A general method for determining helix packing in membrane proteins in situ: helices I and II are close to helix VII in the lactose permease of Escherichia coli.

abstract：:How much free energy is irreversibly lost during a thermodynamic process? For deterministic protocols, lower bounds on energy dissipation arise from the thermodynamic friction associated with pushing a system out of equilibrium in finite time. Recent work has also bounded the cost of precisely moving a single degree o...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bryant SJ,Machta BB

更新日期：2020-02-18 00:00:00

abstract：:High-resolution mapping of cofactor-specific photochemistry in photosynthetic reaction centers (RCs) from Rhodobacter sphaeroides was achieved by polarization selective ultrafast spectroscopy in single crystals at cryogenic temperature. By exploiting the fixed orientation of cofactors within crystals, we isolated a si...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Huang L,Ponomarenko N,Wiederrecht GP,Tiede DM

更新日期：2012-03-27 00:00:00

abstract：:We recently reported that CD3- natural killer (NK) cells express the zeta chain of the T-cell receptor complex (zeta NK) in association with higher molecular weight structures whose expression differs between individual NK cell clones. Because NK cell cytolytic activity is known to be triggered by perturbation of the ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Anderson P,Caligiuri M,O'Brien C,Manley T,Ritz J,Schlossman SF

更新日期：1990-03-01 00:00:00

abstract：:Crystals of magnetite (Fe(3)O(4)) and periclase (MgO) in Fe-Mg-Ca carbonate in the Martian meteorite Allan Hills 84001 were studied by using transmission electron microscopy to understand their origin and evaluate claims that the magnetites were made by Martian microorganisms. In magnesian carbonate, periclase occurs ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Barber DJ,Scott ER

更新日期：2002-05-14 00:00:00

abstract：:Five patients with advanced breast cancer were treated with pooled dialyzable transfer factor from healthy adult donors. The period of treatment ranged from 21 to 310 days, the total dose from 20 to 257 ml. Transfer factor did not elicit inflammatory or hypersensitivity reactions or detectable formation of antibody to...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Oettgen HF,Old LJ,Farrow JH,Valentine FT,Lawrence HS,Thomas L

更新日期：1974-06-01 00:00:00

abstract：:Mutations of the VHL tumor suppressor gene occur in patients with VHL disease and in the majority of sporadic clear cell renal carcinomas (VHL(-/-) RCC). Loss of VHL protein function is associated with constitutive expression of mRNAs encoding hypoxia-inducible proteins, such as vascular endothelial growth factor. Ove...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： de Paulsen N,Brychzy A,Fournier MC,Klausner RD,Gnarra JR,Pause A,Lee S

更新日期：2001-02-13 00:00:00

abstract：:The DNA of functional cis-regulatory modules displays extensive sequence conservation in comparisons of genomes from modestly distant species. Patches of sequence that are several hundred base pairs in length within these modules are often seen to be 80-95% identical, although the flanking sequence cannot even be alig...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cameron RA,Chow SH,Berney K,Chiu TY,Yuan QA,Krämer A,Helguero A,Ransick A,Yun M,Davidson EH

更新日期：2005-08-16 00:00:00

abstract：:Endocrine therapy resistance invariably develops in advanced estrogen receptor-positive (ER+) breast cancer, but the underlying mechanisms are largely unknown. We have identified C-terminal SRC kinase (CSK) as a critical node in a previously unappreciated negative feedback loop that limits the efficacy of current ER-t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Xiao T,Li W,Wang X,Xu H,Yang J,Wu Q,Huang Y,Geradts J,Jiang P,Fei T,Chi D,Zang C,Liao Q,Rennhack J,Andrechek E,Li N,Detre S,Dowsett M,Jeselsohn RM,Liu XS,Brown M

更新日期：2018-07-31 00:00:00

abstract：:Recombinant techniques allow one to engineer an antibody molecule and, in this way, manipulate its properties and functions. We engineered a chimeric human/mouse antibody to the tumor-associated antigen ganglioside GD2, with the aim of decreasing its serum half-life, maintaining its full antigen-binding capacity, and ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mueller BM,Reisfeld RA,Gillies SD

更新日期：1990-08-01 00:00:00

abstract：:Activins and inhibins, members of the type beta transforming growth factor superfamily of growth regulatory proteins, are produced in multiple tissues and affect diverse physiologic processes. Using embryonic stem cell technology, we previously demonstrated that inhibin can function as a gonadal tumor suppressor. In t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Matzuk MM,Finegold MJ,Mather JP,Krummen L,Lu H,Bradley A

更新日期：1994-09-13 00:00:00

abstract：:Container-shaped molecules provide structured environments that impart geometric bounds on the motions and conformations of smaller molecular occupants. Moreover, they provide "solvation" that is constrained in time and space. When inwardly directed functional groups are present, they can interact chemically with the ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Purse BW,Rebek J Jr

更新日期：2005-08-02 00:00:00

abstract：:The phosphorylation of H2Ax on its S139 site, γH2Ax, is important during DNA double-strand repair and is considered necessary for assembly of repair complexes, but its functional role after other kinds of DNA damage is less clear. We have measured the survival of isogenic mouse cell lines with the H2Ax gene knocked ou...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Revet I,Feeney L,Bruguera S,Wilson W,Dong TK,Oh DH,Dankort D,Cleaver JE

更新日期：2011-05-24 00:00:00

abstract：:A biological membrane is conceptualized as a system in which membrane proteins are naturally matched to the equilibrium thickness of the lipid bilayer. Cholesterol, in addition to lipid composition, has been suggested to be a major regulator of bilayer thickness in vivo because measurements in vitro have shown that ch...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mitra K,Ubarretxena-Belandia I,Taguchi T,Warren G,Engelman DM

更新日期：2004-03-23 00:00:00

abstract：:The mathematical theory of compressed sensing (CS) asserts that one can acquire signals from measurements whose rate is much lower than the total bandwidth. Whereas the CS theory is now well developed, challenges concerning hardware implementations of CS-based acquisition devices--especially in optics--have only start...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Studer V,Bobin J,Chahid M,Mousavi HS,Candes E,Dahan M

更新日期：2012-06-26 00:00:00

abstract：:We previously have shown that proliferating lymphoid cells contain an extractable cytoplasmic protein that is capable of inducing DNA synthesis in isolated quiescent nuclei (activator of DNA replication, ADR). ADR is present in continuously proliferating (transformed) lymphoblastoid cell lines and in mitogen- or inter...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gutowski JK,West A,Cohen S

更新日期：1985-08-01 00:00:00

abstract：:Although heparin and low-molecular-weight heparins (LMWH) have been widely used clinically as anticoagulants, their broader use has been limited by the lack of noninvasive delivery methods for this class of molecules. In this study, we demonstrate an efficient, rapid, and reproducible delivery system for heparin throu...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Qi Y,Zhao G,Liu D,Shriver Z,Sundaram M,Sengupta S,Venkataraman G,Langer R,Sasisekharan R

更新日期：2004-06-29 00:00:00

abstract：:The ever-increasing industrial demand for nylon-6 (polycaprolactam) necessitates the development of environmentally benign methods of producing its precursor, epsilon-caprolactam, from cyclohexanone. It is currently manufactured in two popular double-step processes, each of which uses highly aggressive reagents, and e...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Thomas JM,Raja R

更新日期：2005-09-27 00:00:00

abstract：:Genotype-phenotype relationships are notoriously complicated. Idiosyncratic interactions between specific combinations of mutations occur and are difficult to predict. Yet it is increasingly clear that many interactions can be understood in terms of global epistasis. That is, mutations may act additively on some under...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Otwinowski J,McCandlish DM,Plotkin JB

更新日期：2018-08-07 00:00:00

abstract：:Filtration through the kidney eliminates toxins, manages electrolyte balance, and controls water homeostasis. Reabsorption of water from the luminal fluid of the nephron occurs through aquaporin-2 (AQP2) water pores in principal cells that line the kidney-collecting duct. This vital process is impeded by formation of ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Whiting JL,Ogier L,Forbush KA,Bucko P,Gopalan J,Seternes OM,Langeberg LK,Scott JD

更新日期：2016-07-26 00:00:00

abstract：:Natural killer (NK) cells are key players in the innate response to viruses, including herpesviruses. In particular, the variety of viral strategies to modulate the recognition of certain herpesviruses witnesses the importance of NK cells in the control of this group of viruses. Still, NK evasion strategies have remai...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Grauwet K,Cantoni C,Parodi M,De Maria A,Devriendt B,Pende D,Moretta L,Vitale M,Favoreel HW

更新日期：2014-11-11 00:00:00

abstract：:Perhydrohistrionicotoxin, at concentrations of 10(-12)-10(-7) M, depressed the current generated by iontophoretic application of acetylcholine to endplate regions of soleus and extensor digitorum longus muscles of rats. However, no changes in the amplitude or time course of spontaneous miniature endplate potentials or...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Albuquerque EX,Gage PW

更新日期：1978-03-01 00:00:00

abstract：:Arsenate is an abundant oxyanion that, because of its ability to mimic the phosphate group, is toxic to cells. Arsenate reductase (EC; encoded by the arsC gene in bacteria) participates to achieve arsenate resistance in both prokaryotes and yeast by reducing arsenate to arsenite; the arsenite is then exported by a spe...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bennett MS,Guan Z,Laurberg M,Su XD

更新日期：2001-11-20 00:00:00

abstract：:Three allelic variants of P-pilus-associated G-adhesins (lectins) with different cell-binding properties were recently described. Here we have analyzed Escherichia coli HB101 strains expressing the recombinant G-adhesin variants for their ability to agglutinate erythrocytes from various species as this relates to the ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Strömberg N,Nyholm PG,Pascher I,Normark S

更新日期：1991-10-15 00:00:00

abstract：:Residues important in the interaction between the 23-residue transmembrane (TM) domains of the integrin alpha(IIb)- and beta(3)-subunits were identified by mutating each non-Leu residue to Leu. Leu substitutions of alpha(IIb) at G972, G976, and T981, and of beta(3) at I693 and G708, increased ligand binding. Substitut...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Luo BH,Carman CV,Takagi J,Springer TA

更新日期：2005-03-08 00:00:00

abstract：:A fundamental property of ecosystems is a tradeoff between the number and size of habitats: as the number of habitats within a fixed area increases, the average area per habitat must decrease. This tradeoff is termed the "area-heterogeneity tradeoff." Theoretical models suggest that the reduction in habitat sizes unde...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ben-Hur E,Kadmon R

更新日期：2020-03-03 00:00:00

abstract：:The stator ring of the bacterial flagellar motor is composed of the MotA and MotB proteins that act together to generate a turning force (torque) acting on the FliG ring of the rotor. The C-terminal domain of MotB (MotB-C) is believed to anchor the MotA/MotB complex to peptidoglycan (PG) of the cell wall. The first cr...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Roujeinikova A

更新日期：2008-07-29 00:00:00

abstract：:The last 2 decades have seen discoveries in highly excited states of atoms and molecules of phenomena that are qualitatively different from the "planetary" model of the atom, and the near-rigid model of molecules, characteristic of these systems in their low-energy states. A unified view is emerging in terms of approx...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kellman ME

更新日期：1996-12-10 00:00:00

abstract：:Water autoionization reaction 2H2O --> H3O- + OH- is a textbook process of basic importance, resulting in pH = 7 for pure water. However, pH of pure water surface is shown to be significantly lower, the reduction being caused by proton stabilization at the surface. The evidence presented here includes ab initio and cl...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Buch V,Milet A,Vácha R,Jungwirth P,Devlin JP

更新日期：2007-05-01 00:00:00

abstract：:In photosynthetic systems, the absorbed light energy is used to generate electron transport or it is lost in the form of fluorescence and thermal emission. While fluorescence can be readily measured, the detection of thermal deactivation processes can be achieved by the photoacoustic technique. In that case, the press...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Allakhverdiev SI,Klimov VV,Carpentier R

更新日期：1994-01-04 00:00:00

abstract：:Autocatalytic chemical reactions are widely studied as models of biological processes and to better understand the origins of life on Earth. Minimal self-reproducing amphiphiles have been developed in this context and as an approach to de novo "bottom-up" synthetic protocells. How chemicals come together to produce li...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ortega-Arroyo J,Bissette AJ,Kukura P,Fletcher SP

更新日期：2016-10-04 00:00:00