Abstract:
:Incubation of rat calvaria for short times in the presence of a labeled amino acid revealed the existence of a collagen fraction (procollagen) that functions as a biosynthetic precursor of collagen. Procollagen contains an alpha1-like chain (pre-alpha1) that elutes earlier from CM-cellulose than does rat-bone alpha1 and has a molecular weight, estimated by acrylamide gel electrophoresis, of 120,000. A time-dependent conversion of pre-alpha1 to alpha1 was demonstrated by incubation of calvaria for periods varying from 9 to 60 min and by a pulse-chase experiment. Limited cleavage of procollagen with pepsin resulted in a molecule with a chain resembling alpha1 in chromatographic properties, molecular weight, and relative hydroxyproline and proline contents. Thus, conversion of procollagen to collagen is likely to occur in vivo by a proteolytic mechanism. The additional peptide sequences in procollagen may serve to initiate chain association in triple-helix formation, to facilitate molecular transport, and to inhibit intracellular fibrogenesis.
journal_name
Proc Natl Acad Sci U S Aauthors
Bellamy G,Bornstein Pdoi
10.1073/pnas.68.6.1138subject
Has Abstractpub_date
1971-06-01 00:00:00pages
1138-42issue
6eissn
0027-8424issn
1091-6490journal_volume
68pub_type
杂志文章abstract::Factor XI (plasma thromboplastin antecedent) deficiency is a blood coagulation abnormality occurring in high frequency in Ashkenazi Jews. Three independent point mutations that result in a blood coagulation abnormality have been identified in the factor XI gene of six unrelated Ashkenazi patients. These mutations eith...
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.86.20.7667
更新日期:1989-10-01 00:00:00
abstract::In cultures of spleen cells from normal mice, recombinant human granulocyte colony-stimulating factor (G-CSF) supported the formation of multipotential blast cell colonies. Serial replating of the blast cell colonies in the presence of G-CSF, however, failed to demonstrate any direct effect of G-CSF on murine multipot...
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.85.10.3445
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abstract::Excitation of HbCO by a single 6-psec 530-nm pulse results in photodissociation with a first-order constant of 0.89 X 10(11) sec-1. The kinetics of photodissociation, monitored by following absorbance changes in the Soret band at 440 nm, are interpreted as corresponding to predissociation followed by a corssing into 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.75.2.573
更新日期:1978-02-01 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.81.15.4722
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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.92.20.9245
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abstract::The hypothetical scanning (HS) method is a general approach for calculating the absolute entropy and free energy by analyzing Boltzmann samples obtained by Monte Carlo (MC) or molecular dynamics techniques. With HS applied to a fluid, each configuration i of the sample is reconstructed by adding its atoms gradually to...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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abstract::Friend murine leukemia virus (F-MuLV) is a replication-competent retrovirus that induces a rapidly fetal leukemia in susceptible mice (stage I disease). Leukemia cells obtained from these animals do not grow in cell culture using standard tissue culture conditions. However, in the presence of WEHI-3 cell-conditioned m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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doi:10.1073/pnas.81.17.5464
更新日期:1984-09-01 00:00:00
abstract::Social interactions are fundamental for human behavior, but the quantification of their neural underpinnings remains challenging. Here, we used hyperscanning functional MRI (fMRI) to study information flow between brains of human dyads during real-time social interaction in a joint attention paradigm. In a hardware se...
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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.72.11.4582
更新日期:1975-11-01 00:00:00
abstract::Mice lacking major histocompatibility complex (MHC) antigens were generated by mating beta 2-microglobulin-deficient, and therefore class I-deficient, animals with MHC class II-deficient animals. When housed under sterile conditions, the resulting MHC-deficient mice appear healthy, survive for many months, and breed 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.90.9.3913
更新日期:1993-05-01 00:00:00
abstract::Micro-RNAs (miR genes) are a large family of highly conserved noncoding genes thought to be involved in temporal and tissue-specific gene regulation. MiRs are transcribed as short hairpin precursors ( approximately 70 nt) and are processed into active 21- to 22-nt RNAs by Dicer, a ribonuclease that recognizes target m...
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:2002-11-26 00:00:00
abstract::Production of mature erythrocytes requires multiple growth factors, but we do not know how their actions are coordinated. Here we show that erythroid progenitors from erythropoietin receptor (Epo-R)-/- fetal livers, infected in vitro with a retrovirus expressing the wild-type Epo-R, require addition of both Epo and st...
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.94.5.1806
更新日期:1997-03-04 00:00:00
abstract::Atmospheric models generally assume that aerosol particles are in equilibrium with the surrounding gas phase. However, recent observations that secondary organic aerosols can exist in a glassy state have highlighted the need to more fully understand the kinetic limitations that may control water partitioning in ambien...
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:2012-07-17 00:00:00
abstract::The yeast auxiliary transcription factor GAL11, a candidate for the coactivator, was partially purified from yeast cells, and its function was characterized in a cell-free transcription system. The partially purified GAL11 protein stimulated basal transcription from the CYC1 core promoter by a factor of 4-5 at the ste...
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.90.18.8382
更新日期:1993-09-15 00:00:00
abstract::We have measured the opioid receptor reserve in the guinea pig ileum myenteric plexus by means of the site-directed alkylating agent, beta-chlornaltrexamine. Treatment of the tissue with low (less than 10 nM) concentrations of beta-chlornaltrexamine caused a parallel shift of the log concentration-response curves 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.81.22.7253
更新日期:1984-11-01 00:00:00
abstract::Mammalian ferritin from horse spleen undergoes an electrochemical or chemical reduction reaction in which each iron atom present is reduced by one electron (2300 electrons per ferritin molecule containing 2300 Fe3+ ions). Midpoint potentials of -190 mV, -310 mV, and -416 mV were determined at pH 7.0, 8.0, and 9.0. Thi...
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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abstract::p97/VCP (Cdc48 in yeast) is an essential and abundant member of the AAA+ family of ATPases and is involved in a number of diverse cellular pathways through interactions with different adaptor proteins. The two most characterized adaptors for p97 are p47 and the Ufd1 (ubiquitin fusion degradation 1)-Npl4 (nuclear prote...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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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:2015-06-23 00:00:00
abstract::The female germ cell stage of primary importance in radiation genetic hazards is the immature, arrested oocyte. In the mouse, this stage has a near zero or zero sensitivity to mutation induction by radiation. However, the application of these mouse results to women has been questioned on the ground that the mouse arre...
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.74.8.3523
更新日期:1977-08-01 00:00:00
abstract::Although some important advances in the modeling of sorption and hygrothermal deformations of nanoporous materials such as hydrated cement paste, shale, coal, and some other rocks and soils have already been made, a comprehensive nanoporomechanics theory remains elusive. Here we strive to formulate it based on Gibb's ...
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:2020-02-18 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:2011-12-06 00:00:00
abstract::Absolute pitch (AP) is the rare ability to identify the pitch of a tone without the aid of a reference tone. Understanding both the nature and genesis of AP can provide insights into neuroplasticity in the auditory system. We explored factors that may influence the accuracy of pitch perception in AP subjects both duri...
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:2007-09-11 00:00:00
abstract::Fas, a member of the tumor necrosis factor receptor family, can induce apoptosis when activated by Fas ligand binding or anti-Fas antibody crosslinking. Genetic studies have shown that a defect in Fas-mediated apoptosis resulted in abnormal development and function of the immune system in mice. A point mutation in the...
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:1995-12-05 00:00:00
abstract::The substrate specificity of thermophilic xylose isomerase from Clostridium thermosulfurogenes was examined by using predictions from the known crystal structure of the Arthrobacter enzyme and site-directed mutagenesis of the thermophile xylA gene. The orientation of glucose as a substrate in the active site of the 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.88.9.4015
更新日期:1991-05-01 00:00:00
abstract::The rat insulin-like growth factor II gene, encoding a fetal somatomedin, expresses a multitranscript family in embryonic/fetal tissues and in the adult brain and spinal cord. By performing in situ hybridization on tissue sections of adult brain and spinal cord, we have found that these transcripts are not expressed i...
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:1988-01-01 00:00:00
abstract::We measured the dependence of the variance in the rotation rate of tethered cells of Escherichia coli on the mean rotation rate over a regime in which the motor generates constant torque. This dependence was compared with that of broken motors. In either case, motor torque was augmented with externally applied torque....
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.92.8.3502
更新日期:1995-04-11 00:00:00
abstract::In recent years, advertisers and magazine editors have been widely criticized for taking digital photo retouching to an extreme. Impossibly thin, tall, and wrinkle- and blemish-free models are routinely splashed onto billboards, advertisements, and magazine covers. The ubiquity of these unrealistic and highly idealize...
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.1110747108
更新日期:2011-12-13 00:00:00