Abstract:
:Binding of carbon monoxide and oxygen to sterically protected heme model compounds (basket-handle porphyrins) was investigated in liquid toluene at temperatures from 180 to 300 K by laser flash photolysis. Only a single exponential rebinding process from the solvent could be seen in the time range of 20 nsec to milliseconds. The fraction of ligands that initially escaped into the solvent decreased when the temperature was lowered, and the Arrhenius plots for the rebinding rate coefficients were found to deviate significantly from linearity. These findings suggest that protected heme model compounds might react according to a double energy-barrier scheme. In contrast, the reaction of an unprotected porphyrin can be described by a single energy barrier.
journal_name
Proc Natl Acad Sci U S Aauthors
Tetreau C,Lavalette D,Momenteau M,Lhoste JMdoi
10.1073/pnas.84.8.2267subject
Has Abstractpub_date
1987-04-01 00:00:00pages
2267-71issue
8eissn
0027-8424issn
1091-6490journal_volume
84pub_type
杂志文章abstract::The effect of metabolic depletion on the maturation-associated loss of membrane functions has been studied by using sheep reticulocytes incubated in vitro at 37 degrees C for periods up to 41 hr. ATP was either maintained with glucose, adenosine plus inosine, or depleted with 2-deoxyglucose plus arsenate. Two membrane...
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.80.16.4978
更新日期:1983-08-01 00:00:00
abstract::Language and analytic processing are currently thought to be represented in the left hemisphere, whereas spatial and holistic processing would involve primarily the right hemisphere in man. An experimental paradigm for engaging the nonlanguage hemisphere (generally the right) is described. This involves active touch e...
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.74.9.4037
更新日期:1977-09-01 00:00:00
abstract::Leukosialin (also known as Ly48, CD43, and sialophorin) is a major cell surface sialoglycoprotein found on a variety of hematopoietically derived cells. The precise function of this molecule is poorly understood but it has been implicated in cell proliferation and intercellular adhesion. We developed a transgenic mous...
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.92.2.626
更新日期:1995-01-17 00:00:00
abstract::RNA interference (RNAi) is being used to develop methods to control pests and disease vectors. RNAi is robust and systemic in coleopteran insects but is quite variable in other insects. The determinants of efficient RNAi in coleopterans, as well as its potential mechanisms of resistance, are not known. RNAi screen ide...
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.1809381115
更新日期:2018-08-14 00:00:00
abstract::The use of carbon dioxide as a renewable and environmentally friendly source of carbon in organic synthesis is a highly attractive approach, but its real world applications remain a great challenge. The major obstacles for commercialization of most current protocols are their low catalytic performances, harsh reaction...
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.1010962107
更新日期:2010-11-23 00:00:00
abstract::Rabbit corneas denuded of their endothelium were coated with bovine corneal endothelial cells (from steers) previously maintained in tissue culture for short (20 generations) or prolonged (200 generations) periods. When grafted back into female rabbits, the corneal buttons remained clear and showed no edema. In contra...
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.76.1.464
更新日期:1979-01-01 00:00:00
abstract::The POT1 (protection of telomeres 1) protein binds the ssDNA overhangs at the ends of chromosomes in diverse eukaryotes. POT1 is essential for chromosome end-protection, as best demonstrated in fission yeast. In human cells, hPOT1 is also involved in telomere-length regulation. We now show that telomeric oligonucleoti...
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.0504744102
更新日期:2005-08-02 00:00:00
abstract::Heme oxygenase (decyclizing) [heme,hydrogen-donor:oxygen oxidoreductase (alpha-methene-oxidizing, hydroxylating), EC 1.14.99.3] is greatly induced in the kidney by the administration of nickel or tin. Manganese, when administered simultaneously with nickel or tin in an equimolar amount, substantially inhibited the ind...
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.76.10.5331
更新日期:1979-10-01 00:00:00
abstract::A near-full-length casbene synthase cDNA clone, pCS7, was isolated by using a partial cDNA clone, pCS4, to probe a lambda gt10 library constructed from poly(A)+ RNA from elicited castor bean seedlings. The cDNA insert had a length of 1983 bases with a polyadenylate tail of 19 bases. Translation of the cDNA sequence re...
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.91.18.8497
更新日期:1994-08-30 00:00:00
abstract::Human gene MAGE-1 encodes tumor-specific antigens that are recognized on melanoma cells by autologous cytolytic T lymphocytes. This gene is expressed in a significant proportion of tumors of various histological types, but not in normal tissues except male germ-line cells. We reported previously that reporter genes dr...
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.93.14.7149
更新日期:1996-07-09 00:00:00
abstract::Using a diverse collection of small molecules we recently found that compound sets from different sources (commercial; academic; natural) have different protein-binding behaviors, and these behaviors correlate with trends in stereochemical complexity for these compound sets. These results lend insight into structural ...
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.1015024108
更新日期:2011-04-26 00:00:00
abstract::Genetic evidence indicates that the PrlA (SecY) protein of Escherichia coli functions as a membrane integrated signal sequence receptor in protein "export"--i.e., in protein translocation across (or integration into) the plasma membrane. We have raised antibodies in rabbits against two synthetic peptides representing ...
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.86.6.1895
更新日期:1989-03-01 00:00:00
abstract::Physical and biological systems are often involved with coupled processes of different time scales. In the system with electronic and atomic motions, for example, the interplay between the atomic motion along the same energy landscape and the electronic hopping between different landscapes is critical: the system beha...
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.1305604110
更新日期:2013-09-10 00:00:00
abstract::Harvey and Kirsten murine sarcoma viruses each encode a structurally and functionally related 21-kilodalton protein (p21), which is the transforming protein of each virus. Using probes from the 0.9-kilobase (kb) p21-coding region of each virus (called v-Ha-ras and v-Ki-ras, respectively), we have molecularly cloned fr...
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.79.16.4848
更新日期:1982-08-01 00:00:00
abstract::Young male baboons born in captivity were immunized with an attenuated, cryopreserved schistosomular vaccine derived from gamma-irradiated (50 krad) cercariae of the Puerto Rican strain of Schistosoma mansoni. Protection against a heterologous Kenyan strain of S. mansoni, after percutaneous infection, was assessed. Pa...
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.81.11.3552
更新日期:1984-06-01 00:00:00
abstract::Hydrogen bonds and their relative strengths in proteins are of importance for understanding protein structure and protein motions. The correct strength of such hydrogen bonds is experimentally known to vary greatly from approximately 5-6 kcal/mol for the isolated bond to approximately 0.5-1.5 kcal/mol for proteins 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.2133366100
更新日期:2003-10-28 00:00:00
abstract::Lateral inhibition is the ubiquitous strategy used by visual neurons for spatial resolution throughout the animal kingdom. It has been a puzzle whether lateral inputs in retinal bipolar cells are mediated by the horizontal cell (HC)-cone feedback synapse, by the HC-bipolar cell feedforward synapse, or by both. By bloc...
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.88.8.3310
更新日期:1991-04-15 00:00:00
abstract::Individual proteins can now often be modified with atomic precision, but there are still major obstacles to connecting proteins into larger assemblies. To direct protein assembly, ideally, peptide tags would be used, providing the minimal perturbation to protein function. However, binding to peptides is generally weak...
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.1315776111
更新日期:2014-04-01 00:00:00
abstract::Characterization and functional annotation of the large number of proteins predicted from genome sequencing projects poses a major scientific challenge. Whereas several proteomics techniques have been developed to quantify the abundance of proteins, these methods provide little information regarding protein function. ...
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.0501205102
更新日期:2005-04-05 00:00:00
abstract::Multiple independent mutations in neuroligin genes were identified in patients with familial autism, including the R451C substitution in neuroligin-3 (NL3). Previous studies showed that NL3(R451C) knock-in mice exhibited modestly impaired social behaviors, enhanced water maze learning abilities, and increased synaptic...
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.1111093108
更新日期:2011-08-16 00:00:00
abstract::An inversion loop seen in heteroduplex mapping of the DNA of mature Mu phage induced from a lysogen is observed also in defective lambda phage carrying one end of Mu. 14% of the DNA of Mu, including this region, designated the G loop, is shown to be to the right of all known genes in the prophage map. The inhomogeneou...
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.70.7.2153
更新日期:1973-07-01 00:00:00
abstract::The early steps in the biosynthesis of Taxol involve the cyclization of geranylgeranyl diphosphate to taxa-4(5),11(12)-diene followed by cytochrome P450-mediated hydroxylation at C5, acetylation of this intermediate, and a second cytochrome P450-dependent hydroxylation at C10 to yield taxadien-5 alpha-acetoxy-10 beta-...
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.98.4.1501
更新日期:2001-02-13 00:00:00
abstract::Smooth muscle cells (SMCs) have been shown to migrate in response to insulin-like growth factor I (IGF-I). However, the mechanism mediating this response has not been determined. The migration rates of porcine and human vascular SMCs were assessed in a monolayer wounding assay. IGF-I and IGF-II induced increases of 14...
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.93.6.2482
更新日期:1996-03-19 00:00:00
abstract::The utility of adenovirus (Ad) vectors for gene transduction can be limited by receptor specificity. We developed a gene-delivery vehicle in which the potent Ad5 vector was genetically reengineered to display the mucosal-targeting sigma1 protein of reovirus type 3 Dearing (T3D). A sigma1 construct containing all but a...
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.0400542101
更新日期:2004-04-20 00:00:00
abstract::Treatment of Madin-Darby bovine kidney (MDBK) cells with human interferon (IFN)-alpha 2 at 37 degrees C results in a dose-dependent inhibition of cell growth and a reduction of the subsequent binding of 125I-labeled epidermal growth factor (EGF) at 4 degrees C. Human IFN-beta and -gamma, which exhibit little antiviral...
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.83.21.8226
更新日期:1986-11-01 00:00:00
abstract::The management of harmful species, including invasive species, pests, parasites, and diseases, is a major global challenge. Harmful species cause severe damage to ecosystems, biodiversity, agriculture, and human health. In particular, managing harmful species often requires cooperation among multiple agents, such as l...
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.1917028117
更新日期:2020-05-12 00:00:00
abstract::Epidermal growth factor (EGF) stimulates membrane protein phosphorylation in a human cell line, A-431. The known hepatic mitogenic action of EGF and the reduction in EGF receptor number that occurs during liver regeneration led us to study whether EGF-dependent protein kinase activity was present in rat liver and whet...
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.79.3.776
更新日期:1982-02-01 00:00:00
abstract::ADP activates a family of cell surface receptors that modulate signaling pathways in a broad range of cells. ADP receptor antagonists are widely used to treat cardiovascular disease states. These studies identify a critical role for the stable reactive oxygen species hydrogen peroxide (H2O2) in mediating cellular 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.1320854111
更新日期:2014-03-04 00:00:00
abstract::Hypnotic analgesia in some respects resembles opiate analgesia. We tested the hypothesis that some features of hypnotic analgesia are mediated through neuronal pathways activating specific opiate receptors in brain. The opiate antagonist naloxone had no effect on hypnotic analgesia in three subjects. Thus, the hypothe...
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.72.6.2041
更新日期:1975-06-01 00:00:00
abstract::The switch from fetal to adult hemoglobin expression is regulated in many mammalian species by a developmental clock-like mechanism and determined by the gestational age of the fetus. Prolonging fetal globin gene expression is of considerable interest for therapeutic potential in diseases caused by abnormal beta-globi...
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.85.22.8540
更新日期:1988-11-01 00:00:00