Abstract:
:The structural analysis of the Fab' fragment of human myeloma immunoglobulin IgGl(lambda) New has been extended to a nominal resolution of 2.0 A. Each of the structural subunits corresponding to the variable and to the constant homology regions of the light and heavy chains contains two irregular beta-sheets which are roughly parallel to each other and surround a tightly packed interior of hydrophobic side chains. About 50-60% of the amino-acid residues are included in beta-pleated sheets. Sequence alignments between the homology regions of Fab' New obtained by comparison of their three-dimensional structures are given. Some of the sequence variations observed in light and heavy chains and the role of the regions of hypervariable sequence in defining the size and shape of the active site of different immunoglobulin molecules are discussed on the basis of the three-dimensional model of Fab' New.
journal_name
Proc Natl Acad Sci U S Aauthors
Poljak RJ,Amzel LM,Chen BL,Phizackerley RP,Saul Fdoi
10.1073/pnas.71.9.3440subject
Has Abstractpub_date
1974-09-01 00:00:00pages
3440-4issue
9eissn
0027-8424issn
1091-6490journal_volume
71pub_type
杂志文章abstract::Syncytins are envelope genes of retroviral origin that have been co-opted for a role in placentation and likely contribute to the remarkable diversity of placental structures. Independent capture events have been identified in primates, rodents, lagomorphs, and carnivores, where they are involved in the formation of 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.1215787110
更新日期:2013-02-26 00:00:00
abstract::The density of benzodiazepine/gamma-aminobutyric acid receptor binding sites was lower in the midbrain of seizure-susceptible gerbils compared to control seizure-resistant gerbils. Binding of [3H]diazepam to high-affinity brain-specific sites in membrane homogenates of gerbil brain showed a 20-30% lower binding in mid...
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.82.19.6701
更新日期:1985-10-01 00:00:00
abstract::To evaluate [3H]phencyclidine ([3H]PCP)as a probe for the ionic channel of the nicotinic receptor, the characteristics of its binding to electric organ membranes od Torpedo ocellata and its effects on frog sartorius muscle were studied. Similar to PCP, [3H]PCP depressed the peak amplitude of endplate current, caused 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.77.12.7458
更新日期:1980-12-01 00:00:00
abstract::Under anesthesia with sodium pentobarbital, the sciatic nerves of rats were transected bilaterally, and a catheter was inserted into the central end of the left renal artery. After an initial flush, an Alzet pump was attached to the catheter, containing various concentrations of glycyl-L-glutamine (Gly-Gln), methylpre...
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.87.23.9495
更新日期:1990-12-01 00:00:00
abstract::Certain Escherichia coli mutants defective in phosphatidylglycerol biosynthesis accumulate two novel glycolipids, designated X and Y. Lipid X is a diacylglucosamine 1-phosphate bearing beta-hydroxymyristoyl groups at positions 2 and 3, and lipid Y has the same structure as X, except for the additional presence of a pa...
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.82.2.282
更新日期:1985-01-01 00:00:00
abstract::Juvenile hormone III (JH) plays a key role in regulating the reproduction of female mosquitoes. Microarray time-course analysis revealed dynamic changes in gene expression during posteclosion (PE) development in the fat body of female Aedes aegypti. Hierarchical clustering identified three major gene clusters: 1,843 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.1305293110
更新日期:2013-06-11 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::Vibrio cholerae serogroup O139 emerged on the Indian subcontinent in October 1992 to become the first non-O1 V. cholerae serogroup documented to cause epidemic cholera. Although related to V. cholerae El Tor O1 strains, O139 strains have unique surface structures that include a capsular surface layer and lipopolysacch...
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.91.24.11388
更新日期:1994-11-22 00:00:00
abstract::A cDNA clone that hybridizes to an mRNA (1A10) that accumulates to a substantial level in the axis of the germinating soybean seed was sequenced. The amino acid sequence of the clone indicates an almost perfect repeat of Pro-Pro-Val-Tyr-Lys resulting in a protein containing 40% proline and lacking serine and histidine...
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.85.4.1082
更新日期:1988-02-01 00:00:00
abstract::All immunoglobulins and T-cell receptors throughout phylogeny share regions of highly conserved amino acid sequence. To identify possible primitive immunoglobulins and immunoglobulin-like molecules, we utilized 3' RACE (rapid amplification of cDNA ends) and a highly conserved constant region consensus amino acid 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.93.8.3289
更新日期:1996-04-16 00:00:00
abstract::Duodenal bicarbonate secretion (DBS) is accepted as the primary mucosal defense against acid discharged from the stomach and is impaired in patients with duodenal ulcer disease. The secretory response to luminal acid is the main physiological stimulus for DBS and involves mediation by PGE2 produced by mucosal cells. 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.0508007102
更新日期:2005-10-18 00:00:00
abstract::We discuss the pulling force f required to extrude a lipid tube from a living cell as a function of the extrusion velocity L. The main feature is membrane friction on the cytoskeleton. As recently observed for neutrophils, the tether force exhibits a "shear thinning" response over a large range of pulling velocities, ...
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.0602012103
更新日期:2006-05-16 00:00:00
abstract::An enhancer specific to erythroid cells was identified previously in the 3' flanking sequence of the chicken adult beta-globin gene and shown to act on the beta-globin promoter. This enhancer lies between the adult beta-globin gene and the embryonic epsilon-globin gene, about equidistant from the two promoters. To det...
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.85.8.2548
更新日期:1988-04-01 00:00:00
abstract::Ler, a homolog of H-NS in enteropathogenic Escherichia coli (EPEC), plays a critical role in the expression of virulence genes encoded by the pathogenic island, locus of enterocyte effacement (LEE). Although Ler acts as an antisilencer of multiple LEE operons by alleviating H-NS-mediated silencing, it represses its ow...
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.1322033111
更新日期:2014-06-24 00:00:00
abstract::We have identified an adenovirus type 5(Ad5) early gene function located in early region 1 which is required for the production of early cytoplasmic mRNAs corresponding to early regions 2, 3, and 4. Mutant dl312 (lacks the segment between 1.5 and 4.5 map units) grows as well as wild-type virus in 293 cells (Ad5-trans...
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.76.8.3665
更新日期:1979-08-01 00:00:00
abstract::Seawater Mg:Ca and Sr:Ca ratios are biogeochemical parameters reflecting the Earth-ocean-atmosphere dynamic exchange of elements. The ratios' dependence on the environment and organisms' biology facilitates their application in marine sciences. Here, we present a measured single-laboratory dataset, combined with previ...
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.1918943117
更新日期:2020-09-08 00:00:00
abstract::There is great interest in developing selective protein kinase inhibitors by targeting allosteric sites, but these sites often involve protein-protein or protein-peptide interfaces that are very challenging to target with small molecules. Here we present a systematic approach to targeting a functionally conserved allo...
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.1415365112
更新日期:2014-12-30 00:00:00
abstract::The structure of the Rous sarcoma virus envelope glycoprotein complex was studied by sedimentation gradient centrifugation analyses of detergent-solubilized wild-type and mutant envelope (env) gene products. These studies show that the envelope glycoprotein forms an oligomer during biosynthesis, which is most likely 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.85.22.8688
更新日期:1988-11-01 00:00:00
abstract::Direct conversion of carbon dioxide to multicarbon products remains as a grand challenge in electrochemical CO2 reduction. Various forms of oxidized copper have been demonstrated as electrocatalysts that still require large overpotentials. Here, we show that an ensemble of Cu nanoparticles (NPs) enables selective form...
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.1711493114
更新日期:2017-10-03 00:00:00
abstract::The effect of RNA secondary structure on rho-independent and rho-dependent termination of transcription of T3 DNA by Escherichia coli RNA polymerase has been studied by incorporating, into nascent transcripts, base analogs that lead to altered base-pairing properties. A guanine --> hypoxanthine substitution, with atte...
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.76.4.1613
更新日期:1979-04-01 00:00:00
abstract::A topological model of the DNA binding site for the cyclic AMP receptor protein (CRP) is presented. A consensus sequence drawn from the known CRP binding sites has several symmetrical subregions that are spatially resolved onto different faces of the DNA helix. Consideration of available biochemical and genetic data 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.78.4.2213
更新日期:1981-04-01 00:00:00
abstract::Antimicrobial levels of reactive oxygen species (ROS) are produced by the mammalian host defense to kill invading bacteria and limit bacterial colonization. One main in vivo target of ROS is the thiol group of proteins. We have developed a quantitative thiol trapping technique termed OxICAT to identify physiologically...
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.0707723105
更新日期:2008-06-17 00:00:00
abstract::Intercropping, which grows at least two crop species on the same pieces of land at the same time, can increase grain yields greatly. Legume-grass intercrops are known to overyield because of legume nitrogen fixation. However, many agricultural soils are deficient in phosphorus. Here we show that a new mechanism of ove...
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.0704591104
更新日期:2007-07-03 00:00:00
abstract::The FKBP12-rapamycin-associated protein (FRAP; also called RAFT1/mTOR) regulates translation initiation and entry into the cell cycle. Depriving cells of amino acids or treating them with the small molecule rapamycin inhibits FRAP and results in rapid dephosphorylation and inactivation of the translational regulators ...
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.96.8.4438
更新日期:1999-04-13 00:00:00
abstract::Mycobacterium marinum, a natural pathogen of fish and frogs and an occasional pathogen of humans, is capable of inducing actin tail formation within the cytoplasm of macrophages, leading to actin-based motility and intercellular spread. Actin tail formation by M. marinum is markedly reduced in macrophages deficient in...
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.0504663102
更新日期:2005-10-11 00:00:00
abstract::Splice variants (SVs) of receptors for growth hormone-releasing hormone (GHRH) have been found in primary human prostate cancers and diverse human cancer cell lines. GHRH antagonists inhibit growth of various experimental human cancers, including pancreatic and colorectal, xenografted into nude mice or cultured in vit...
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.182433099
更新日期:2002-09-03 00:00:00
abstract::We previously purified a 48-kDa protein (p48) that specifically reacts with an antiserum directed against the 12 carboxyl-terminal amino acids of the c-myc gene product. Using an antiserum directed against the purified p48, we have cloned a cDNA from a human expression library. This cDNA hybrid-selects an mRNA that 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.83.18.6741
更新日期:1986-09-01 00:00:00
abstract::Whereas several apoptosis-related proteins have been linked to the antiapoptotic effects of Akt serine-threonine kinase, the search continues to explain the Akt signaling role in promoting cell survival via antiapoptotic effects. Here, we demonstrate that Akt phosphorylates the androgen receptor (AR) at Ser-210 and Se...
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.121173298
更新日期:2001-06-19 00:00:00
abstract::Ribonuclease H (EC 3.1.4.34) has been used to remove selectively much of the 3'-terminal poly(adenylic acid) [poly(A)] from poliovirus RNA by treating the RNA with the enzyme in the presence of poly(dT). Over 80% of the poly(A) could be removed and the residuum was found as oligo(A) stretches attached to many or all 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.71.8.2983
更新日期:1974-08-01 00:00:00
abstract::Cyclic AMP concentrations were low for an adenylate cyclase-deficient mutant (cya(-)) and abnormally high for a catabolite receptor protein-deficient mutant (crp(-)). A fall in cellular cAMP concentration was always found when cells were subjected to transient repression. No consistent correlations were observed betwe...
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.71.4.1436
更新日期:1974-04-01 00:00:00