Abstract:
:Variants of A/PR/8/34 (HON1) influenza virus, having hemagglutinin molecules with probably a single altered antigenic determinant, were isolated by growing the virus in the presence of the monoclonal hybridoma antibody PEG-1. The variants were analyzed by peptide mapping and characterized antigenically by using PEG-1 and four other monoclonal hybridoma antibodies to PR8 hemagglutinin. Peptide maps of the large hemagglutinin polypeptide, HA1, from 8 out of 10 variants showed a single changed peptide. This peptide from two of the variants was analyzed, and in each case a serine residue in the wild-type hemagglutinin was replaced by leucine in the variant. Although these eight variants showed identical peptide maps, one could be discriminated antigenically from the others with one of the hybridomas. (The peptide maps represented about one-third of the HA1 molecule.) Of the other two variants, one gave the same HA1 map as the wild type, but could be distinguished antigenically from wild-type virus by two of the hybridomas. The other was unique, and could be distinguished, both antigenically and by peptide mapping, from the other variants. Since a large number of the variants selected with PEG-1 showed the same peptide change, it is likely that this alteration in amino acid sequence (serine to leucine) was responsible for the inability of the variants to bind PEG-1 monoclonal antibody. We do not know, however, whether the changed amino acids were located within the antigenic sites or whether the change occurred somewhere else in the hemagglutinin molecule and altered the determinants through conformational changes.
journal_name
Proc Natl Acad Sci U S Aauthors
Laver WG,Gerhard W,Webster RG,Frankel ME,Air GMdoi
10.1073/pnas.76.3.1425subject
Has Abstractpub_date
1979-03-01 00:00:00pages
1425-9issue
3eissn
0027-8424issn
1091-6490journal_volume
76pub_type
杂志文章abstract::In adult rat testes, the blood-testis barrier (BTB) in the seminiferous epithelium must "open" (or "disassemble") to accommodate the migration of preleptotene spermatocytes from the basal to the adluminal compartment that occurs at stage VIII of the epithelial cycle. However, the molecule(s) and/or mechanism(s) that r...
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.0610100104
更新日期:2007-03-06 00:00:00
abstract::The unique specificity of monoclonal antibodies (Ab) was combined with the cell-killing function of the cytolytic alternative pathway of complement. The functionally C3b-like glycoprotein of cobra venom was linked to a murine monoclonal Ab directed to a human melanoma-associated antigen by a disulfide bond, by using 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.78.12.7707
更新日期:1981-12-01 00:00:00
abstract::In aqueous solution, aldehydes, and to a lesser extent ketones, hydrate to form geminal diols. We investigate the hydration of methylglyoxal (MG) in the gas phase, a process not previously considered to occur in water-restricted environments. In this study, we spectroscopically identified methylglyoxal diol (MGD) and ...
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.0912121107
更新日期:2010-04-13 00:00:00
abstract::DNA "breathing" is a thermally driven process in which base-paired DNA sequences transiently adopt local conformations that depart from their most stable structures. Polymerases and other proteins of genome expression require access to single-stranded DNA coding templates located in the double-stranded DNA "interior,"...
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.1314862110
更新日期:2013-10-22 00:00:00
abstract::The inability to perceive and coordinate both internal and external signals that function to regulate cellular growth and proliferation is a hallmark of oncogenic transformation. To examine the effects of the v-mos oncogene on distinct signal transduction pathways, the 6m2 cell line was used, in which expression of 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.86.2.597
更新日期:1989-01-01 00:00:00
abstract::Parinaric acid (9,11,13,15-octadecatetraenoic acid), a conjugated tetraene fatty acid, undergoes a second-order photochemical reaction in phospholipid bilayers. The reaction results in the loss of the characteristic absorption of this chromophore and the development of new absorption demonstrating the presence of a tr...
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.77.1.26
更新日期:1980-01-01 00:00:00
abstract::The DNA-binding protein CCCTC-binding factor (CTCF) and the cohesin complex function together to shape chromatin architecture in mammalian cells, but the molecular details of this process remain unclear. Here, we demonstrate that a 79-aa region within the CTCF N terminus is essential for cohesin positioning at CTCF bi...
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.1911708117
更新日期:2020-01-28 00:00:00
abstract::Vaccinia virus encodes a multisubunit DNA-dependent RNA polymerase (EC 2.7.7.6) that is packaged in the infectious virus particle. This polymerase was found to contain a submolar polypeptide of approximately 85 kDa in addition to the core subunits, which consist of two larger and several smaller polypeptides. The poly...
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.89.8.3536
更新日期:1992-04-15 00:00:00
abstract::Although it is known that the c-myc oncogene is rearranged in a head-to-head fashion with the immunoglobulin heavy chain locus in mouse plasmacytomas, it has not been clear whether the c-myc oncogene is translocated to the heavy chain locus on mouse chromosome 12 or whether the heavy chain locus is translocated to 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.82.12.4212
更新日期:1985-06-01 00:00:00
abstract::Granulocytes generate a "respiratory burst" of NADPH oxidase-dependent superoxide anion (O(2)(-*)) production that is required for efficient clearance of bacterial pathogens. Hv1 mediates a voltage-gated H(+) channel activity that is proposed to serve a charge-balancing role in granulocytic phagocytes such as neutroph...
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.0902761106
更新日期:2009-05-05 00:00:00
abstract::Replication of the kinetoplast DNA (kDNA) minicircle of trypanosomatids initiates at a conserved 12-nt sequence, 5'-GGGGTTGGTGTA-3', termed the universal minicircle sequence (UMS). A sequence-specific single-stranded DNA-binding protein from Crithidia fasciculata binds the heavy strand of the 12-mer UMS. Whereas this ...
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.92.23.10511
更新日期:1995-11-07 00:00:00
abstract::The cdc25 phosphatases play key roles in cell cycle progression by activating cyclin-dependent kinases. Two members of the 14-3-3 protein family have been isolated in a yeast two-hybrid screen designed to identify proteins that interact with the human cdc25A and cdc25B phosphatases. Genes encoding the human homolog 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.92.17.7892
更新日期:1995-08-15 00:00:00
abstract::Ras proteins are small GTP binding proteins that serve as critical relays in a variety of signal transduction pathways in eukaryotic cells. Like most metazoan Ras proteins, yeast Ras is post-translationally modified by addition of a farnesyl and a palmitoyl moiety, and these modifications are required for targeting 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.92.7.2984
更新日期:1995-03-28 00:00:00
abstract::Lysine to methionine (K-to-M) mutations in genes encoding histone H3 are thought to drive a subset of pediatric brain and bone cancers. These high-frequency K-to-M mutations occur at sites of methylation on histone H3, and tumors containing the mutant histones exhibit a global loss of specific histone methylation mark...
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.1605523113
更新日期:2016-05-31 00:00:00
abstract::Human craniofacial data were used to assess the similarities and differences between recent and prehistoric Old World samples, and between these samples and a similar representation of samples from the New World. The data were analyzed by the neighbor-joining clustering procedure, assisted by bootstrapping and by cano...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.171305898
更新日期:2001-08-14 00:00:00
abstract::The 5' region of the mouse gamma-glutamyltransferase (gamma GT; EC 2.3.2.2) gene has been cloned and analyzed. This analysis, combined with sequence information obtained from gamma GT cDNA clones, indicates that in mouse a single gamma GT gene codes for six different mRNAs that differ in their 5' sequences. Analysis 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.90.13.6179
更新日期:1993-07-01 00:00:00
abstract::Normal monkeys and monkeys with lesions of the hippocampal formation and adjacent cortex (the H+ lesion) were trained on the delayed nonmatching to sample (DNMS) task with a delay of 0.5 s between the sample and the choice. The animals with H+ lesions learned the task normally at this short delay and also exhibited 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.91.12.5637
更新日期:1994-06-07 00:00:00
abstract::Influenza hemagglutinin (HA) is the primary target of the humoral response during infection/vaccination. Current influenza vaccines typically fail to elicit/boost broadly neutralizing antibodies (bnAbs), thereby limiting their efficacy. Although several bnAbs bind to the conserved stem domain of HA, focusing the immun...
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.1402766111
更新日期:2014-06-24 00:00:00
abstract::A survey was performed to estimate the frequency of enterohemorrhagic Escherichia coli O157:H7 or O157:nonmotile (EHEC O157) in feces and on hides within groups of fed cattle from single sources (lots) presented for slaughter at meat processing plants in the Midwestern United States, as well as frequency of carcass co...
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.060024897
更新日期:2000-03-28 00:00:00
abstract::Hematopoietic stem/progenitor cells (HSPCs) possess the potentials of self-renewal, proliferation, and differentiation toward different lineages of blood cells. These cells not only play a primordial role in hematopoietic development but also have important clinical application. Characterization of the gene expression...
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.95.14.8175
更新日期:1998-07-07 00:00:00
abstract::Pathway proteomics strategies measure protein expression changes in specific cellular processes that carry out related functions. Using targeted tandem mass tags-based sample multiplexing, hundreds of proteins can be quantified across 10 or more samples simultaneously. To facilitate these highly complex experiments, w...
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.1919410117
更新日期:2020-05-05 00:00:00
abstract::The present investigation studied the influence of the blastocyst's state of activity on the "window" of implantation in the receptive uterus in the mouse. The receptive state of the uterus is defined as the limited time when the uterine milieu is favorable to blastocyst acceptance and implantation. In the mouse, impl...
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.90.21.10159
更新日期:1993-11-01 00:00:00
abstract::In the nitrogen-fixing symbiosis between legume hosts and rhizobia, the bacteria are engulfed by a plant cell membrane to become intracellular organelles. In the model legume Medicago truncatula, internalization and differentiation of Sinorhizobium (also known as Ensifer) meliloti is a prerequisite for nitrogen fixati...
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.1500123112
更新日期:2015-12-08 00:00:00
abstract::To visualize histone acetylation in living cells, we developed a genetically encoded fluorescent resonance energy transfer (FRET)-based indicator. Response of the indicator reflects changes in the acetylation state of both K5 and K8 in histone H4. Using this acetylation indicator, we were able to monitor the dynamic 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.0902150106
更新日期:2009-09-22 00:00:00
abstract::The plant hormone abscisic acid (ABA) is produced in response to abiotic stresses and mediates stomatal closure in response to drought via recently identified ABA receptors (pyrabactin resistance/regulatory component of ABA receptor; PYR/RCAR). SLAC1 encodes a central guard cell S-type anion channel that mediates ABA-...
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.1116590109
更新日期:2012-06-26 00:00:00
abstract::To initiate transcription from specific promoters, the bacterial RNA polymerase (RNAP) core enzyme must associate with the initiation factor sigma, which contains determinants that allow sequence-specific interactions with promoter DNA. Most bacteria contain several sigma factors, each of which directs recognition 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.0812832106
更新日期:2009-04-21 00:00:00
abstract::The rRNA intervening sequence of Tetrahymena is a catalytic RNA molecule, or "ribozyme." A tertiary-structure model of the active site of this ribozyme has been constructed based on comparative sequence analysis of related group I intervening sequences, data on the accessibility of each nucleotide to chemical and enzy...
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.84.24.8788
更新日期:1987-12-01 00:00:00
abstract::The exocytosis of AMPA receptors is a key step in long-term potentiation (LTP), yet the timing and location of exocytosis and the signaling pathways involved in exocytosis during synaptic plasticity are not fully understood. Here we combine two-photon uncaging with two-photon imaging of a fluorescent label of surface ...
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.0913875107
更新日期:2010-09-07 00:00:00
abstract::Excited states of proteins may play important roles in function, yet are difficult to study spectroscopically because of their sparse population. High hydrostatic pressure increases the equilibrium population of excited states, enabling their characterization [Akasaka K (2003) Biochemistry 42:10875-85]. High-pressure ...
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.1320124110
更新日期:2013-12-03 00:00:00
abstract::An algorithm for protein engineering, termed recursive ensemble mutagenesis, has been developed to produce diverse populations of phenotypically related mutants whose members differ in amino acid sequence. This method uses a feedback mechanism to control successive rounds of combinatorial cassette mutagenesis. Startin...
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.89.16.7811
更新日期:1992-08-15 00:00:00