Abstract:
:Using isotopic tracer methods, we have shown that dihydrolipoic acid (2,3-thioctic acid) acylates the distal oxygen of ferrous oxygenated Pseudomonas cytochrome P-450, forming a transient acyl peroxide intermediate that facilitates oxygen-oxygen bond cleavage. Single-turnover studies with 18O2 indicate one oxygen-18 atom incorporated into the carboxylate group of lipoic acid for each oxygen-18 inserted into the substrate, camphor, forming the product, exo-5-hydroxycamphor. Such a branching ratio for label indicates that water is initially released from an unlageled position and illustrates that the general P-450 mixed-function oxidase stoichiometry generates H218O from 18O2 only after multiple-turnover equilibration with the acylating carboxylate oxygen. Formation of an acyl peroxide state is a natural intermediate in peracid, "oxene", or radical mechanisms for methylene carbone oxygenation.
journal_name
Proc Natl Acad Sci U S Aauthors
Sligar SG,Kennedy KA,Pearson DCdoi
10.1073/pnas.77.3.1240subject
Has Abstractpub_date
1980-03-01 00:00:00pages
1240-4issue
3eissn
0027-8424issn
1091-6490journal_volume
77pub_type
杂志文章abstract::Gamma-Glutamyl transpeptidase, which consists of two nonidentical subunits, is rapidly inactivated with respect to its transpeptidase and hydrolase activities by the gamma-glutamyl analogs 6-diazo-5-oxo-L-norleucine and L-azaserine. Inactivation, which is prevented by gamma-glutamyl substrates (but not by acceptor sub...
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.74.3.931
更新日期:1977-03-01 00:00:00
abstract::The ability of estrogens to stimulate the transcriptional activity of the estrogen receptor can be inhibited by a diverse range of estrogen antagonists. Here we show that the antiestrogen ICI 164,384, N-(n-butyl)-11-[3,17 beta-dihydroxy-estra-1,3,5(10)-trien-7 alpha-yl]N-methylundecanamide, rapidly reduces the levels ...
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.89.9.4037
更新日期:1992-05-01 00:00:00
abstract::The amount of information that can be stored in working memory is limited but may be improved with practice. The basis of improved efficiency at the level of neural activity is unknown. To investigate this question, we trained monkeys to perform a working memory task that required memory for multiple stimuli. Performa...
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.1817278116
更新日期:2019-04-02 00:00:00
abstract::Cytochrome c maturation in Escherichia coli requires the ccm operon, which encodes eight membrane proteins (CcmABCDEFGH). CcmE is a periplasmic heme chaperone that binds heme covalently and transfers it onto apocytochrome c in the presence of CcmF, CcmG, and CcmH. In this work we addressed the functions of the ccmABCD...
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.96.11.6462
更新日期:1999-05-25 00:00:00
abstract::To examine the influence of interferon gamma (IFN-gamma) on tumorigenicity, we established constitutively IFN-gamma-producing cell lines from a malignant mouse neuroblastoma, C1300, by retroviral transfer of a mouse IFN-gamma cDNA. The gene-transferred cells generally showed an enhanced high-level expression of the ma...
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.86.23.9456
更新日期:1989-12-01 00:00:00
abstract::How cells achieve their final sizes is a pervasive biological question. One strategy to increase cell size is for the cell to amplify its chromosomal DNA content through endoreduplication cycles. Although endoreduplication is widespread in eukaryotes, we know very little about its molecular mechanisms. Successful prog...
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.0505883102
更新日期:2005-12-20 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.1605512113
更新日期:2016-05-17 00:00:00
abstract::The thylakoid compartments of plant chloroplasts are a vital destination for copper. Copper is needed to form holo-plastocyanin, which must shuttle electrons between photosystems to convert light into biologically useful chemical energy. Copper can bind tightly to proteins, so it has been hypothesized that copper part...
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.0600142103
更新日期:2006-05-30 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.88.16.7289
更新日期:1991-08-15 00:00:00
abstract::A major function of innate immune receptors is to recognize pathogen-associated molecular patterns and then evoke immune responses appropriate to the nature of the invading pathogen(s). Because innate immune cells express various types of these receptors, distinct combinations of signaling pathways are activated in 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.1320145110
更新日期:2013-12-03 00:00:00
abstract::The gene encoding latent-infection membrane protein 1 (LMP1) was specifically mutated in Epstein-Barr virus (EBV) recombinants by inserting a nonsense linker after codon 9 or codon 84 or into an intron 186 bp 3' to the latter insertion site. EBV recombinants with the LMP1 intron mutation were wild type for LMP1 expres...
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.90.19.9150
更新日期:1993-10-01 00:00:00
abstract::In mammals and insects, pheromones strongly influence social behaviors such as aggression and mate recognition. In Drosophila melanogaster, pheromones in the form of cuticular hydrocarbons play prominent roles in courtship. GC/MS is the primary analytical tool currently used to study Drosophila cuticular hydrocarbons....
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.0802692105
更新日期:2008-05-20 00:00:00
abstract::We prove that the property of excision in algebraic K-theory is for a Q-algebra A equivalent to the H-unitality of the latter. Our excision theorem, in particular, implies Karoubi's conjecture on the equality of algebraic and topological K-theory groups of stable C*-algebras. It also allows us to identify the algebrai...
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.87.24.9582
更新日期:1990-12-15 00:00:00
abstract::Sirtuin 2 (SIRT2) is a sirtuin family deacetylase that directs acetylome signaling, protects genome integrity, and is a murine tumor suppressor. We show that SIRT2 directs replication stress responses by regulating the activity of cyclin-dependent kinase 9 (CDK9), a protein required for recovery from replication arres...
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.1301463110
更新日期:2013-08-13 00:00:00
abstract::For a distribution F on R(p) and a point x in R(p) the simplicial depth D(x), which is the probability that x be inside a random simplex whose vertices are p + 1 independent observations from F, is introduced. D(x) can be viewed as a measure of depth of the point x relative to F, and its empirical version gives rise 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.85.6.1732
更新日期:1988-03-01 00:00:00
abstract::We report here the biologically active conformation of acetylcholine when bound to the high-affinity state of the receptor from Torpedo californica. The acetylcholine conformation was determined in the free and bound states by proton NMR two-dimensional nuclear Overhauser effects. In agreement with x-ray crystallograp...
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.85.18.6721
更新日期:1988-09-01 00:00:00
abstract::The nonclassical MHC class I-related (MHC-I) molecule HFE controls cellular iron homeostasis by a mechanism that has not been fully elucidated. We examined the regulation of HFE by K5, the E3 ubiquitin ligase encoded by Kaposi's sarcoma-associated herpesvirus (KSHV/HHV8), that is known to down-regulate classical MHC-I...
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.1003421107
更新日期:2010-09-14 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
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更新日期:2003-05-13 00:00:00
abstract::The molecular nature of the cell surface-cytoskeleton interaction in microvilli isolated from ascites 13762 rat mammary adenocarcinoma sublines with immobile (MAT-C1) and mobile (MAT-B1) receptors was investigated by extraction and fractionation studies on the microvillar membranes. Extraction of membranes from MAT-C1...
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.80.2.430
更新日期:1983-01-01 00:00:00
abstract::Tetracycline resistance encoded by four genetically different determinants residing on plasmids in Escherichia coli was shown to be associated in each case with an energy-dependent decrease in accumulation of the antibiotic in whole cells in which resistance had been induced. The different class determinants examined ...
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.77.7.3974
更新日期:1980-07-01 00:00:00
abstract::Histones play a crucial role in the organization of DNA in the nucleus, but their presence can prevent interactions with DNA binding proteins responsible for repair of DNA damage. Uracil is an abundant mutagenic lesion recognized by uracil DNA glycosylase (UDG) in the first step of base excision repair (BER). In nucle...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2010-03-09 00:00:00
abstract::The interaction between DNA polymerases and sliding clamp proteins confers processivity in DNA synthesis. This interaction is critical for most DNA replication machines from viruses and prokaryotes to higher eukaryotes. The clamp proteins also participate in a variety of dynamic and competing protein-protein interacti...
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.191384398
更新日期:2001-09-25 00:00:00
abstract::A highly purified fraction obtained from scrapie (263-K strain)-infected hamsters' brains by an alternative procedure without proteinase K treatment contained a protease-resistant form of the scrapie precursor protein (PrPSc) and infectivity of 9.9 +/- 0.7 log LD50/ml. Polyclonal antibodies produced against hamster sc...
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.87.16.6373
更新日期:1990-08-01 00:00:00
abstract::Many approaches to the origin of life focus on how the molecules found in biology might be made in the absence of biological processes, from the simplest plausible starting materials. Another approach could be to view the emergence of the chemistry of biology as process whereby the environment effectively directs "pri...
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.1813987116
更新日期:2019-03-19 00:00:00
abstract::The activity of leukotriene A4 (LTA4) synthase in crude human leukocyte homogenates was found to have a similar requirement for Ca2+ and ATP as had been noted previously for 5-lipoxygenase activity. Purification of the 5-lipoxygenase using ammonium sulfate fractionation, AcA 44 gel-filtration chromatography, and HPLC ...
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.83.4.857
更新日期:1986-02-01 00:00:00
abstract::The ASCAPE agent-based modeling environment greatly eases the task of designing and investigating agent-based models. However, effective design can still require a relatively deep knowledge of programming and agent-based modeling. This issue has almost certainly slowed the adoption of agent-based modeling approaches t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:2002-05-14 00:00:00
abstract::The expanding behavioral repertoire of the developing brain during childhood and adolescence is shaped by complex brain-environment interactions and flavored by unique life experiences. The transition into young adulthood offers opportunities for adaptation and growth but also increased susceptibility to 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.2001517117
更新日期:2020-06-02 00:00:00
abstract::We have measured the oxygen concentration in the body water of murine FSa and NFSa fibrosarcomas using a new method for quantitative oxygen concentration determination deep in the tissues of a living animal. The measurement uses unusually low-frequency electron paramagnetic spectroscopy sensitive to substrate 7 cm dee...
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.91.26.13047
更新日期:1994-12-20 00:00:00
abstract::The HIV type 1 (HIV-1) virion infectivity factor (Vif) protein blocks the action of the host defense factor APOBEC3G in human cells, thereby allowing release of infectious virions, but fails to inhibit similar APOBEC3G proteins present in some simian cells. Conversely, the Vif protein encoded by the African green monk...
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.0307713101
更新日期:2004-03-16 00:00:00
abstract::Filtration through the kidney eliminates toxins, manages electrolyte balance, and controls water homeostasis. Reabsorption of water from the luminal fluid of the nephron occurs through aquaporin-2 (AQP2) water pores in principal cells that line the kidney-collecting duct. This vital process is impeded by formation 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.1607745113
更新日期:2016-07-26 00:00:00