00