Abstract:
:The global configuration of individual, surface-adsorbed molecules of the giant muscle protein titin, labeled with rhodamine conjugates, was followed with confocal microscopy. Fluorescence-emission intensity was reduced because of self-quenching caused by the close spacing between rhodamine dye molecules that formed dimers. In the presence of chemical denaturants, fluorescence intensity increased, reversibly, up to 5-fold in a fast reaction; the kinetics were followed at the single-molecule level. We show that dimers formed in a concentrated rhodamine solution dissociate when exposed to chemical denaturants. Furthermore, titin denaturation, followed by means of tryptophan fluorescence, is dominated by a slow reaction. Therefore, the rapid fluorescence change of the single molecules reflects the direct action of the denaturants on rhodamine dimers rather than the unfolding/refolding of the protein. Upon acidic denaturation, which we have shown not to dissociate rhodamine dimers, fluorescence intensity change was minimal, suggesting that dimers persist because the unfolded molecule has contracted into a small volume. The highly contractile nature of the acid-unfolded protein molecule derives from a significant increase in chain flexibility. We discuss the potential implications this finding could have for the passive mechanical behavior of striated muscle.
journal_name
Proc Natl Acad Sci U S Aauthors
Grama L,Somogyi B,Kellermayer MSdoi
10.1073/pnas.191494098keywords:
subject
Has Abstractpub_date
2001-12-04 00:00:00pages
14362-7issue
25eissn
0027-8424issn
1091-6490pii
191494098journal_volume
98pub_type
杂志文章abstract::A subpopulation of phenobarbital-induced cytochrome P-450 in rat liver has been shown to consist of four closely related forms of the enzyme that appeared to be strain-related. In the present study, polypeptides composing this family were analyzed by two-dimensional electrophoresis of hepatic microsomes from 64 indivi...
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.80.21.6542
更新日期:1983-11-01 00:00:00
abstract::A weakly nonlinear oscillator of natural frequency omega(0) and damping ratio delta is driven by an amplitude-modulated force of dimensionless amplitude epsilon, carrier frequency omega, and modulation frequency omega(1). Each of (omega - omega(0))/omega(0), omega(1)/omega(0), and delta is O(epsilon(2/3)) as epsilon -...
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.81.12.3919
更新日期:1984-06-01 00:00:00
abstract::A controversial topic in the recent climate modeling literature is the fashion in which metastable low-frequency regimes in the atmosphere occur despite nearly Gaussian statistics for these planetary waves. Here a simple 57-mode paradigm model for such metastable atmospheric regime behavior is introduced and analyzed ...
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.0602641103
更新日期:2006-05-30 00:00:00
abstract::The number of red blood cells is normally tightly regulated by a classic homeostatic mechanism based on oxygen sensing in the kidney. Decreased oxygen delivery resulting from anemia induces the production of erythropoietin, which increases red cell production and hence oxygen delivery. Investigations of erythropoietin...
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.0508423103
更新日期:2006-01-17 00:00:00
abstract::Genetic data in the mouse have shown that endothelin 3 (ET3) and its receptor B (ETRB) are essential for the development of two neural crest (NC) derivatives, the melanocytes and the enteric nervous system. We report here the effects of ET3 in vitro on the differentiation of quail trunk NC cells (NCC) in mass and clon...
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.95.24.14214
更新日期:1998-11-24 00:00:00
abstract::We have established a transformation system for Dictyostelium discoideum. The transformation vector contains the protein coding region of the Tn5 neomycin resistance gene fused to the proposed promoter of the Dictyostelium actin 8 gene; the vector also contains a sequence that acts as an autonomously replicating seque...
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.79.23.7356
更新日期:1982-12-01 00:00:00
abstract::The colligative properties of ATP and catecholamines demonstrated in vitro are thought to be responsible for the extraordinary accumulation of solutes inside chromaffin cell secretory vesicles, although this has yet to be demonstrated in living cells. Because functional cells cannot be deprived of ATP, we have knocked...
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.1600690113
更新日期:2016-07-12 00:00:00
abstract::We propose differential principal component analysis (dPCA) for analyzing multiple ChIP-sequencing datasets to identify differential protein-DNA interactions between two biological conditions. dPCA integrates unsupervised pattern discovery, dimension reduction, and statistical inference into a single framework. It use...
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.1204398110
更新日期:2013-04-23 00:00:00
abstract::The remarkable capacity of the adult olfactory epithelium (OE) to regenerate fully both neurosensory and nonneuronal cell types after severe epithelial injury depends on life-long persistence of two stem cell populations: the horizontal basal cells (HBCs), which are quiescent and held in reserve, and mitotically activ...
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.1701333114
更新日期:2017-07-11 00:00:00
abstract::The accumulation of metal ions and amyloid-β (Aβ) aggregates found in the brain of patients with Alzheimer's disease (AD) has been suggested to be involved in AD pathogenesis. To investigate metal-Aβ-associated pathways in AD, development of chemical tools to target metal-Aβ species is desired. Only a few efforts, how...
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.1006091107
更新日期:2010-12-21 00:00:00
abstract::Reactive oxygen species, the by-products of oxidative energy metabolism, are considered a main proximate cause of aging. Accordingly, overexpression of the enzyme Cu-Zn superoxide dismutase 1 (SOD1) can lengthen lifespan of Drosophila melanogaster in the laboratory. However, the role of SOD1 as a main determinant of 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.0400222101
更新日期:2004-03-09 00:00:00
abstract::Current issues pertaining to theoretical simulations of materials, with a focus on systems of nanometer-scale dimensions, are discussed. The use of atomistic simulations as high-resolution numerical experiments, enabling and guiding formulation and testing of analytic theoretical descriptions, is demonstrated through ...
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.0408038102
更新日期:2005-05-10 00:00:00
abstract::Assembly of nitrogenase FeMoco is one of the key processes in bioinorganic chemistry. NifB and NifEN are two essential elements immediately adjacent to each other along the biosynthetic pathway of FeMoco. Previously, an 8Fe-precursor of FeMoco was identified on NifEN; however, the identity of the biosynthetic intermed...
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.1102773108
更新日期:2011-05-24 00:00:00
abstract::Recombinant full-length CD4 expressed in Spodoptera frugiperda 9 cells with the baculovirus system was electroinserted in erythrocyte (RBC) membranes. Of the inserted CD4, 70% was "correctly" oriented as shown by fluorescence quenching experiments with fluorescein-labeled CD4. The inserted CD4 displayed the same epito...
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.88.10.4409
更新日期:1991-05-15 00:00:00
abstract::Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the pathogenesis of obesity-driven type 2 diabetes mellitus and associated cardiovascular complications. Here, we show that perturbation of caveolar microdomains leads to insulin resistance and concomitant up-regulation of PAI-1 in 3T3L1 adipocytes. ...
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.0405278101
更新日期:2004-12-07 00:00:00
abstract::A small number of facial expressions may be universal in that they are produced by the same basic affective states and recognized as such throughout the world. However, other aspects of emotionally expressive behavior vary widely across culture. Just why do they vary? We propose that some cultural differences in expre...
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.1413661112
更新日期:2015-05-12 00:00:00
abstract::In December of 2015, the international community pledged to limit global warming to below 2 °C above preindustrial (PI) to prevent dangerous climate change. However, to what extent, and for whom, is danger avoided if this ambitious target is realized? We address these questions by scrutinizing heat stress, because the...
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.1617526114
更新日期:2017-04-11 00:00:00
abstract::Recent sequencing efforts have led to estimates of human cytomegalovirus (HCMV) genome-wide intrahost diversity that rival those of persistent RNA viruses [Renzette N, Bhattacharjee B, Jensen JD, Gibson L, Kowalik TF (2011) PLoS Pathog 7:e1001344]. Here, we deep sequence HCMV genomes recovered from single and longitud...
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.1818130116
更新日期:2019-03-19 00:00:00
abstract::Patients with primary (AL) cardiac amyloidosis suffer from progressive cardiomyopathy with a median survival of less than 8 months and a 5-year survival of <10%. Contributing to this poor prognosis is the fact that these patients generally do not tolerate standard heart failure therapies. The molecular mechanisms unde...
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.0912263107
更新日期:2010-03-02 00:00:00
abstract::The presence of nerve growth factor (NGF) mRNA and protein in the rat central nervous system is documented. Blot-hybridization analysis showed an abundance of NGF mRNA in the hippocampus, cerebral cortex, and olfactory bulb. Enzyme immunoassay confirmed significant levels of a NGF-like protein in the hippocampus and c...
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.83.3.817
更新日期:1986-02-01 00:00:00
abstract::The importance of proper ion channel trafficking is underpinned by a number of channel-linked genetic diseases whose defect is associated with failure to reach the cell surface. Conceptually, it is reasonable to suggest that the function of ion channels depends critically on the precise subcellular localization and th...
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.0908207106
更新日期:2009-10-27 00:00:00
abstract::We demonstrate gene transfer into rat heart in vivo by the direct injection of plasmid DNA. Injection of gene constructs driven by retroviral and cellular promoters resulted in detectable levels of reporter gene activities. The cellular promoter and 5' flanking sequence (positions -613 to +32) were derived from the ra...
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.88.10.4138
更新日期:1991-05-15 00:00:00
abstract::Parts of the primary structure of the NAD-specific glutamate dehydrogenase [L-glutamate:NAD oxidoreductase (deaminating), EC 1.4.1.2] from Neurospora crassa are presented. Segments of the sequence representing 886 unique amino-acid residues have been determined; the largest contains 267 residues. There are only short ...
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.72.12.4891
更新日期:1975-12-01 00:00:00
abstract::Rapid antibody production in response to invading pathogens requires the dramatic expansion of pathogen-derived antigen-specific B lymphocyte populations. Whether B cell population dynamics are based on stochastic competition between competing cell fates, as in the development of competence by the bacterium Bacillus 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.1715639115
更新日期:2018-03-20 00:00:00
abstract::A diploid strain of yeast (Saccharomyces cerevisiae) was found to be heterozygous for two forms of the highly repetitious ribosomal DNA. These forms could be distinguished by the pattern of fragments produced after digestion with the site-specific restriction endonuclease EcoRI. The mode of inheritance of ribosomal DN...
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.74.11.5091
更新日期:1977-11-01 00:00:00
abstract::Single cortical neurons in the mammalian brain receive signals arising from multiple sensory input channels. Dendritic integration of these afferent signals is critical in determining the amplitude and time course of the neurons' output signals. As of yet, little is known about the spatial and temporal organization 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.1112355108
更新日期:2011-09-13 00:00:00
abstract::The main consequence of the Chernobyl accident has been an increase in papillary thyroid carcinomas (PTCs) in those exposed to radioactive fallout as young children. Our aim was to identify genomic alterations that are associated with exposure to radiation. We used array comparative genomic hybridization to analyze 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.1017137108
更新日期:2011-06-07 00:00:00
abstract::The transcription and processing of mitochondrial 21S rRNA in a petite strain of Saccharomyces cerevisiae has been examined by electron microscopic analysis of R-loop hybrids and by hybridization of labeled mitochondrial DNA probes to RNA transferred to diazobenzyloxymethyl paper. We have shown the presence of a large...
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.77.3.1417
更新日期:1980-03-01 00:00:00
abstract::MAD2 inhibits the anaphase-promoting complex when chromosomes are unattached to the mitotic spindle. It acts as a tumor suppressor gene because MAD2+/-cells enter anaphase early and display chromosome instability, leading to the formation of lung tumors in mice. Complete MAD2 inactivation has not been identified in hu...
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.0306069101
更新日期:2004-03-30 00:00:00
abstract::One of the most basic predictions of almost any model of crime is that individual time preferences matter. However, empirical evidence on this fundamental property is essentially nonexistent. To our knowledge, this paper provides the first pieces of evidence on the link between time discounting and crime. We use a uni...
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.1522445113
更新日期:2016-05-31 00:00:00