Search results for "binding"
showing 10 items of 3896 documents
On the role of D-glucuronic acid in the aggregation of cells from the marine sponge Geodia cydonium.
1979
Abstract The aggregation receptor (AR) from the marine sponge GEODIA CYDONIUM was analyzed with respect to its monosaccharide composition. Three major sugars ( D -galactose, D -glucose and D -glucuronic acid) accounted for about 85 % of the total carbohydrate. Negative results with different lectins directed against D -galactosyl, N -acetyl- D -galactosaminyl and N -acetyl- D -glucosaminyl groups, respectively, showed that these sugars are serologically unreactive in AR. Positive serological reactions were obtained with CONCANAVALIN A and LIMULUS POLYPHEMUS agglutinin. AR also reacted strongly with the basic polymer poly- L -lysine. Reaggregation experiments performed on the basis of these …
The structural effect between the output module and chromophore-binding domain is a two-way street via the hairpin extension.
2022
AbstractSignal transduction typically starts with either ligand binding or cofactor activation, eventually affecting biological activities in the cell. In red light-sensing phytochromes, isomerization of the bilin chromophore results in regulation of the activity of diverse output modules. During this process, several structural elements and chemical events influence signal propagation. In our study, we have studied the full-length bacteriophytochrome from Deinococcus radiodurans as well as a previously generated optogenetic tool where the native histidine kinase output module has been replaced with an adenylate cyclase. We show that the composition of the output module influences the stabi…
Nested allosteric interactions in extracellular hemoglobin of the leech Macrobdella decora
2003
Hemoglobin from the leech Macrobdella decora belongs to the class of giant extracellular hexagonal bilayer globin structures found in annelid and vestimentiferan worms. These complexes consist of 144 heme-bearing subunits, exhibit a characteristic quaternary structure (2 × (6 × (3 × 4))), and contain tetramers as basic substructures that express cooperative oxygen binding and thus provide a structural basis for a hierarchy in allosteric interactions. A thorough analysis of the isolated tetramer indicates that it functions as a trimer of cooperatively interacting subunits and a non-cooperative monomer rather than as four interacting subunits. A thermodynamic analysis of the whole molecule fa…
Crystal Structure and Host-Guest Binding Ability of Three Types of Pillar[5]arenes
2015
A systematic research of the structural characterization and the host-guest binding abilities between three types of pillar[5]arenes 3–5 (3 for Structure Type I, 4 for Structure Type II and 5 for Structure Type III) is carried out by 1H NMR measurements and X-ray study. The results show that the configurations or symmetry of their cavities not only have large difference in these three types of pillar[5]arenes, but also have more or less variations even in the same structure type or the same host locked different guests such as crystals of 3a–3b, 4a–4d. On the other hand, the complexation behavior of pillar[5]arenes with 1,4-dibromobutane (DBB) is affected by the different symmetrical struct…
Utilization of water glass as an activator in the manufacturing of cementitious materials from waste by-products
1987
Abstract In the present paper, the possibility of producing new-type cementless building materials is discussed when water glass as an activating agent is used. The experimental data are presented for a set of raw materials which normally do not show any binding ability. However, if they undergo some physico-chemical treatment and water glass is used, a solid structure of the material is formed. According to the method described here, lots of different mineral waste by-products could be activated, thus gaining binding properties.
Calorimetric and viscosimetric investigation of the interaction between α,β-polyasparthydrazide and sodium dodecyl sulfate micelles
1993
Abstract The interaction between α,β-polyasparthydrazide (PAHy) and sodium dodecyl sulfate (SDS) micelles in aqueous solution was investigated by calorimetry and viscosimetry. The dependence of the enthalpic effect due to this interaction upon the surfactant concentration was rationalized in terms of a progressive binding of SDS micelles to the polymeric backbone. The analysis of the calorimetric data allow evaluation of the binding ability of SDS micelles to the polymeric chain. The viscosimetric behavior of SDS plus PAHy aqueous solutions, discussed in terms of the parameter F [F = ηrel(PAHy) + ηrel(PAHy) − ηrel(SDS+PAHy)], confirms the occurence of the interaction between SDS micelles an…
Identification and functional binding analysis of GPR23/! LPA4 as a candidate G protein-coupled receptor for Guanosine.
2013
Several studies have shown that guanine-based purines exert biological effects on the central nervous system (CNS), possibly through membrane receptors, but at the present there are not reports related to the identification of such specific receptor(s). We have identified the first guanosine G protein-coupled receptor GPR23, also known as LPA4 receptor, involved in the modulation of guanosine-mediated antiproliferative effects in human glioma cell line (U87). We report that the silencing of GPR23 reduces significantly the antiproliferative effects of guanosine, while stably transfected cell clones over-expressing GPR23 increase sensitivity to guanosine. [3H] Guanosine radioligand binding as…
The effect of N-tetradecyl-N,N-dimethylamine oxide micelles on the kinetics of the electron transfer reaction of Ce(IV) with substituted malonic acids
2009
Abstract The kinetics of the oxidation of malonic acid and (its substituted compounds, methyl-, ethyl-, butyl- and benzyl-malonic acid) by ceric ions has been studied at 20.0 °C in the absence and the presence of the surfactant N-tetradecyl-N,N-dimethylamine oxide (C 14 DMAO). The addition of increasing amounts of C 14 DMAO influences the rate of the redox process to an extent that significantly depends on the hydrophobicity of the reducing species. The reactivity data together with the estimated binding constants and the standard transfer free energies of the malonic acids from water to the micelles suggest that the malonic acid is confined to the aqueous pseudo-phase while for the other s…
Mass measurements beyond the major r-process waiting point $^{80}$Zn
2008
High-precision mass measurements on neutron-rich zinc isotopes 71m,72-81Zn have been performed with the Penning trap mass spectrometer ISOLTRAP. For the first time the mass of 81Zn has been experimentally determined. This makes 80Zn the first of the few major waiting points along the path of the astrophysical rapid neutron capture process where neutron separation energy and neutron capture Q-value are determined experimentally. As a consequence, the astrophysical conditions required for this waiting point and its associated abundance signatures to occur in r-process models can now be mapped precisely. The measurements also confirm the robustness of the N = 50 shell closure for Z = 30 farthe…
Interaction of Au16 Nanocluster with Defects in Supporting Graphite: A Density-Functional Study
2011
Soft-landed adsorption of Au-16 on bilayered graphene is investigated using density functional theory. The orientation of the Au-16 cluster and number of neighboring surface vacancies affect the overall structural and electronic properties of the cluster. The results of the PBE, vdW-DF, and vdW-DF2 exchange-correlation functionals are compared for the cluster-substrate interaction for systems with and without defects. In the presence of defects size two and greater, an Au atom adsorbs into the topmost graphene layer; this strongly influences the binding energy (>3 eV), while inducing substantial bending in the carbon plane and altering electronic properties of the system. Though the T-d-sym…