Abstract:
:Maltose-binding protein (MBP) is a two-domain protein that undergoes a ligand-mediated conformational rearrangement from an "open" to a "closed" structure on binding to maltooligosaccharides. To characterize the energy landscape associated with this transition, we have generated five variants of MBP with mutations located in the hinge region of the molecule. Residual dipolar couplings, measured in the presence of a weak alignment medium, have been used to establish that the average structures of the mutant proteins are related to each other by domain rotation about an invariant axis, with the rotation angle varying from 5 degrees to 28 degrees. Additionally, the domain orientations observed in the wild-type apo and ligand-bound (maltose, maltotriose, etc.) structures are related through a rotation of 35 degrees about the same axis. Remarkably, the free energy of unfolding, measured by equilibrium denaturation experiments and monitored by fluorescence spectroscopy, shows a linear correlation with the rotation angle, with the stability of the (apo)protein decreasing with domain closure by 212 +/- 16 cal mol-1 per degree of rotation. The apparent binding energy for maltose also shows a similar correlation with the interdomain angle, suggesting that the mutations, as they relate to binding, affect predominantly the ligand-free structure. The linearity of the energy change is interpreted in terms of an increase in the extent of hydrophobic surface that becomes solvent accessible on closure. The combination of structural, stability, and binding data allows separation of the energetics of domain reorientation from ligand binding. This work presents a near quantitative structure-energy-binding relationship for a series of mutants of MBP, illustrating the power of combined studies involving protein engineering and solution NMR spectroscopy.
journal_name
Proc Natl Acad Sci U S Aauthors
Millet O,Hudson RP,Kay LEdoi
10.1073/pnas.2134311100keywords:
subject
Has Abstractpub_date
2003-10-28 00:00:00pages
12700-5issue
22eissn
0027-8424issn
1091-6490pii
2134311100journal_volume
100pub_type
杂志文章abstract::Vertically transmitted symbionts that protect their hosts against parasites and pathogens are well known from insects, yet the underlying mechanisms of symbiont-mediated defense are largely unclear. A striking example of an ecologically important defensive symbiosis involves the woodland fly Drosophila neotestacea, wh...
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.1518648113
更新日期:2016-01-12 00:00:00
abstract::Adoptive cellular immunotherapy, infusions of interleukin 2 (IL-2) in conjunction with in vitro-activated killer cells, has brought new hope to patients with cancer. The broad application of this strategy, however, is constrained by the need for repeated leukapheresis and by the labor-intensive process of in vitro act...
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.91.17.7889
更新日期:1994-08-16 00:00:00
abstract::Photoperiodic control of testis growth in Passer domesticus (house sparrow) is mediated entirely by extraretinal photoreceptors in the brain. The eyes do not participate in photoperiodically significant photoreception. Removal of the pineal organ does not affect either the response to light or, to a first approximatio...
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.67.1.320
更新日期:1970-09-01 00:00:00
abstract::Fetal pancreatic beta cells demonstrate a deficient insulin release in response to glucose, but the underlying mechanism at the cellular level is unknown. By using beta cells from 21-day fetal rats we made an attempt to clarify the mechanism(s) behind this reduced glucose response. In addition to measuring insulin rel...
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.86.12.4505
更新日期:1989-06-01 00:00:00
abstract::Determining trend and implementing detrending operations are important steps in data analysis. Yet there is no precise definition of "trend" nor any logical algorithm for extracting it. As a result, various ad hoc extrinsic methods have been used to determine trend and to facilitate a detrending operation. In this art...
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.0701020104
更新日期:2007-09-18 00:00:00
abstract::We determined the frequency of integrated viral DNA in the livers of three woodchucks chronically infected with the woodchuck hepatitis virus before and during 30 weeks of therapy with the nucleoside analog L-FMAU [1-(2-fluoro-5-methyl-beta, L-arabinofuranosyl)uracil, clevudine]. We found that although viral covalentl...
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.0307422100
更新日期:2004-01-13 00:00:00
abstract::The modern concept of neurogenesis in the adult brain is predicated on the premise that multipotent glial cells give rise to new neurons throughout life. Although extensive evidence exists indicating that this is the case, the transition from glial to neuronal phenotype remains poorly understood. A unique monolayer ce...
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.0503965102
更新日期:2005-06-28 00:00:00
abstract::Intracellular transport is based on molecular motors that pull cargos along cytoskeletal filaments. One motor species always moves in one direction, e.g., conventional kinesin moves to the microtubule plus end, whereas cytoplasmic dynein moves to the microtubule minus end. However, many cellular cargoes are observed 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.0706825105
更新日期:2008-03-25 00:00:00
abstract::We report here the cloning, expression, and characterization of a dual-substrate, cAMP and cGMP, cyclic nucleotide phosphodiesterase (PDE) from mouse. This PDE contains the consensus sequence for a PDE catalytic domain, but shares <50% sequence identity with the catalytic domains of all other known PDEs and, therefore...
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.96.12.7071
更新日期:1999-06-08 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::The relationship between performance and ability is a central concern in the social sciences: Are the most successful much more able than others, and are failures unskilled? Prior research has shown that noise and self-reinforcing dynamics make performance unpredictable and lead to a weak association between ability 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.1116048109
更新日期:2012-06-12 00:00:00
abstract::Phylogenetic differences in acetylcholine receptors from skeletal neuromuscular synapses of various species of snakes and lizards have been investigated, using the snake venom alpha-neurotoxins alpha-atratoxin (cobrotoxin) and alpha-bungarotoxin. The acetylcholine receptors of the phylogenetically primitive lizards, l...
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.72.8.3245
更新日期:1975-08-01 00:00:00
abstract::Tissue cultures of Actinidia kolomikta can be maintained as callus through repeated passages on a nutrient medium devoid of cytokinin but containing inorganic nutrients, sucrose, and other basal organics plus auxin. Under these conditions, actively growing callus contained 2 and 0.5 nmol of the cytokinins zeatin [io(6...
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.83.4.972
更新日期:1986-02-01 00:00:00
abstract::Habitat loss and disease are main drivers of global amphibian declines, yet the interaction between them remains largely unexplored. Here we show that paradoxically, habitat loss is negatively associated with occurrence, prevalence, and infection intensity of the chytrid fungus Batrachochytrium dendrobatidis (Bd) in 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.1014497108
更新日期:2011-06-14 00:00:00
abstract::If climate change outpaces the rate of adaptive evolution within a site, populations previously well adapted to local conditions may decline or disappear, and banked seeds from those populations will be unsuitable for restoring them. However, if such adaptational lag has occurred, immigrants from historically warmer c...
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.1406314111
更新日期:2014-06-03 00:00:00
abstract::Oxidative stress is a ubiquitous threat to all aerobic organisms and has been implicated in numerous pathological conditions such as cancer. Here we demonstrate a pivotal role for E2F1, a cell cycle regulatory transcription factor, in cell tolerance of oxidative stress. Cells lacking E2F1 are hypersensitive to oxidati...
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.1921554117
更新日期:2020-06-30 00:00:00
abstract::We present evidence that the JAK-STAT signal transduction pathway regulates multiple developmental processes in Drosophila. We screened for second-site mutations that suppress the phenotype of the hyperactive hopTum-1 Jak kinase, and recovered a mutation that meiotically maps to the known chromosomal position of D-Sta...
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.93.12.5842
更新日期:1996-06-11 00:00:00
abstract::The substance P (SP)-preferring receptor neurokinin-1 receptor (NK-1R) has two forms: a full-length receptor consisting of 407 aa and a truncated receptor consisting of 311 aa. These two receptors differ in the length of the C terminus of NK-1R. We studied the undifferentiated and phorbol myristate acetate (PMA)-diffe...
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.0602563103
更新日期:2006-05-16 00:00:00
abstract::Herpesvirus saimiri (HVS) is the prototype member of a distinctive subset of lymphotropic herpesviruses (the gamma 2 subgroup) with A+T-rich coding sequences. In this paper, we show that cells productively infected with HVS contain high concentrations of a virus-specified thymidylate synthase (5,10-methylenetetrahydro...
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.83.11.3604
更新日期:1986-06-01 00:00:00
abstract::In view of the extensive literature on phytochrome mutants in the Ler accession of Arabidopsis, we sought to secure a phytochrome-null line in the same genetic background for comparative studies. Here we report the isolation and phenotypic characterization of phyABCDE quintuple and phyABDE quadruple mutants in the Ler...
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.1221738110
更新日期:2013-01-22 00:00:00
abstract::In vitro data show that the adenomatous polyposis coli (APC) protein associates with the mitotic spindle and that mouse embryonic stem cells with biallelic Apc mutations are karyotypically unstable. These findings led to suggestions that APC acts in chromosomal segregation and that APC inactivation leads to chromosoma...
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.012679099
更新日期:2002-12-24 00:00:00
abstract::During clathrin-mediated endocytosis, adaptor proteins recognize specific internalization signals on cargo receptors, either recruiting cargos into clathrin-coated pits (CCPs) or initiating clathrin-coat assembly around the cargo molecules. Here, we identify epsin 1, a clathrin-, ubiquitin-, and phospholipid-interacti...
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.0803711105
更新日期:2008-08-19 00:00:00
abstract::Inflammation and vascular injury triggered by ischemia/reperfusion (I/R) represent a leading cause of morbidity and mortality in a number of clinical settings. Wnt and its homolog partners R-spondins, in addition to regulating embryonic development have recently been demonstrated to serve as wound-healing agents in 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.1309393110
更新日期:2013-08-27 00:00:00
abstract::Most, but not all, aged rats exhibit a profound deficit in spatial memory when tested in a radial maze--a task known to depend on the integrity of the hippocampal formation. In this study, animals were divided into three groups based on their spatial memory capacity: young adult rats with good memory, aged rats with i...
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.83.9.3027
更新日期:1986-05-01 00:00:00
abstract::To gain further insight into the mode of action of S-locus receptor kinase (SRK), a receptor-like kinase involved in the self-incompatibility response in Brassica, different recombinant SRK proteins have been expressed in a membranous environment using the insect cell/baculovirus system. Recombinant SRK proteins exhib...
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.070025097
更新日期:2000-03-28 00:00:00
abstract::Fish have somehow colonized isolated water bodies all over the world without human assistance. It has long been speculated that these colonization events are assisted by waterbirds, transporting fish eggs attached to their feet and feathers, yet empirical support for this is lacking. Recently, it was suggested that en...
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.2004805117
更新日期:2020-07-07 00:00:00
abstract::Transfer of organelle DNA into the nuclear genome has been significant in eukaryotic evolution, because it appears to be the origin of many nuclear genes. Most studies on organelle DNA transfer have been restricted to evolutionary events but experimental systems recently became available to monitor the process in real...
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.0400853101
更新日期:2004-06-29 00:00:00
abstract::Selenophosphate, an activated form of selenium that can serve as a selenium donor, is generated by the selD gene product, selenophosphate synthetase (SPS). Selenophosphate is required by several bacteria and by mammals for the specific synthesis of Secys-tRNA, the precursor of selenocysteine in selenoenzymes. Although...
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.0409042102
更新日期:2005-01-25 00:00:00
abstract::In this study, we compared the transport of newly synthesized cholesterol with that of influenza virus hemagglutinin (HA) from the endoplasmic reticulum to the plasma membrane. The arrival of cholesterol on the cell surface was monitored by cyclodextrin removal, and HA transport was monitored by surface trypsinization...
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.140218797
更新日期:2000-07-18 00:00:00
abstract::We define an integer invariant [Formula: see text] of a smooth, compact, closed 4-manifold X by minimizing a certain complexity of a trisection of X over all trisections. The good feature of [Formula: see text] is that when [Formula: see text] and X is a homology 4-sphere, then X is diffeomorphic to the 4-sphere. Natu...
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.1718953115
更新日期:2018-10-23 00:00:00