Search results for " affinity"
showing 10 items of 188 documents
Theoretical Determination of the Singlet → Singlet and Singlet → Triplet Electronic Spectra, Lowest Ionization Potentials, and Electron Affinity of C…
2003
The singlet → singlet and singlet → triplet electronic spectra of cycloocta-1,3,5,7-tetraene are studied using multiconfigurational second-order perturbation theory (CASPT2) and extended atomic natural orbitals (ANOs) basis sets. The observed dipole-allowed features at 4.43, 6.02, and 6.42 eV and the spin-forbidden singlet → triplet bands with maxima at 3.05, 4.05, and 4.84 eV (Frueholz, R. P.; Kuppermann, A. J. Chem. Phys. 1978, 69, 3614) are assigned as the transitions 1 1 A 1 → 1 1 A 2 , 1 1 A 1 → 2 1 B 2 (3p z ), 1 1 A 1 → 3 1 E, and 1 1 A 1 - 1 3 A 2 , 1 1 A 1 → 1 3 E, 1 1 A 1 → 1 3 B 1 , respectively. The lowest (3s) Rydberg singlet and triplet states are placed at 5.58 (2 1 A 1 ) and…
Cytotoxic effects of antibodies to proteinase 3 (C-ANCA) on human endothelial cells.
1994
SUMMARY Autoantibodies directed against cytoplasmic antigens of neutrophils (ANCA), especially those with specificity for proteinase 3 (PR-3) and myeloperoxidase, are valuable markers for differential diagnosis and monitoring of disease activity in Wegener's granulomatosis (WG) and other vasculitides. Till now, several concepts concerning a direct role of antibodies against PR-3 in the pathogenesis of WG have been discussed. Recently we were able to show that these antibodies recognize PR-3 translocated into the membrane of human endothelial cells. The aim of this study was to investigate putative cytotoxic effects of antibodies to PR-3 on human endothelial cells. Antibodies were obtained b…
Novel σ1 antagonists designed for tumor therapy: Structure – activity relationships of aminoethyl substituted cyclohexanes
2021
Abstract Depending on the substitution pattern and stereochemistry, 1,3-dioxanes 1 with an aminoethyl moiety in 4-position represent potent σ1 receptor antagonists. In order to increase the stability, a cyclohexane ring first replaced the acetalic 1, 3-dioxane ring of 1. A large set of aminoethyl substituted cyclohexane derivatives was prepared in a six-step synthesis. All enantiomers and diastereomers were separated by chiral HPLC at the stage of the primary alcohol 7, and their absolute configuration was determined by CD spectroscopy. Neither the relative nor the absolute configuration had a large impact on the σ1 affinity. The highest σ1 affinity was found for cis-configured benzylamines…
Impact of a Three Amino Acid Deletion in the CH2 Domain of Murine IgG1 on Fc-Associated Effector Functions
2008
Abstract Four murine IgG subclasses display markedly different Fc-associated effector functions because of their differential binding to three activating IgG Fc receptors (FcγRI, FcγRIII, and FcγRIV) and C1q. Previous analysis of IgG subclass switch variants of 34-3C anti-RBC monoclonal autoantibodies revealed that the IgG1 subclass, which binds only to FcγRIII and fails to activate complement, displayed the poorest pathogenic potential. This could be related to the presence of a three amino acid deletion at positions 233–235 in the CH2 domain uniquely found in this subclass. To address this question, IgG1 insertion and IgG2b deletion mutants at positions 233–235 of 34-3C anti-RBC Abs were …
Analysis of LSD in human body fluids and hair samples applying ImmunElute columns.
2000
Immunoaffinity extraction units (LSD ImmunElute) are commercially available for the analysis of lysergic acid diethylamide (LSD) in urine. The ImmunElute resin contains immobilized monoclonal antibodies to LSD. We applied the ImmunElute procedure to serum and also to human hair samples. For hair analysis the samples were first extracted with methanol under sonication. The extracts were then purified using the ImmunElute resin. LSD analysis was carried out with HPLC and fluorescence detection. The immunoaffinity extraction provides highly purified extracts for chromatographic analysis. The limit of detection (signal-to-noise ratio = 3) has been determined to be < 50 pg regardless of which sa…
Immunochromatographic Assay for Quantitation of Milk Progesterone.
1996
We describe a rapid immunochromatographic method for the quantitation of progesterone in bovine milk. The method is based on a 'competitive' assay format using the monoclonal antibody to progesterone and a progesterone-protein conjugate labelled with colloidal gold particles. The monoclonal antibody to progesterone is immobilized as a narrow detection zone on a porous membrane. The sample is mixed with colloidal gold particles coated with progesterone-protein conjugate, and the mixture is allowed to migrate past the detection zone. Migration is facilitated by capillary forces. The amount of labelled progesterone-protein conjugate bound to the detection zone, as detected by photometric scann…
Separation of plasma membrane proteins of cultured human fibroblasts by affinity chromatography on bonded microparticulate silicas.
1984
Abstract Adsorbents for high-performance affinity chromatography were prepared by bonding proteins and reactive Procion triazine dyes to 3-isothiocyanatopropyl- and 3-aminopropylsilicas. The materials prepared were used successfully in the separation of hydrophobic plasma membrane proteins of cultured human fibroblasts. The data obtained show that the reaction of 3-isothiocyanatopropyltriethoxysilane (ITCPS) with the surface hydroxyl groups of silica yields a new and convenient route to preparing an “activated carrier” that is capable of coupling with potential affinity ligands containing amino functional groups. The reaction and bonding procedures of 3-isothiocyanatopropyltriethoxysilane a…
Novel group A rotavirus G8 P[1] as primary cause of an ovine diarrheic syndrome outbreak in weaned lambs
2011
International audience; Rotavirus is a worldwide major cause of diarrhea outbreaks in neonatal ruminants. An outbreak of ovine diarrheic syndrome (ODS) in 50-75 days-old lambs (weaned lambs) is described. Fecal immunochromatography and intestinal immunohistochemistry for rotavirus group A were performed. In addition, semi-nested multiplex RT-PCR for G and P rotavirus genotyping in combination with sequencing were performed, to support the diagnosis and identify the viral strain. A novel ovine rotavirus group A G8 P[1] strain was determined as the main cause of the ODS observed, whereas other pathogens were ruled out.
Dual-affinity avidin molecules
2005
A recently reported dual-chain avidin was modified further to contain two distinct, independent types of ligand-binding sites within a single polypeptide chain. Chicken avidin is normally a tetrameric glycoprotein that binds water-soluble d-biotin with extreme affinity (Kd ≈ 10−15M). Avidin is utilized in various applications and techniques in the life sciences and in the nanosciences. In a recent study, we described a novel avidin monomer-fusion chimera that joins two circularly permuted monomers into a single polypeptide chain. Two of these dual-chain avidins were observed to associate spontaneously to form a dimer equivalent to the wt tetramer. In the present study, we successfully used …
Microseparation techniques for the study of the enantioselectivity of drug-plasma protein binding.
2009
Stereoselectivity in protein binding can have a significant effect on the pharmacokinetic and pharmacodynamic properties of chiral drugs. The investigation of enantioselectivity of drugs in their binding with human plasma proteins and the identification of the molecular mechanisms involved in the stereodiscrimination by the proteins represent a great challenge for clinical pharmacology. In this review, the separation techniques used for enantioselective protein binding experiments are described and compared. An overview of studies on enantiomer–protein interactions, enantiomer–enantiomer interactions as well as chiral drug–drug interactions, including allosteric effects, is presented. The c…