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

---

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

The role of oestradiol-17 beta in the induction of specific cytosolic receptors for 1 alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3) was examined in the immature rat uterus. An acrylamide gel electrophoretic analysis was developed to separate the specific receptor for 1,25(OH)2D3 from the plasma binding protein for vitamin D3 metabolites. Employing this sensitive method the presence of receptors for 1,25(OH)2D3 in the mature rat uterus was evident. Such receptors were not found in the uterus of saline-treated immature rats. However, oestradiol administration caused an induction of these receptors in the immature rat uterus, together with a significant increase in the uterine weight, progesterone receptor level and peroxidase activity. These results suggest a mechanism for oestradiol regulation of calcium metabolism in the uterus at times of high demand for this cation during the gestation period.
...
PMID:Induction of cytosolic receptors for 1 alpha, 25-dihydroxyvitamin D3 in the immature rat uterus by oestradiol. 632 24

To demonstrate antigens in cultured human tumor cells recognized by antibodies in human sera, extracts of cultured malignant melanoma cells were separated by SDS-PAGE, and electrophoretically transferred to nitrocellulose paper (NCP). The resulting electroblots were incubated with human serum, and bound immunoglobulin (Ig) was visualized with rabbit antibodies specific for human IgG, IgA or IgM, followed by peroxidase-conjugated goat anti-rabbit IgG. Antigen-antibody reactions in the nitrocellulose paper were also detected using 125I-labeled anti-rabbit IgG. As little as 125 pg of bound antibody per band were detectable. The numbers of proteins recognized by antibodies in human sera depended both on the quantity of protein transferred and the concentration of Ig applied to the NCP. Whole serum could not be used at dilutions less than or equal to 1:20 without an unacceptable increase in background staining. Binding of Ig to tumor cell proteins transferred to NCP depended on interactions with the Fab', not the Fc region of the Ig molecule. To determine the efficiency of transfer as a function of both time and molecular weight, tumor cell proteins were intrinsically labeled with 75Se-labeled methionine and transferred for up to 4 h after fractionation in gels containing acrylamide concentrations of 5%, 7.5%, 10% or 12%. Proteins less than 150 kDa were transferred with particularly high efficiency in greater than or equal to 2 h. Different antigens were recognized by the IgA, the IgG and the IgM molecules from the same sera. The methods outlined herein are proving to be useful in monitoring the purification of specific antigens from whole tumor cell extracts.
...
PMID:Use of human antibodies to identify antigens in cultured human tumor cells: detection of discrete antigen molecules using electroblotting and enzyme-linked antibody probes. 635 16

An enzyme-linked immunosorbent assay was developed to enumerate Treponema pallidum cells. The assay could detect from 2 X 10(7) to 4 X 10(8) treponemes per ml. Reactive rabbit serum and goat anti-rabbit immunoglobulin G (peroxidase conjugate) were used in the assay. Optimum results were obtained when 2,2'-azino-di(ethylbenzthiazolinesulfonic acid) was used as the dye for the enzyme reaction and the reactions were allowed to run for 45 min. Interestingly, assays in which in vivo-cultivated T. pallidum was used produced lower absorbance values than those in which T. pallidum was cultivated in vitro.
...
PMID:Enumeration of Treponema pallidum cells cultivated in vitro by an enzyme-linked immunosorbent assay. 636 89

A protein antigen, I/II, was purified from cells and culture supernatants of Streptococcus mutans (serotype c) by solubilization in urea followed by ion exchange chromatography and gel filtration. Immunological activity was retained after further purification by preparative sodium dodecyl sulphate--polyacrylamide gel electrophoresis (SDS--PAGE). The sedimentation coefficient was estimated to be approximately 8.7S by sucrose gradient centrifugation. The use of staining procedures, as well as the linear migration of this protein through different concentrations of acrylamide during SDS--PAGE, indicated that the antigen is probably not a glycoprotein. A lower molecular weight protein containing the free antigen I determinant was shown to have extensive homology with intact antigen I/II which implied that the former was a degradation product of the intact 185 000 dalton antigen I/II. Antigen II, although previously defined by its resistance to proteases, could be further digested with trypsin after denaturation by SDS--PAGE. Antigen I/II could not be correlated with a group of glucosyltransferases isolated from whole cells and culture supernatants. The cell surface location of antigen I/II was established by the lactoperoxidase-catalysed iodination of intact cells followed by protein analysis using SDS--PAGE. Previously, the potential importance of antigen I/II has been established by its immunogenicity and capacity to induce a protective immune response against dental caries.
...
PMID:Separation and characterization of a protein antigen from cells of Streptococcus mutans. 645 27

A new technique of visualization of diffusion-convection phenomena at a solid-liquid interface using the luminol chemiluminescent reaction catalyzed by immobilized peroxidase has been previously described (Dimicoli, J.L., M. Nakache, and P. Peronneau, 1982, Biorheology, 19:281-300). We propose now a theoretical model that predicts quantitatively the light fluxes, JL, corresponding to the transfer J of the hydrogen peroxide substrate at the liquid-solid interface in a cylindrical tube for continuous flow experiments. A simple phenomenological relation, J alpha J1/mL (1 less than m less than 3) was first established for each point of the wall. Then, numerical integration showed that, independent of the laminar or turbulent character of the flow, J1/mL was proportional to (S1 Kideal)/(1 + Kideal/ET), where S1 is the bulk substrate concentration, Kideal is the ideal transport coefficient, and ET (in cm.S-1) a phenomenological first-order enzymatic rate constant per unit of wall surface. This relation proved to be satisfactory for all experimental conditions since a single mean value of ET takes into account the experimental data collected for a given enzymated tube in a large range of Reynolds number values (Re) (500 less than Re less than 9,000) and of distances from the entrance of the tube (chi greater than 0.3 cm). This quantitative analysis using a pseudo-first-order approximation interprets the observed great dependence of JL on Re(JL alpha Ren', with n' usually greater than 1/3 for laminar flows) and on S1 (JL alpha S1m). It predicts also that the laminar-to-turbulent transition can be evidenced for interfacial enzymatic activity, ET greater than 2.10(-4) cm.S-1, as observed with most of the tubes prepared by covalent binding of peroxidase on the acrylamide gel wall. The experiment had to be carried out at a pH value of 8, which corresponds to the fastest rate of the chemiluminescent reaction. The predicted entrance effects were also observed experimentally for the first time in an immobilized enzyme system. This technique appears therefore to be a valuable tool for the quantitative analysis of diffusion-convection phenomena at a liquid-solid interface with a good spatial resolution with a great range of flow rate.
...
PMID:Topological analysis of wall mass transport using a luminescent immobilized enzymatic system. 648 35

The inducing effects of chronic ethanol ingestion on hepatic monooxygenases in Sprague-Dawley and Long-Evans rats, and A/J and C57BL/6J mice, were studied. Cytochrome P-450 content was significantly increased in livers of all animals receiving the experimental ethanol-containing liquid diet. The CO-difference spectra of microsomes from ethanol-treated animals showed a shift in the absorbance maximum to 451-452 nm, compared to the absorbance maximum of 450 nm observed with microsomes from control animals. Ethylmorphine N-demethylase and benzo[a]pyrene hydroxylase activities in livers of ethanol-treated animals were minimally affected. The shift in the absorbance maxima to longer wavelengths in the CO-difference spectrum and the minimal effects on the metabolism of ethylmorphine and benzo[a]pyrene demonstrate that ethanol differs in its inducing properties, when compared to the properties of the two widely used hepatic microsomal enzyme inducers, phenobarbital and 3-methylcholanthrene. In contrast to the minimal effects observed on the metabolism of ethylmorphine and benzo[a]pyrene, several fold increases were observed in hepatic 7-ethoxycoumarin 0-deethylase and aniline hydroxylase activities in the treated animals. Polyacrylamide gel electrophoresis of hepatic microsomes from those animals receiving ethanol revealed protein band(s) in the cytochrome P-450 molecular weight region, the intensities of which were markedly increased relative to that from control animals. The heme-associated peroxidase activity was also increased in the same molecular weight region. The results of the present spectral, catalytic, and electrophoretic studies demonstrate that in mice, as in rats, chronic ethanol treatment causes the induction of specific cytochrome(s) P-450 with preferential activity toward aniline and 7-ethoxycoumarin.
...
PMID:Comparative effects of ethanol administration on hepatic monooxygenases in rats and mice. 654 73

The extent of neuronal labelling with horseradish peroxidase (HRP) was examined in rat trigeminal motor neurons at various stages of acrylamide intoxication, following HRP uptake by motor nerve endings in the anterior digastric muscle. After 7 days of acrylamide (5 daily injections of 30 mg acrylamide/kg body weight), the pattern of HRP labelling was altered from normal, and this changed pattern persisted without further alteration when survival time and dosage were increased to 14 and 21 days (equivalent to 10 X 30 mg/kg and 15 X 30 mg/kg respectively). Six hours after HRP injection, the number of labelled cells in the ipsilateral trigeminal motor nucleus was reduced in treated animals compared to controls. By 18 hours, cells containing label were present in similar numbers to controls; but by 24 hours, the number in treated animals had fallen again, unlike controls in which labelling remained constant between 6 and 24 hours. At longer intervals, this reduction in labelling continued, but more slowly, so that by 96 hours after HRP injection, numbers of labelled cells were again similar in poisoned and control animals. One and three days after a single intramuscular injection of 0.05 microgram botulinum toxin type A, HRP labelling in the trigeminal motor neurons was unaffected, although at three days after toxin, mild chromatolytic changes could be seen in a few of the neurons.
...
PMID:Effects of acrylamide and botulinum toxin on horseradish peroxidase labelling of trigeminal motor neurons in the rat. 665 40

Environmentally induced flax genotrophs L and S show heritable shifts in the relative mobilities of peroxidase, esterase, and acid phosphatase isozymes, plus a number of nonspecific glycoproteins. All L isozymes migrated faster than corresponding S isozymes in 10% acrylamide gels. Various aspects of these shifts are reviewed here; it is proposed that posttranslational modification, probably of the carbohydrate moieties of these glycoproteins, underlies the shifts. This proposal is discussed in relation to the switch model for genotroph induction.
...
PMID:Possible posttranslational modification, and its genetic control, in flax genotroph isozymes. 671 90

The preparation and characterization of a horseradish peroxidase-rabbit antiperoxidase Fab immunocomplex (HRP-Fab2) useful for immunocytochemical localization of primary tissue-bound rabbit antibody are described. Antisera with titer to horseradish peroxidase (HRP) were raised in rabbits. Anti-HRP-Fab fragments were prepared by controlled mercuripapain digestion of the purified rabbit IgG. The complex was formed during incubation of Fab fragments with HRP, and fractions containing HRP activity that were precipitable by goat anti-rabbit IgG serum were isolated by gel filtration. The major isolated complex had a molecular weight of approximately 150,000 daltons and migrated as a single band on cellulose acetate electrophoresis. Polyacrylamide gel electrophoresis in SDS indicated the major polypeptide components of the complex were HRP and Fab. RZ (absorbance at 403 nm/275 nm) determination indicated a molar ratio of 2 Fab:1 HRP. The complex was stable for at least 1 year at -20 degrees C and was used successfully in a number of immunocytochemical procedures.
...
PMID:Preparation and characterization of peroxidase: antiperoxidase-Fab complex. 676 53

The protein composition and architecture of the photosynthetic membranes from the cyanobacterium, Synechococcus cedrorum, were analyzed with the aid of site-specific labels. Using membranes labeled with 35S, about 50 membrane proteins can be detected by sodium dodecyl sulfate acrylamide gel electrophoresis. Approximately half of the proteins are accessible to modification by the impermeant probe, lactoperoxidase, indicating that they have surface-exposed domains. At least six of these external proteins can be removed by EDTA washing; the correspondence in molecular weights between five of these EDTA-extractable proteins and those of typical chloroplast coupling factor preparations may indicate that they are subunits of a membrane-bound ATPase. The photoactive, lipophilic compound, [125I]iodonaphthyl azide, was used to label protein domains in contact with the lipid bilayer. Iodonaphthyl azide modification led to a labelling pattern significantly different from that seen with lactoperoxidase. In particular, proteins in the 13000--20000 dalton range that were labeled poorly or not at all by lactoperoxidase were heavily modified by iodonaphthyl azide. Photosystem I and II particles, extracted from the membrane by digitonin treatment, were iodinated by lactoperoxidase after isolation. The PS I particles acted as a relatively tight complex, with most of the proteins remaining inaccessible to surface modification. The PS II particles, on the other hand, responded as a more open structure, with most of the subunits yielding to lactoperoxidase iodination. Similar studies on a highly fluorescent, temperature-sensitive mutant of S. cedrorum revealed a different organization of the PS II complex. This mutant, when grown at 40 degrees C, inserts a 51 kdalton polypeptide in place of a 53 kdalton protein. This protein also replaces the 53 kdalton species in the PS II complex of the mutant after 40 degrees C growth. The structure of this complex is altered in that more sites become accessible to lactoperoxidase. This is particularly true of the 51 kdalton protein, which is barely labeled by wild-type PS II complexes.
...
PMID:Internal and external membrane proteins of the cyanobacterium, Synechococcus cedrorum. 678 86


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---