Abstract:
:The kinetic inhibition of the gelation of hemoglobin S is compared to the change in hemoglobin S soulbility, when the solubility is altered by carbon monoxide, pH, or urea. By means of a new technique, the delay time and the extent of gelation are measured on the same sample. They delay time, td, is found to be proportional to a high power (30-40) of the hemoglobin S solubility. Togehter with the previously reported concentration dependence, this result demonstrates that the rate is proportional to a high power of the supersaturation, S, defined as the ratio of the total hemoglobin S concentration to the equilibrium solubility. The results obey the supersaturation equation td-1 = gammaSn, where gamma is an empirical constant (about 10(-7) sec-1) and n is about 35. The supersaturation equation can successfully account for observations on the kinetics of cell sickling and is therefore used to estimate the increase in the delay time for sickling necessary to produce significant clinical benefit to patients with sickle cell disease.
journal_name
Proc Natl Acad Sci U S Aauthors
Hofrichter J,Ross PD,Eaton WAdoi
10.1073/pnas.73.9.3035subject
Has Abstractpub_date
1976-09-01 00:00:00pages
3035-9issue
9eissn
0027-8424issn
1091-6490journal_volume
73pub_type
杂志文章abstract::N-methyl-d-aspartate receptors (NMDARs) mediate critical CNS functions, whereas excessive activity contributes to neuronal damage. At physiological glycine concentrations, NMDAR currents recorded from cultured rodent hippocampal neurons exhibited strong desensitization in the continued presence of NMDA, thus protectin...
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.1110789109
更新日期:2012-01-31 00:00:00
abstract::A 90-kDa surface glycoprotein was previously isolated and shown to be required for infection by the "major" group of human rhinovirus (HRV) serotypes. In the present work, the amino acid sequence of the receptor protein was obtained from CNBr and tryptic peptides. Using degenerate oligonucleotides predicted from the p...
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.86.13.4907
更新日期:1989-07-01 00:00:00
abstract::The difficulty of achieving robust functional expression of insect nicotinic acetylcholine receptors (nAChRs) has hampered our understanding of these important molecular targets of globally deployed neonicotinoid insecticides at a time when concerns have grown regarding the toxicity of this chemotype to insect pollina...
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.2003667117
更新日期:2020-07-14 00:00:00
abstract::We have noted consistent structural similarities among unrelated proteases. In comparison with other proteins of similar size, proteases have smaller than average surface areas, smaller radii of gyration, and higher C(alpha) densities. These findings imply that proteases are, as a group, more tightly packed than other...
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.070548997
更新日期:2000-04-11 00:00:00
abstract::The intestinal lamina propria (LP) is a major effector site of the mucosal immune system where antigen-specific and antigen-nonspecific factors shape the functional responses of CD4+ T helper cells. To study the functional differentiation of LP T helper cells we utilized DO11.10 T cell receptor (TCR) transgenic (Tg) m...
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.94.8.3920
更新日期:1997-04-15 00:00:00
abstract::We have determined the complete primary structure of human hemopexin, a plasma beta-glycoprotein that specifically binds one heme with high affinity and transports it to hepatocytes for salvage of the iron. Human hemopexin (Mr approximately equal to 63,000) consists of a single polypeptide chain containing 439 amino 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.82.1.73
更新日期:1985-01-01 00:00:00
abstract::The presence of substance P-immunoreactive (SPI) varicose nerve networks and nerve fiber bundles in guinea pig prevertebral sympathetic ganglia has been confirmed by fluorescence immunohistochemistry. No SPI neurons have been found in sympathetic ganglia, including lumbar paravertebral ganglia. Peroxidase-antiperoxida...
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.79.5.1668
更新日期:1982-03-01 00:00:00
abstract::Eusociality is a major evolutionary innovation involving alterations in life history, morphology, and behavior. Advanced eusocial insects, such as ants, termites, and corbiculate bees, cannot provide insights into the earliest stages of eusocial evolution because eusociality in these taxa evolved long ago (in the Cret...
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.012387999
更新日期:2002-01-08 00:00:00
abstract::Cell type in Saccharomyces yeasts is regulated by two transposable blocks of DNA, the a and alpha cassettes. There are three loci where either cassette can exist. At the HML and HMR loci the cassettes are not expressed. The cassette at the MAT locus is expressed and controls the cell type. Changes of cell type involve...
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.77.5.2839
更新日期:1980-05-01 00:00:00
abstract::Expression cloning of cDNAs was first described a decade ago and was based on transient expression of cDNA libraries in COS cells. In contrast to transient transfection of plasmids, retroviral gene transfer delivers genes stably into a wide range of target cells. We utilize a simple packaging system for production 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.92.20.9146
更新日期:1995-09-26 00:00:00
abstract::Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease in the tropics and subtropics with high morbidity and mortality. The facultative intracellular bacterium induces host cell fusion through its type VI secretion system 5 (T6SS5) as an important part of its pathogenesis in mammalian h...
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.2006908117
更新日期:2020-07-07 00:00:00
abstract::Cell fusion was induced by brain extracts containing the scrapie virus and the virus of Creutzfeldt-Jakob disease. The assay involved quantitation of colony-forming ability in a double selection system, strandardized against fusion induced by Sendai virus. Correlation between the logarithm of virus dilution and the hy...
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.75.6.2969
更新日期:1978-06-01 00:00:00
abstract::cis-jasmone, or (Z)-jasmone, is well known as a component of plant volatiles, and its release can be induced by damage, for example during insect herbivory. Using the olfactory system of the lettuce aphid to investigate volatiles from plants avoided by this insect, (Z)-jasmone was found to be electrophysiologically ac...
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.160241697
更新日期:2000-08-01 00:00:00
abstract::We demonstrate theoretically and experimentally the spontaneous clustering of solitons in partially coherent wavefronts during the final stages of pattern formation initiated by modulation instability and noise. ...
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.072287299
更新日期:2002-04-16 00:00:00
abstract::The glycogen content of yeast rises dramatically just before the onset of the stationary phase of growth. Concomitantly, a rapid increase was found in the glucose 6-phosphate-independent (I) activity of glycogen synthetase, as well as in the total amount of enzyme. A mutant (GS 1-36) was obtained, which did not accumu...
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.66.3.967
更新日期:1970-07-01 00:00:00
abstract::Among the 15 extracellular domains of the mannose 6-phosphate/insulin-like growth factor-2 receptor (M6P/IGF2R), domain 11 has evolved a binding site for IGF2 to negatively regulate ligand bioavailability and mammalian growth. Despite the highly evolved structural loops of the IGF2:domain 11 binding site, affinity-enh...
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.1513023113
更新日期:2016-05-17 00:00:00
abstract::Miraculin (MCL) is a homodimeric protein isolated from the red berries of Richadella dulcifica. MCL, although flat in taste at neutral pH, has taste-modifying activity to convert sour stimuli to sweetness. Once MCL is held on the tongue, strong sweetness is sensed over 1 h each time we taste a sour solution. Neverthel...
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.1016644108
更新日期:2011-10-04 00:00:00
abstract::Mutations of MECP2 (Methyl-CpG Binding Protein 2) cause Rett syndrome. As a chromatin-associated multifunctional protein, how MeCP2 integrates external signals and regulates neuronal function remain unclear. Although neuronal activity-induced phosphorylation of MeCP2 at serine 421 (S421) has been reported, the full sp...
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.0811648106
更新日期:2009-03-24 00:00:00
abstract::In this paper, we describe the structure of chitinase B from Serratia marcescens, which consists of a catalytic domain with a TIM-barrel fold and a 49-residue C-terminal chitin-binding domain. This chitinase is the first structure of a bacterial exochitinase, and it represents one of only a few examples of a glycosyl ...
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.97.11.5842
更新日期:2000-05-23 00:00:00
abstract::We report a general mass spectrometric approach for the rapid identification and characterization of proteins isolated by preparative two-dimensional polyacrylamide gel electrophoresis. This method possesses the inherent power to detect and structurally characterize covalent modifications. Absolute sensitivities of ma...
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.92.11.5072
更新日期:1995-05-23 00:00:00
abstract::The human immunodeficiency virus type 1 (HIV-1) trans-activator protein, Tat, specifically stimulates transcription from the viral long terminal repeat. Tat binds to an RNA stem-loop structure encoded by the trans-activation response region (TAR). To test whether TAR is functional when displaced downstream of the star...
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.92.6.2408
更新日期:1995-03-14 00:00:00
abstract::The formation of nerve-muscle junctions in monolayer cultures of embryonic muscle and spinal cord cells is described. Muscle-forming cells (myoblasts) from leg muscles of 12-day chick embryos were separated with trypsin and cultured on a collagen substrate for two days. Suspensions of ventral spinal cord cells from si...
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.62.3.715
更新日期:1969-03-01 00:00:00
abstract::We have examined the functional consequences of mutations present in defective alleles of the retinoblastoma susceptibility gene (RB1) isolated from two spontaneously arising tumors. Unlike cDNA clones expressing the wild-type protein p110Rb, those encoding the two mutant proteins failed to induce the appearance of 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.88.8.3033
更新日期:1991-04-15 00:00:00
abstract::Since at least the 1920s, it has been reported that common chimpanzees (Pan troglodytes) differ from humans in being capable of exceptional feats of "super strength," both in the wild and in captive environments. A mix of anecdotal and more controlled studies provides some support for this view; however, a critical re...
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.1619071114
更新日期:2017-07-11 00:00:00
abstract::We are presented with choices each day about how to invest our effort to achieve our goals. Critically, these decisions must frequently be made under conditions of incomplete information, where either the effort required or possible reward to be gained is uncertain. Such choices therefore require the development of po...
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.1800444115
更新日期:2018-05-29 00:00:00
abstract::We used positron emission tomography (PET) to examine the role of the hippocampal formation in implicit and explicit memory. Human volunteers studied a list of familiar words, and then they either provided the first word that came to mind in response to three-letter cues (implicit memory) or tried to recall studied wo...
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.93.1.321
更新日期:1996-01-09 00:00:00
abstract::The electrical currents at the surface of the proximal portion of an isolated and transected lamprey spinal cord were measured with an extracellular vibrating probe. Soon after transection, currents of about 0.5 mA/cm2 enter the cut surface of the spinal cord. These currents fall to about a quarter of their initial va...
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.77.2.1209
更新日期:1980-02-01 00:00:00
abstract::Four polyimidazoles were used in the binding and cleavage studies with poly(U). The two polydisperse polyvinylimidazoles were previously described by others, while the other two new polymers of polyethyleneimines were prepared by cationic polymerization of oxazolines. The latter had imidazole units attached to each ni...
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.1210846109
更新日期:2012-08-07 00:00:00
abstract::Nations in the 21st century face a complex mix of environmental and social challenges, as highlighted by the on-going Sustainable Development Goals process. The "planetary boundaries" concept [Rockström J, et al. (2009) Nature 461(7263):472-475], and its extension through the addition of social well-being indicators 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.1400985111
更新日期:2014-10-21 00:00:00
abstract::The current study identifies CCR8+ regulatory T cells (Treg cells) as drivers of immunosuppression. We show that in human peripheral blood cells, more than 30% of Treg up-regulate CCR8 following activation in the presence of CCL1. This interaction induces STAT3-dependent up-regulation of FOXp3, CD39, IL-10, and granzy...
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.1621280114
更新日期:2017-06-06 00:00:00