Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.11.1.7 (peroxidase)
65,474 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Iodinated cell surface components from human thymus lymphocytes labeled by the lactoperoxidase method, were solubilized by papain digestion and then 3 M KCl extraction of the residual cell pellet. Antiserum to human thymus bound three components from this material, mol. wt. approximately equal to 40 000, 20 000 and 12 000 daltons. This antiserum was absorbed with cultured human lymphoblasts (CHL) until it no longer bound CHL antigens or the HLA-beta 2-microglobulin complex. It continued to bind labeled antigens from thymus, peripheral blood lymphocytes and "T" cell-enriched fraction of tonsil lymphocytes. The absorbed antiserum bound a component from papain-solubilized thymus antigens which had an estimated molecular weight of approximately 40 000 daltons and which was not associated with beta 2-microglobulin. This component seemed to be a human T cell-specific antigen.
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PMID:Isolation of lymphocyte surface antigens. II. Identification of non-beta 2 -microglobulin-associated human T cell-specific antigen. 6 42

A fluorescein isothiocyanate (FITC) technique and one based on peroxidase-antiperoxidase (PAP) were used to study the distribution of immunoglobulin (Ig) in cryostat and paraffin sections of human tonsil. Trypsin and other proteolytic enzymes were used to 'unmask' the antigen in paraffin sections. The effects of processing, and particularly of fixation, on the immunohistochemical response of tissues were studied. The FITC and PAP methods detected Ig in paraffin and cryostat sections equally well. The distribution of the antigen was the same with both methods but the PAP method was the more informative. Formaldehyde-sucrose solution proved more suitable for fixing tissues for immunohistochemistry than glutaraldehyde. Trypsin revealed antigen in parraffin sections more efficiently than pepsin, papain, or pronase. Surface Ig (s-Ig) could be demonstrated in trypsinised paraffin sections but less effectively than in cryostat sections. Trypsinised paraffin sections were, however, more suitable for intracellular Ig (c-Ig) than cryostat sections although the performance of cryostat sections could be improved by prior fixation with a coagulative fixative.
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PMID:Demonstration of immunoglobulin in cryostat and paraffin sections of human tonsil by immunofluorescence and immunoperoxidase techniques. Effects of processing on immunohistochemical performance of tissues and on the use of proteolytic enzymes to unmask antigens in sections. 36 59

Mannose-binding hemagglutinins were found in the extracts of a pyocyanin-forming Pseudomonas aeruginosa, which contain galactose-specific hemagglutinins. They were purified simultaneously with the latter proteins by heating to 70 degrees C, precipitating with ammonium sulfate, application to a Sepharose 4B column, and elution from it by 0.05 M mannose. The mannose-specific hemagglutinins were shown to be similar to the galactophilic ones in (a) being glycoproteins of very low molecular weight (about 11 000 by SDS gel electrophoresis), (b) their tendency to aggregate, and (c) their ability to effect stronger agglutination of erythrocytes treated with papain than of untreated ones. They were found to resemble them also in their reaction with simple sugars and interactions with divalent cations, which are essential for their activity. In these properties, as well as in their relative resistance to heat and to proteolytic enzymes, these two types of bacterial hemagglutinins are like most of the plant, contrasted with the animal, hemagglutinins. The reactions with mannose and mannose-bearing compounds (yeast mannan, horseradish peroxidase (EC 1.11.1.7), and serum globulins), which are not shared with the galactophilic Pseudomonas hemagglutinins, indicate a relationship of the mannose-binding protein of Pseudomonas to the plant lectin concanavalin A. The mannose-binding hemagglutinins do not exhibit identical cell-agglutinating spectra owing to difference in profiles of sugar specificity and relative affinity to mannose derivatives compared with free mannose.
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PMID:Mannose-binding hemagglutinins in extracts of Pseudomonas aeruginosa. 40 63

Proteolysis of reconstituted membranes with papain and thermolysin reveals the existence of two rhodopsin populations: one susceptible to proteolysis and the other protected. The susceptible population corresponds to rhodopsin molecules with the same orientation as rhodopsin in the native membrane, while the protected population corresponds to "inverted" rhodopsin molecules only found in reconstituted membranes. Using an iodination enhancement probe, we demonstrate that lactoperoxidase catalyzes iodination of rhodopsin exclusively on the external surface of these sealed reconstituted vesicles. Furthermore, we find that both rhodopsin populations in reconstituted membranes (normal and inverted) are readily iodinated by lactoperoxidase, providing definitive evidence that the rhodopsin polypeptide spans the membrane thickness. Additional conclusions from these experiments are discussed in terms of a model for the folding of the rhodopsin polypeptide in the membrane.
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PMID:Organization of rhodopsin in photoreceptor membranes. 2. Transmembrane organization of bovine rhodopsin: evidence from proteolysis and lactoperoxidase-catalyzed iodination of native and reconstituted membranes. 71 47

Topochemical characteristics of reactions of different types of collagen-containing structures with Concanavalin A (Con A) have not been considered up to now. In this study the presence and availability of glucose residues of collagen molecules from intestine, liver, cartilage and tendon are detected using Con A and horseradish peroxidase (HRP). In intestine, cartilage and tendon sections, the Con A-HRP method was only significantly positive when the sections were first submitted to treatment with papain. This suggested the presence of glycoproteins and proteoglycans of the extracellular matrix (ECM), which might interfere either interacting with lateral sugar residues of the collagen molecules, or causing some steric blockade or even masking as occurs in regions with a high state of compactness.
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PMID:Interaction of concanavalin A with sugar residues of collagen from different tissues. 209 54

Human leucocyte elastase (HLE) cleaves IgG into Fab and Fc fragments. The Fc fragment bears an elastase-specific antigen and has previously been reported to be found in synovial fluid during rheumatoid arthritis. In addition, biological activity of elastase-specific Fc fragments has been described in modulating granulocyte oxidative metabolism. To investigate further regulatory effects of the elastase-induced IgG cleavage products, we tested the elastase and myeloperoxidase release of granulocytes. IgG fragments induce no enzyme release of unstimulated neutrophils. But elastase and myeloperoxidase release of cytochalasin b/FMLP-treated neutrophils is stimulated in a dose-dependent manner by the Fab fragments. The extent of stimulation depends on stimulus concentration and is at its maximum for low (e.g. 2.5 x 10(-8) M) FMLP concentration. Ten nanomoles Fab/4 x 10(6) PMN augment elastase release to 206% and myeloperoxidase release to 155% after pre-stimulation with 2.5 x 10(-8) M FMLP. Fc fragments stimulate elastase release to 162% but no MPO release. Untreated IgG1 and analog Fab and Fc fragments produced by papain cleavage react similarly. Elastase-generated IgG fragments may therefore up-regulate their concentration by simulating elastase release. The concomitantly stimulated release of myeloperoxidase may influence bactericidal activity and termination of oxidative burst.
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PMID:Stimulation of neutrophil elastase and myeloperoxidase release by IgG fragments. 216 86

The monoclonal antibody designated LN-1 was used in an attempt to identify the antigen in follicular center cell lymphomas using tissue sections fixed in formalin. The LN-1 antibody has been shown in previous studies to identify follicular center cells and give reproducible results in tissue fixed in B5. We used the ABC peroxidase technique to examined formalin-fixed, paraffin embedded sections representing 52 cases of various histologic subgroups of non-Hodgkin's lymphomas based upon the Lukes-Collins classification. Following immunostaining with LN-1 using overnight incubation of the antibody and papain treated sections, 37 cases, and all of the 38 cases previously diagnosed as follicular center cell lymphomas, gave a positive reaction to the LN-1 monoclonal antibody.
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PMID:Immunohistochemical analysis of non-Hodgkin's lymphomas with the monoclonal antibody to follicular center lymphocytes reactive in paraffin sections. 266 10

The hybridoma, 62H3, which secretes a monoclonal IgG2b with anti-HLA-DR specificity, was expanded in pristane-primed BALB/c mice and the antibody was isolated from the ascitic fluid by affinity chromatography on Protein A-Sepharose. The purified IgG2b antibody was tested by an enzyme immunoassay for antibody activity against a panel of 40 self and non-self antigens. It was found to react strongly with beta-galactosidase, actin, glutamate dehydrogenase, rabbit and human IgG and di- and trinitrophenyl groups; and moderately with tubulin, insulin and phosphorylcholine; but it did not react with various other self and non-self antigens, such as DNA, albumin, keyhole limpet hemocyanin, hen lysozyme and horseradish peroxidase. Fab and Fc fragments were prepared from this IgG2b by papain proteolysis. The Fab fragment possessed the same spectrum of polyreactivities as the native IgG2b, whereas no activity was detected with the Fc fraction. In order to investigate the properties of the antigen binding site, the actin, TNP and rabbit IgG antibody activities were studied in more detail by enzyme immunoassay, Western blot and immunocytochemistry. The monomolecular nature of this multireactivity was confirmed by immunoabsorption analysis. Furthermore, 62H3 monoclonality was also verified by comparative isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis with other monospecific antibodies. The dissociation constants (Kd) of antigen-antibody equilibria in solution were measured. The Kd for actin was 1.11 +/- 0.24 x 10(-5) M and the Kd for TNP-BSA was 8.7 +/- 0.51 x 10(-7) M. No interaction with rabbit IgG could be detected in solution. These findings raise the question of the possible implication in autoimmune pathology or in normal physiology of IgG class polyspecific antibodies with solid-phase restricted cross-reactive rheumatoid factor activity.
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PMID:Immunochemical studies of a murine polyreactive IgG2b autoantibody with rheumatoid factor activity. 277 Jul 48

The reaction of lysine with dithioesters was applied to horseradish peroxidase donor: hydrogen-peroxide oxidoreductase, EC 1.11.1.7) using carboxymethyl dithiotridecanoate: three to four lysine residues were modified. The modified enzyme was soluble and active in diethyl ether. Papain (EC 3.4.22.2) was modified with carboxymethyl dithiobenzoate: two lysine residues were modified. The modified enzyme was soluble and active in dimethylsulfoxide. From these results it is concluded that dithioesters are efficient reagents for the modification of peripheral lysine residues of proteins. Aromatic dithioesters, less reactive but more selective, should be recommended for thiol-dependent enzymes such as papain.
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PMID:Application of the reaction of dithioesters with epsilon-amino groups in lysine to the chemical modification of proteins. 314 23

1. We have begun to analyze neurotransmitter-activated conductances in retinal ganglion cells by measuring the response of single voltage-clamped adult goldfish ganglion cells to gamma-aminobutyric acid (GABA). Here we describe 1) our method of identifying ganglion cells in vitro after their dissociation from papain-treated retinas, and 2) the response of these cells to GABA in the tight-seal whole cell configuration of the patch-clamp method (cf. 41) after 1-4 days of primary cell culture. 2. Ganglion cell somata were backfilled in situ by injections of horseradish peroxidase (HRP) into the optic nerve. After dissociation of the retinas containing these cells, HRP reaction product was localized to cells that retained the size, shape, and an intracellular organelle characteristic of ganglion cells in situ. These features enabled us thereafter to identify ganglion cells in vitro without retrograde marker transport. 3. GABA (3-10 microM) elicited inward currents and substantial noise increases in almost all ganglion cells at negative holding potentials. Reversal potential measurements in salines containing different chloride concentrations indicated that GABA produces a chloride-selective conductance increase in ganglion cells. Bicuculline (10 microM) reversibly inhibited ganglion cell GABA responses. Baclofen (10 microM) alone elicited no responses in ganglion cells. 4. Noise analysis of GABA-activated whole cell currents yielded elementary conductance estimates of 16 pS, with a slow time constant of 30 ms plus a faster component of 1-2 ms. No significant voltage dependence of these values was observed between -20 and -80 mV. 5. We have thus devised a means of identifying ganglion cells dissociated from adult retinas, identified GABAA receptors (cf. 16) on these cells, and found that the responses mediated by these receptors resemble those found in other regions of central nervous system (CNS). These results are consistent with the notion that GABA may function as an inhibitory transmitter at synapses on ganglion cells.
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PMID:GABA-activated whole-cell currents in isolated retinal ganglion cells. 317 34


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