Search results for "Horseradish Peroxidase"
showing 10 items of 42 documents
Hole burning and pressure phenomena in chromoproteins
1993
Abstract We investigated the behavior of spectral holes under pressure at various frequencies within the inhomogeneous band for two proteins, namely myoglobin and horseradish peroxidase. In order to achieve narrow bandwidth hole burning, the heme chromophore was replaced by protoporphyrin IX and mesoporphyrin IX, respectively. In myoglobin, we found that the pressure induced shift of the holes varied in a strongly non-linear fashion, when the burn-frequency was tuned across the absorption band. In horseradish peroxidase the pressure shift was linear with burn-frequency but changed in a dramatic fashion upon complex formation with a substrate molecule. These observations are interpreted with…
Redox intermediates of plant and mammalian peroxidases: a comparative transient-kinetic study of their reactivity toward indole derivatives.
2002
Abstract A comparative study on the reactivity of five indole derivatives (tryptamine, N-acetyltryptamine, tryptophan, melatonin, and serotonin), with the redox intermediates compound I (k2) and compound II (k3) of the plant enzyme horseradish peroxidase (HRP) and the two mammalian enzymes lactoperoxidase (LPO) and myeloperoxidase (MPO), was performed using the sequential-mixing stopped-flow technique. The calculated bimolecular rate constants (k2, k3) revealed substantial differences regarding the oxidizability of the substrates by redox intermediates at pH 7.0 and 25°C. With HRP it was shown that k2 and k3 are mainly determined by the reduction potential (E°′) of the substrate with k2 bei…
Septal complex of the telencephalon of lizards: III. Efferent connections and general discussion.
1998
The projections of the septum of the lizard Podarcis hispanica (Lacertidae) were studied by combining retrograde and anterograde neuroanatomical tracing. The results confirm the classification of septal nuclei into three main divisions. The nuclei composing the central septal division (anterior, lateral, medial, dorsolateral, and ventrolateral nuclei) displayed differential projections to the basal telencephalon, preoptic and anterior hypothalamus, lateral hypothalamic area, dorsal hypothalamus, mammillary complex, dorsomedial anterior thalamus, ventral tegmental area, interpeduncular nucleus, raphe nucleus, torus semicircularis pars laminaris, reptilian A8 nucleus/ substantia nigra and cen…
Olfacto-retinalis pathway in Austrolebias charrua fishes: A neuronal tracer study
2013
Abstract The olfacto-retinal centrifugal system, a constant component of the central nervous system that appears to exist in all vertebrate groups, is part of the terminal nerve (TN) complex. TN allows the integration of different sensory modalities, and its anatomic variability may have functional and evolutionary significance. We propose that the olfacto-retinal branch of TN is an important anatomical link that allows the functional interaction between olfactory and visual systems in Austrolebias . By injecting three different neuronal tracers (biocytin, horseradish peroxidase, and 1,1′-dioctadecyl-3,3,3′,3′tetramethyl-indocarbocyanine perchlorate (DiI)) in the left eye of Austrolebias ch…
Time sequence and site of fluid accumulation in experimental neurogenic pulmonary edema.
1976
The initial phase of pulmonary edema development following intracranial pressure elevation was studied by means of transmission electron microscopy. Using perfusion fixation and application of a blood tracer (HRP horseradish peroxidase) the time sequence and site of fluid leakage out of pulmonary vessels was demonstrated: - passage of edema fluid through intercellular clefts of alveolar capillary endothelium - edema accumulation in alveolar interstitial tissue - draining of edema fluid from the alveolar septum to the interstitium of terminal bronchioli and to lymphatic vessels. An early interepithelial fluid leakage out of the alveolar wall remains questionable.
Ascending projections from the optic tectum in the lizard Podarcis hispanica.
1998
The ascending projections of the optic tectum, including their cells of origin, have been studied in the lizard Podarcis hispanica by means of a two-step experimental procedure. First, tracers were injected in the tectum to study the anterograde labeling in the forebrain. Second, the cells of origin of these projections have been identified by analyzing the retrograde labeling after tracer injections in the thalamus, hypothalamus, and pretectum. Three main tectal ascending pathways have been described: the dorsal tecto-thalamic tract (dtt), the medial tecto-thalamic tract (mtt), and the ventral tecto-thalamic tract (vtt). The dtt originates in radial cells of layers 5 and 7 and bipolar cell…
Direct projections to the rat pineal gland via the stria medullaris thalami. An anterograde tracing study by use of horseradish peroxidase.
1986
The possible presence of a direct nervous projection from the paraventricular nucleus (PVN) of the hypothalamus to the pineal gland of the rat was investigated by means of the anterograde neuron-tracing method using horseradish peroxidase. The tracer was injected unilaterally into the PVN and the animals were allowed to survive between 12 and 26 h. Numerous peroxidase-positive fibers were observed, ipsilateral to the injection site, in the stria medullaris thalami and could be followed into the medial habenular nucleus and the habenular commissure. From there, fibers penetrated into the deep pineal gland (lamina intercalaris), and further into the pineal stalk. These data support results of…
Contact sensitizers modulate mechanisms of receptor-mediated endocytosis but not fluid-phase endocytosis in murine epidermal Langerhans cells.
1995
In order to define the influence of contact allergens on the fluid-phase endocytosis (FPE) of soluble molecules of murine epidermal Langerhans cells (LC), we studied the internalization of FITC-labeled bovine serum albumin (FITC-BSA), TRITC-labeled dextrane (TRITC-DEX) as well as horseradish peroxidase by LC. A 3-parameter flow-cytometric technique was performed for quantification of internalized FITC-BSA in LC using quantum red-labeled reagents for detection of la-antigen expression by LC and propidium iodide for exclusion of dead cells from analysis. A temperature-dependent rapid accumulation of FITC-BSA was noticed in time-course studies reaching a plateau between 1 and 2 h of in vitro c…
Tuning protein adsorption on graphene surfaces via laser-induced oxidation
2021
An approach for controlled protein immobilization on laser-induced two-photon (2P) oxidation patterned graphene oxide (GO) surfaces is described. Selected proteins, horseradish peroxidase (HRP) and biotinylated bovine serum albumin (b-BSA) were successfully immobilized on oxidized graphene surfaces, via non-covalent interactions, by immersion of graphene-coated microchips in the protein solution. The effects of laser pulse energy, irradiation time, protein concentration and duration of incubation on the topography of immobilized proteins and consequent defects upon the lattice of graphene were systemically studied by atomic force microscopy (AFM) and Raman spectroscopy. AFM and fluorescence…
Specific release of membrane-bound annexin II and cortical cytoskeletal elements by sequestration of membrane cholesterol
1997
Annexin II is an abundant protein which is present in the cytosol and on the cytoplasmic face of plasma membrane and early endosomes. It is generally believed that this association occurs via Ca(2+)-dependent binding to lipids, a mechanism typical for the annexin protein family. Although previous studies have shown that annexin II is involved in early endosome dynamics and organization, the precise biological role of the protein is unknown. In this study, we found that approximately 50% of the total cellular annexin was associated with membranes in a Ca(2+)-independent manner. This binding was extremely tight, since it resisted high salt and, to some extent, high pH treatments. We found, h…