Abstract:
:Spontaneous cross-linking in vitro, during incubation of purified collagen in nonstriated and native type fibrils, was studied to elucidate the relationship between intra and intermolecular cross-links. In nonbanded fibrils, the aldol condensation products of two allysyl residues, previously shown to constitute the intramolecular cross-link, formed spontaneously and could be isolated as such, whereas in native type fibrils, these compounds were found to be incorporated into an intermolecular cross-link; after chemical reduction they could not be isolated. Similar results were obtained from studies on a native collagenous tissue, rat tail tendon. It is suggested that the intramolecular cross-link is not a separate entity but only an intermediate of an intermolecular cross-link and that its existence in solubilized collagen is a result of the extraction procedure. The quantitative formation of intramolecular cross-links in vitro and identification of the cross-link compound are also reported.
journal_name
Proc Natl Acad Sci U S Aauthors
Kang AH,Gross Jdoi
10.1073/pnas.67.3.1307subject
Has Abstractpub_date
1970-11-01 00:00:00pages
1307-14issue
3eissn
0027-8424issn
1091-6490journal_volume
67pub_type
杂志文章abstract::Host species have evolved mechanisms that can inhibit pathogen replication even after a cell has been successfully invaded. Here we show that tripartite-motif protein 21 (TRIM21), a ubiquitously expressed E3 ubiquitin ligase that targets viruses inside the cytosol, protects mice against fatal viral infection. Upon inf...
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.1301918110
更新日期:2013-07-23 00:00:00
abstract::We examined the distributions of short tandemly repeated DNAs (microsatellites) in nine complete microbial genomes (Saccharomyces cerevisiae, Archaeoglobus fulgidus, Escherichia coli, Haemophilus influenzae, Helicobacter pylori, Methanococcus jannaschii, Mycoplasma pneumoniae, M. genitalium, and Synechocystis PCC6803....
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.95.4.1647
更新日期:1998-02-17 00:00:00
abstract::Successful implementation of bone marrow transplantation for hematopoietic reconstitution is limited by the lack of suitably HLA-matched donors and by the occurrence of graft-versus-host disease that frequently accompanies this procedure. Recent clinical reports have implied that the use of umbilical cord blood as a 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.89.21.10006
更新日期:1992-11-01 00:00:00
abstract::Class I major histocompatibility complex (MHC) antigens are confronted with an apparently insurmountable dilemma. Each should show a binding preference to a common enough variety of nonapeptides, so that one relevant nonapeptide can be found in at least every other viral protein to provoke a cytotoxic T-cell response....
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.89.10.4643
更新日期:1992-05-15 00:00:00
abstract::Intracellular proteolytic processing of precursor polypeptides is an essential step in the maturation of many proteins, including plasma proteins, hormones, neuropeptides, and growth factors. Most frequently, propeptide cleavage occurs after paired basic amino acid residues. To date, no mammalian propeptide processing...
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.87.23.9378
更新日期:1990-12-01 00:00:00
abstract::Egg activation is the process in which mature oocytes are released from developmental arrest and gain competency for embryonic development. In Drosophila and other arthropods, eggs are activated by mechanical pressure in the female reproductive tract, whereas in most other species, eggs are activated by fertilization....
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.1906967116
更新日期:2019-09-17 00:00:00
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::Tephritid fruit flies belonging to the Rhagoletis pomonella sibling species complex are controversial because they have been proposed to diverge in sympatry (in the absence of geographic isolation) by shifting and adapting to new host plants. Here, we report evidence suggesting a surprising source of genetic variation...
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.1730757100
更新日期:2003-09-02 00:00:00
abstract::Studies of biotic remains of polar ice caps have been limited to morphological identification of plant pollen and spores. By using sensitive molecular techniques, we now demonstrate a much greater range of detectable organisms; from 2000- and 4000-year-old ice-core samples, we obtained and characterized 120 clones tha...
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.96.14.8017
更新日期:1999-07-06 00:00:00
abstract::The crystal structure of Escherichia coli ornithine transcarbamoylase (OTCase, EC 2.1.3.3) complexed with the bisubstrate analog N-(phosphonacetyl)-L-ornithine (PALO) has been determined at 2.8-A resolution. This research on the structure of a transcarbamoylase catalytic trimer with a substrate analog bound provides n...
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.94.18.9550
更新日期:1997-09-02 00:00:00
abstract::The sea anemone, Nematostella vectensis, has become an attractive new model organism for comparative genomics and evolutionary developmental biology. Over the last few years, many genes have been isolated and their expression patterns studied to gain insight into their function. More recently, functional tools have be...
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.0909148107
更新日期:2010-01-05 00:00:00
abstract::Among 21 human mammary tumors analyzed for transforming genes by transfection of NIH/3T3 cells, only DNA of a carcinosarcoma cell line, HS578T, registered as positive. A Harvey (H)-ras oncogene identified in this line was cloned in biologically active form and the activating lesion was identified as a single nucleotid...
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.81.17.5384
更新日期:1984-09-01 00:00:00
abstract::The enzyme p-cresol methylhydroxylase [4-cresol: (acceptor) oxidoreductase (methyl-hydroxylating), EC 1.17.99.1] contains two subunits: a cytochrome c (electron transfer) subunit (cytochrome cpc) and a flavin (catalytic) subunit. When these subunits are separated by isoelectric focusing, a stable cytochrome subunit is...
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.88.21.9463
更新日期:1991-11-01 00:00:00
abstract::The in vivo biological activities of IgG antibodies result from their bifunctional nature, in which antigen recognition by the Fab is coupled to the effector and immunomodulatory diversity found in the Fc domain. This diversity, resulting from both amino acid and glycan heterogeneity, is translated into cellular respo...
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.1203954109
更新日期:2012-04-17 00:00:00
abstract::The origin of highly magnetized white dwarfs has remained a mystery since their initial discovery. Recent observations indicate that the formation of high-field magnetic white dwarfs is intimately related to strong binary interactions during post-main-sequence phases of stellar evolution. If a low-mass companion, such...
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.1015005108
更新日期:2011-02-22 00:00:00
abstract::Long-range conformational changes in proteins are ubiquitous in biology for the transmission and amplification of signals; such conformational changes can be triggered by small-amplitude, nanosecond protein domain motion. Understanding how conformational changes are initiated requires the characterization of protein d...
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.0503388102
更新日期:2005-12-06 00:00:00
abstract::Male relationships in most species of mammals generally are characterized by intense intrasexual competition, with little bonding among unrelated individuals. In contrast, human societies are characterized by high levels of cooperation and strong bonds among both related and unrelated males. The emergence of cooperati...
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.1405811111
更新日期:2014-10-14 00:00:00
abstract::The N-methyl-D-aspartate (NMDA) receptor, a subtype of excitatory amino acid receptor, mediates synaptic responses in many regions of the central nervous system. This receptor plays a critical role in the mechanisms of both synaptic plasticity and excitotoxicity. Although these receptors were generally thought to be 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.85.24.9836
更新日期:1988-12-01 00:00:00
abstract::Recent experiments have shown that mouse primary visual cortex (V1) is very different from that of cat or monkey, including response properties-one of which is that contrast invariance in the orientation selectivity (OS) of the neurons' firing rates is replaced in mouse with contrast-dependent sharpening (broadening) ...
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.1719044115
更新日期:2018-11-06 00:00:00
abstract::The activation of cyclin-dependent kinases (cdks) has been implicated in apoptosis induced by various stimuli. We find that the Fas-induced activation of cdc2 and cdk2 in Jurkat cells is not dependent on protein synthesis, which is shut down very early during apoptosis before caspase-3 activation. Instead, activation ...
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.95.12.6785
更新日期:1998-06-09 00:00:00
abstract::One of the advantages of the production of monoclonal antibodies by tissue culture methods is that they can be internally labeled by using appropriate radioactive amino acid in the culture fluid. Thus, radioactive immunological probes of high specific activity can be prepared. Here we report applications of these inte...
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.79.2.665
更新日期:1982-01-01 00:00:00
abstract::For almost a century the plant hormone auxin has been central to theories on apical dominance, whereby the growing shoot tip suppresses the growth of the axillary buds below. According to the classic model, the auxin indole-3-acetic acid is produced in the shoot tip and transported down the stem, where it inhibits bud...
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.1322045111
更新日期:2014-04-22 00:00:00
abstract::Although antibodies to HLA play a role in the pathogenesis of diseases processes such as rejection of transplanted organs, the precise mechanisms by which antibodies cause tissue injury are not completely understood. We hypothesized that antibodies to host tissues cause inflammation in part by activating endothelial 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.0602035104
更新日期:2007-01-23 00:00:00
abstract::The emergence of multidrug-resistant (MDR) tuberculosis (TB) highlights the urgent need to understand the mechanisms of resistance to the drugs used to treat this disease. The aminoglycosides kanamycin and amikacin are important bactericidal drugs used to treat MDR TB, and resistance to one or both of these drugs is 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.0907925106
更新日期:2009-11-24 00:00:00
abstract::It is well established that the medial-temporal lobe (MTL) is critical for recognition memory. The MTL is known to be composed of distinct structures that are organized in a hierarchical manner. At present, it remains controversial whether lower structures in this hierarchy, such as perirhinal cortex, support memory f...
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.0705273104
更新日期:2007-10-09 00:00:00
abstract::Online education is rapidly expanding in response to rising demand for higher and continuing education, but many online students struggle to achieve their educational goals. Several behavioral science interventions have shown promise in raising student persistence and completion rates in a handful of courses, but evid...
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.1921417117
更新日期:2020-06-30 00:00:00
abstract::Murine and human cDNAs, related to but distinct from c-raf-1, have been isolated and designated mA-raf and hA-raf, respectively. The mA-raf and hA-raf cDNAs detect the same murine and human fragments in Southern blots of restriction enzyme-cleaved murine and human cellular DNA. The murine restriction enzyme fragments ...
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.83.11.3934
更新日期:1986-06-01 00:00:00
abstract::T-cell-derived soluble factors that inhibit both X4 and R5 HIV are recognized as important in controlling HIV. Whereas three β chemokines, regulated-on-activation normal T-cell expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-1α, and MIP-1β, account for the suppression of R5 HIV by blockade of HI...
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.1202240109
更新日期:2012-04-03 00:00:00
abstract::B-1a cells reside in both the peritoneal cavity and the spleen. LPS stimulates splenic B-1a to differentiate to plasma cells producing natural IgM specific for microbial and self antigens. However, there are conflicting views as to whether the B-1a cells divide before this differentiation occurs, and hence how the res...
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.0700001104
更新日期:2007-03-13 00:00:00
abstract::Granulocyte-colony-stimulating factor (G-CSF) stimulates the proliferation and differentiation of cells of the neutrophil lineage by interaction with a specific receptor. Early signal transduction events following G-CSF receptor activation were studied. We detected tyrosine phosphorylation of both the G-CSF receptor 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.91.8.2985
更新日期:1994-04-12 00:00:00