Search results for "binding"

Precision Mass Measurements beyondSn132: Anomalous Behavior of Odd-Even Staggering of Binding Energies

2012

Atomic masses of the neutron-rich isotopes $^{121--128}\mathrm{Cd}$, $^{129,131}\mathrm{In}$, $^{130--135}\mathrm{Sn}$, $^{131--136}\mathrm{Sb}$, and $^{132--140}\mathrm{Te}$ have been measured with high precision (10 ppb) using the Penning-trap mass spectrometer JYFLTRAP. Among these, the masses of four $r$-process nuclei $^{135}\mathrm{Sn}$, $^{136}\mathrm{Sb}$, and $^{139,140}\mathrm{Te}$ were measured for the first time. An empirical neutron pairing gap expressed as the odd-even staggering of isotopic masses shows a strong quenching across $N=82$ for Sn, with a $Z$ dependence that is unexplainable by the current theoretical models.

Observing myoglobin proteinquake with an X-ray free-electron laser

2015

The events following the photodissociation of the bond be- tween myoglobin and its ligand have been extensively studied with a variety of experimental, theoretical and computational methods [1]. The results of these investigations have been rationalized in terms of a model that implies a protein quake- like motion [2], i.e. the propagation of the strain released upon photoexcitation through the protein similar to the prop- agation of acoustic waves during an earthquake. The exper- imental investigations performed so far have been based on spectroscopic measurements or did not have sufficient time- resolution to measure the timescale of such “proteinquake”. We have obtained direct experiment…

Interactions entre la beta-lactoglobuline et les arômes : impact au niveau moléculaire

2008

Interactions between β-lactoglobulin (BLG) and aroma compounds were investigated by complementary techniques for a better knowledge of binding mechanisms between proteins and aroma compounds at a molecular scale. Two binding sites have been defined for the monomeric BLG, one internal site within the central calyx, and one external site between the calyx and the α helix. In a first step, a relation between the ligand structure and its binding behaviour was established from the study of impact of a wide range of aroma compounds on the structure of native BLG. We evidenced at least two binding behaviours as a function of the chemical class, the hydrophobicity, or the structure of the ligands. …

The Enterotoxin from Clostridium difficile (ToxA) Monoglucosylates the Rho Proteins

1995

The enterotoxin from Clostridium difficile (ToxA) is one of the causative agents of the antibiotic-associated pseudomembranous colitis. In cultured monolayer cells ToxA exhibits cytotoxic activity to induce disassembly of the actin cytoskeleton, which is accompanied by morphological changes. ToxA-induced depolymerization of actin filaments is correlated with a decrease in the ADP-ribosylation of the low molecular mass GTP-binding Rho proteins (Just, I., Selzer, J., von Eichel-Streiber, C., and Aktories, K. (1995) J. Clin. Invest. 95, 1026-1031). Here we report on the identification of the ToxA-induced modification of Rho. Applying electrospray mass spectrometry, the mass of the modification…

Rho prevents apoptosis through Bcl-2 expression: Implications for interleukin-2 receptor signal transduction

1997

Here we describe a Rho-mediated apoptosis suppression pathway driven by Bcl-2 expression in the interleukin (IL)-4- or IL-2-dependent murine T cell line TS1 alpha beta. IL-2, but not IL-4, induces Bcl-2 expression through RhoA activation which is inhibited by the specific Rho family inhibitor, Clostridium difficile Toxin B, as well as by a dominant negative RhoA mutant. Using transient transfections of RhoA mutants tagged with the vesicular stomatitis virus glycoprotein, we show that a constitutively active RhoA mutant induces Bcl-2 expression and prevents apoptosis upon IL-4 withdrawal. Finally, we have identified the signaling pathway involved together with RhoA in Bcl-2 induction and sho…

Clostridium difficile toxin A induces expression of the stress-induced early gene product RhoB.

2004

Clostridium difficile toxin A monoglucosylates the Rho family GTPases Rho, Rac, and Cdc42. Glucosylation leads to the functional inactivation of Rho GTPases and causes disruption of the actin cytoskeleton. A cDNA microarray revealed the immediate early gene rhoB as the gene that was predominantly up-regulated in colonic CaCo-2 cells after treatment with toxin A. This toxin A effect was also detectable in epithelial cells such as HT29 and Madin-Darby canine kidney cells, as well as NIH 3T3 fibroblasts. The expression of RhoB was time-dependent and correlated with the morphological changes of cells. The up-regulation of RhoB was approximately 15-fold and was based on the de novo synthesis of …

The ras-related small GTP-binding protein RhoB is immediate-early inducible by DNA damaging treatments.

1995

The low molecular weight GTP-binding proteins RhoA, RhoB, and RhoC are characterized as specific substrates for the ADP-ribosyltransferase C3 from Clostridium botulinum and are supposed to be involved in the organization of the microfilamental network and transformation. rhoB is known to be immediate-early inducible by growth factors and protein-tyrosine kinases. Since increasing evidence indicates overlapping of growth factor- and UV-induced signal pathways, we studied the effect of UV light and other genotoxic agents on early rhoB transcription. Within 30 min after UV irradiation of NIH3T3 cells, the amount of rhoB mRNA increased 3-4-fold. Elevated rhoB mRNA was accompanied by an increase…

Analysis of interaction between messenger RNA encoding H3.3 histone variant and pippin protein by biolayer interferometry

2013

RNA-Binding Proteins which interact with mRNAs for H1° and H3.3 histone variants

2014

Determinants of intracellular RNA pharmacokinetics: Implications for RNA-based immunotherapeutics

2011

RNAs with optimized properties are increasingly investigated as a tool to deliver the genetic information of complete antigens into professional antigen-presenting dendritic cells for HLA haplotype-independent antigen-specific vaccination against cancer. As the dose of the antigen and duration of its presentation are critical factors for generating strong and sustained antigen-specific immune responses, improvement of the immunobioavailability of RNA-based vaccines has been a recurrent subject of research. Substantial increase of the amount of antigen produced from RNA can be achieved by optimizing RNA stability and translational efficiency. Both features are determined by cis-acting elemen…