Abstract:
:It was shown in an earlier paper how to connect, in principle, the biochemical states of a cross-bridge with the mechanics of muscular contraction, by the methods of statistical mechanics. The treatment applies to cross-bridges that are able to interact with only one actin site at a time. The present paper shows that it is a straightforward matter to extend the theory to groups of actin sites (three, five, etc.), say 55 A apart, as suggested by the work of Moore, H. E. Huxley, and DeRosier. The possibility of the cross-bridge attachment slipping between sites is included. This provides an alternative molecular interpretation of the model introduced by A. F. Huxley and Simmons. A second possible interpretation is also suggested: their discrete stable angles correspond to different biochemical (attached) states. The Huxley-Simmons analysis of an example is rederived and extended somewhat (x averaging), from the point of view of the present theory. Their qualitative conclusions are left unchanged by the x averaging, but significant quantitative effects are possible. Possible consequences of fast slipping in isotonic contraction are discussed in a preliminary way.
journal_name
Proc Natl Acad Sci U S Aauthors
Hill TLdoi
10.1073/pnas.70.10.2732subject
Has Abstractpub_date
1973-10-01 00:00:00pages
2732-6issue
10eissn
0027-8424issn
1091-6490journal_volume
70pub_type
杂志文章abstract::Junctional Adhesion Molecule-A (JAM-A) is a transmembrane adhesive protein expressed at endothelial junctions and in leukocytes. Here we report that JAM-A is required for the correct infiltration of polymorphonuclear leukocytes (PMN) into an inflamed peritoneum or in the heart upon ischemia-reperfusion injury. The def...
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.0500147102
更新日期:2005-07-26 00:00:00
abstract::To facilitate analysis of plant cell wall polysaccharide structure and composition, we cloned 74 genes encoding polysaccharide-degrading enzymes from Aspergillus nidulans, Aspergillus fumigatus, and Neurospora crassa and expressed the genes as secreted proteins with C-terminal Myc and 6x His tags. Most of the recombin...
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.0604632103
更新日期:2006-07-25 00:00:00
abstract::Biotin carboxylase [biotin-carboxyl-carrier-protein:carbon-dioxide ligase (ADP-forming), EC 6.3.4.14] is the enzyme mediating the first step of the acetyl-CoA carboxylase [acetyl-CoA:carbon-dioxide ligase (ADP-forming), EC 6.4.1.2] reaction. We screened an Escherichia coli DNA library and a DNA fragment carrying the b...
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.88.21.9730
更新日期:1991-11-01 00:00:00
abstract::Lipid rafts are important signaling platforms in T cells. Little is known about their properties in human CD8(+) T cells. We studied polarization of lipid rafts by digital immunofluorescence microscopy in primary human T cells, using beads coated with anti-CD3 and anti-CD28 mAbs (CD3/28 beads). Unlike CD4(+) T cells, ...
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.232058599
更新日期:2002-11-12 00:00:00
abstract::Salt and water secretion from intestinal epithelia requires enhancement of anion permeability across the apical membrane of Cl- secreting cells lining the crypt, the secretory gland of the intestine. Paneth cells located at the base of the small intestinal crypt release enteric defensins (cryptdins) apically into 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.94.16.8585
更新日期:1997-08-05 00:00:00
abstract::A 23-kilobase-pair segment of DNA containing the entire mouse serum albumin gene as well as 2.2 kilobase pairs of 5' and 4.3 kilobase pairs of 3' flanking sequences has been introduced into pSV2dhfr, a plasmid in which expression of the mouse dihydrofolate reductase cDNA is under the control of simian virus 40 sequenc...
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.82.3.765
更新日期:1985-02-01 00:00:00
abstract::Down-regulation of mitogenic signaling in mammalian cells relies in part on endosomal trafficking of activated receptors into lysosomes, where the receptors are degraded. These events are mediated by ubiquitination of the endosomal cargo and its consequent sorting into multivesicular bodies that form at the surfaces 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.0932599100
更新日期:2003-06-24 00:00:00
abstract::A major challenge in DNA microarray analysis is to effectively dissociate actual gene expression values from experimental noise. We report here a detailed noise analysis for oligonuleotide-based microarray experiments involving reverse transcription, generation of labeled cRNA (target) through in vitro transcription, ...
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.222164199
更新日期:2002-10-29 00:00:00
abstract::Proteopithecus sylviae is an archaic anthropoid from the late Eocene quarry L-41, Fayum Province, Egypt. The dentition of Proteopithecus is very primitive and does not closely resemble that of other, better known, primates from the Fayum (e.g., parapithecids and propliopithecids). The dental morphology, much of which ...
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.94.25.13760
更新日期:1997-12-09 00:00:00
abstract::During early postnatal development, sensory regions of the brain undergo periods of heightened plasticity which sculpt neural networks and lay the foundation for adult sensory perception. Such critical periods were also postulated for learning and memory but remain elusive and poorly understood. Here, we present evide...
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.1810125115
更新日期:2018-12-04 00:00:00
abstract::Antimicrobial peptides constitute an important component of the mammalian innate immune response. Several types of antimicrobial peptides, including the beta-defensins, are produced at epithelial surfaces in response to infectious threats. Here we show that a class of small molecules, including l-isoleucine and severa...
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.220424597
更新日期:2000-11-07 00:00:00
abstract::Whereas all mammals have one glutamate dehydrogenase gene (GLUD1), humans and apes carry an additional gene (GLUD2), which encodes an enzyme with distinct biochemical properties. We inserted a bacterial artificial chromosome containing the human GLUD2 gene into mice and analyzed the resulting changes in the transcript...
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.1519261113
更新日期:2016-05-10 00:00:00
abstract::Thebaine, an intermediate of morphine biosynthesis in the poppy plant, Papaver somniferum, was transformed to oripavine, codeine, and morphine by rat liver, kidney, and brain microsomes in the presence of an NADPH-generating system. The formation of morphine, codeine, and oripavine was identified by a specific RIA, HP...
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.85.4.1267
更新日期:1988-02-01 00:00:00
abstract::Phytochromes (phy) are red/far-red-absorbing photoreceptors that regulate the adaption of plant growth and development to changes in ambient light conditions. The nuclear transport of the phytochromes upon light activation is regarded as a key step in phytochrome signaling. Although nuclear import of phyA is regulated...
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.1120764109
更新日期:2012-04-10 00:00:00
abstract::Rapamycin is a potent immunosuppressant that blocks the G1/S transition in antigen-activated T cells and in yeast. The similar effects of rapamycin in animal cells and yeast suggest that the biochemical steps affected by rapamycin are conserved. Using a two-hybrid system we isolated mammalian clones that interact with...
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.91.26.12574
更新日期:1994-12-20 00:00:00
abstract::Balanced genetic polymorphism has been proposed as a source from which to infer population history complementary to that of neutral genetic polymorphism, because genetic polymorphism maintained by balancing selection permits inferences about population size over much longer spans of time. However, empirical data for b...
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.96.1.168
更新日期:1999-01-05 00:00:00
abstract::The nucleosomal repeat lengths of bulk chromatin and the chromatin of transcriptionally active and inactive genes were analyzed in two mouse cell lines and adult mouse spleens. The adult beta-globin gene exhibits a nucleosomal repeat length approximately 11 base pairs longer than (i) an inactive embryonic globin gene,...
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.80.18.5505
更新日期:1983-09-01 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
abstract::The nature of domestic cattle origins in Africa are unclear as archaeological data are relatively sparse. The earliest domesticates were humpless, or Bos taurus, in morphology and may have shared a common origin with the ancestors of European cattle in the Near East. Alternatively, local strains of the wild ox, the au...
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.93.10.5131
更新日期:1996-05-14 00:00:00
abstract::Genome-wide experiments often measure quantitative differences between treated and untreated cells to identify affected strains. For these studies, statistical models are typically used to determine significance cutoffs. We developed a method termed "CLIK" (Cutoff Linked to Interaction Knowledge) that overlays biologi...
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.1219582110
更新日期:2013-04-30 00:00:00
abstract::Conjugative relaxases are the proteins that initiate bacterial conjugation by a site-specific cleavage of the transferred DNA strand. In vitro, they show strand-transferase activity on single-stranded DNA, which suggests they may also be responsible for recircularization of the transferred DNA. In this work, we show 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.0506081102
更新日期:2005-11-08 00:00:00
abstract::RecQ helicases are a widely conserved family of ATP-dependent motors with diverse roles in nearly every aspect of bacterial and eukaryotic genome maintenance. However, the physical mechanisms by which RecQ helicases recognize and process specific DNA replication and repair intermediates are largely unknown. Here, we 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.1417594112
更新日期:2015-04-07 00:00:00
abstract::Nogo isoforms (Nogo-A and -B) have been implicated in regulating neural and cardiovascular functions, such as cell spreading and chemotaxis. Unlike the loop domain (Nogo-66) found in all Nogo isoforms that can interact with a neural-specific Nogo-66 receptor, the receptor for the amino terminus of Nogo-B that mediates...
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.0602427103
更新日期:2006-07-18 00:00:00
abstract::Analysis of variations in the concentrations or structures of biomolecules (e.g., mRNAs, proteins, peptides, natural products) that occur either naturally or in response to environmental or genetic perturbations can provide important insight into complex biological processes. Many biological samples are mixtures 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.96.10.5372
更新日期:1999-05-11 00:00:00
abstract::We report the identification and cloning of a 28-kDa polypeptide (p28) in Tetrahymena macronuclei that shares several features with the well studied heterochromatin-associated protein HP1 from Drosophila. Notably, like HP1, p28 contains both a chromodomain and a chromoshadow domain. p28 also shares features with linke...
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.95.23.13624
更新日期:1998-11-10 00:00:00
abstract::We have investigated the role of cAMP in NO- and prostanoid-independent relaxations that are widely attributed to an endothelium-derived hyperpolarizing factor (EDHF). Under control conditions EDHF-type relaxations evoked by acetylcholine (ACh) in rabbit iliac arteries were transient, but in the presence of the cAMP 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.092089799
更新日期:2002-04-30 00:00:00
abstract::Accurate protein folding is essential for proper cellular and organismal function. In the cell, protein folding is carefully regulated; changes in folding homeostasis (proteostasis) can disrupt many cellular processes and have been implicated in various neurodegenerative diseases and other pathologies. For many 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.1610272113
更新日期:2016-11-22 00:00:00
abstract::During organogenesis, the final size of mature cell populations depends on their rates of differentiation and expansion. Because transient expression of Neurogenin3 (Neurog3) in progenitor cells in the developing pancreas initiates their differentiation to mature islet cells, we examined the role of Neurog3 in cell cy...
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.1004842108
更新日期:2011-01-04 00:00:00
abstract::A general repressor extensively studied in vitro is the human Dr1/DRAP1 heterodimeric complex. To elucidate the function of Dr1 and DRAP1 in vivo, the yeast Saccharomyces cerevisiae Dr1/DRAP1 repressor complex was identified. The repressor complex is encoded by two essential genes, designated YDR1 and BUR6. The inviab...
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.94.3.820
更新日期:1997-02-04 00:00:00
abstract::Based on transfection into cells in culture or natural transduction into retroviruses, proto-ras genes seem to derive transforming function either from heterologous promoters or from point mutations. Here we ask how such different events could achieve the same results. To identify homologous regulatory elements, about...
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.88.6.2217
更新日期:1991-03-15 00:00:00