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)

The study dealt with the formation of dityrosine - a cross-link in some proteins including collagen - by human salivary lactoperoxidase. Dityrosine formation was found at pH range 6.6 to 9.3 with maximum reaction velocity at pH 8.5. However, thiocyanate ions at physiological salivary concentrations inhibited dityrosine formation by 70 to 80 per cent compared with the optimum rate. The inhibition seemed to result from the competition of SCN ions and L-tyrosine for the same binding site on enzyme surface. The possibility of dityrosine cross-linking in vivo in human oral fluid seems to be limited compared with e.g. human milk or macaque saliva where the concentration of SCN ions is low but the activity of lactoperoxidase is considerably high.
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PMID:Formation of dityrosine by human salivary lactoperoxidase in vitro. 3 19

Horseradish peroxidase (HRPO) conjugated with goat antihuman IgG, goat antihuman IgM, and aggregated human IgG has been used as a enzymatic marker to stain IgG, IgM, and rheumatoid factor in rheumatoid cartilage. When Hrpo-anti IgG and HRPO-anti IgM were used, immunoglobulin deposits were not observed in nonrheumatoid cartilage. However 7 of 8 rheumatoid cartilage specimens stained with HRPO-anti IgG showed electron-dense deposits. Three rheumatoid specimens stained with HRPO-anti IgM showed similar findings. Both of 2 rheumatoid specimens also stained positively with HRPO conjugated with aggregated IgG, a finding indicating that rheumatoid factor was present. The deposits were seen between the collagen fibers of the superficial layer of the cartilage to a maximal depth of 22 mu from the surface (average: 7 mu). The amorphous fibrinous material on the surface of the cartilage was also stained. The demonstration of IgG, IgM, and rheumatoid factor in the superficial zone of rheumatoid cartilage suggests that immune complexes are deposited in the cartilage in this disease.
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PMID:Electron microscopic demonstration of immunoglobulin deposition in rheumatoid cartilage. 5 68

Ultrastructural localization of C3 deposition in the skin of two patients with herpes gestationis was determined by using a peroxidase-antiperoxidase multistep technique. The tissue preparations can be stored for long periods of time and identical sections may be used for light and electron microscopic examination. The reaction products were seen throughout the entire lamina lucida and the basal cell plasma membrane appeared to be accentuated. The most remarkable ultrastructural changes in normal-appearing skin were the destruction of the basal cell membranes on the dermal side, localized cytoplasmic dissolution, and intracellular edema unaccompanied by inflammatory cells. Early, nonvesicular lesions showed basal cell degeneration and dermal inflammatory cells. Necrosis and loss of basal cells occurred in the next stage which resulted in microvesicles in which collagen or a well-preserved basal lamina formed the vesicle base. In the later blister stage, the basal lamina was usually lost. It is suggested that damage of basal cell membranes on their dermal side leads to the destruction of basal cells with the subsequent protrusion of epidermal and junctional substances into the dermis. This may result in inflammatory cell infiltration and blister formation.
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PMID:Herpes gestationis. Ultrastructure and ultrastructural localization of in vivo-bound complement. 5 51

Frozen sections of the growing end of the rat incisor tooth were exposed to antisera or affinity prepared antibodies against partially purified type I, II, or IV procollagen in the hope of detecting the location of the corresponding antigens by the peroxidase-anti-peroxidase technique. The distribution of immunostaining was similar with antisera as with purified antibodies of a given type, but differed for each type; that is, predentin, odontoblasts, pulp and periodontal tissue were the sites of type I; blood vessel walls, pulp and periodontal tissue, of type III; and basement membranes, of type IV antigenicity. It was demonstrated, at least in cases of type I and III, that immunostaining detected the corresponding procollagens and related substances, but not the corresponding collagens. The interpretation of these observations is that: 1) odontoblasts elaborate procollagen I for release to predentin and subsequent transformation to dentinal collagen I; 2) pulp and periodontal cells produce procollagens I and III which presumably become collagens I and III respectively, while the adventitial cells of blood vessels give rise to collagen III; and 3) procollagen IV is associated with basement membranes and, occasionally, adjacent cells.
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PMID:Immunohistochemical localization of procollagens. I. Light microscopic distribution of procollagen I, III and IV antigenicity in the rat incisor tooth by the indirect peroxidase-anti-peroxidase method. 8 53

In an attempt to locate procollagen I in rats odontoblasts, antibodies raised in rabbits were purified by affinity methods and linked to peroxidase. They were then incubated with chopped slices from the growing end of rat incisor teeth. The antibodies binding to the antigens in the slices were visualized by reacting the peroxidase moiety with diaminobenzidine in the presence of hydrogen peroxide. The slices were then embedded in Epon and sectioned for ultrastructural study. Within odontoblasts, the immunostaining indicative of procollagen I antigenicity is moderate in rough endoplasmic reticulum cisternae, strong in spherical and cylindrical Golgi distensions, intense in secretory granules, and variable in lysosomal structures. In predentin, immunostaining is intense close to the odontoblast layer, but decreases gradually in a distal direction. Hence, procollagen I (and/or substances endowed with similar antigenicity such as pro alpha (I) chains and procollagen fragments) is present: 1) along the intracellular pathway of collagen precursors where its concentration gradually increases to reach a maximum in secretory granules; 2) in predentin, into which it is released from the granules for transformation into nonimmunoreactive collagen I; and 3) in lysosomal structures where some of it is hydrolyzed.
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PMID:Immunohistochemical localization of procollagens. II. Electron microscopic distribution of procollagen I antigenicity in the odontoblasts and predentin of rat incisor teeth by a direct method using peroxidase linked antibodies. 8 54

The ultrastructural study of non-decalcified periodontal ligament of rats, labeled with horseradish peroxidase used as an enzymatic tracer for the mechanism of endocytosis, shows that there exists in the fibroblast, on the one hand, an endogeneous peroxidase revealed by the preparation and characteristic of certain cellular organelles: mitochondria, free ribosomes, ribosomes of the granular endoplasmic reticulum; and on the other hand an exogeneous peroxidase which demonstrates the ability of fibroblasts to phagocytose. This exogeneous peroxidase initially marks the collagen fibrils located in the extracellular medium, then at a later time he cytoplasmic membrane during its invagination, and finally the membrane of phagosomes. The intracellular collagen situated at the interior of phagosomes is also marked by the peroxidase and demonstrates the passage of the collagen from the extracellular medium to the intracellular medium.
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PMID:[Ultrastructural demonstration of the phagocytic activity of periodontal ligament fibroblasts in the rat using enzymatic tracers]. 12 4

1. An investigation on the structure and chemical nature of the cuticle of a nematomorph worm Gordius robustus and its role in the physiology of the endoparasitic phase has been conducted. 2. The cuticle has fundamentally three layers; the cortical, homogeneous and fibrillar layers, differing from one another in physical as well as chemical properties. 3. The cortical layer has organic sulphur and acid mucopolysaccharide; the homogeneous layer has organic sulphur together with collagen-like protein and the fibrillar layer has only collagen. 4. Electrophoretic and chromatographic analyses reveal the presence of four proteins with different amino acid composition; the carbohydrate components of the cuticle are galactose and mannose. 5. Alkaline phosphatase and non-specific esterase are found in the cuticle of the general body surface and these seem to be related to the cutaneous absorption of materials. 6. Using peroxidase as tracer protein, the absorption of materials across the cuticle from outside the body has been demonstrated; this absorption is found to be an active process.
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PMID:A study of the cuticle of Gordius robustus, a nematomorph worm. I. Cuticle in the parasitic phase. 13 51

A study documenting the localization in human arteries of apoproteins from human plasma high density (HDL, low density (LDL), and very low density (VLDL) lipoproteins was undertaken in light of their possible roles in the pathogenesis and regression of the atherosclerotic process in man. Apo A-I from HDL, apo B from LDL, apo C-III from VLDL were all localized by immunohistochemical techniques to generally the same areas of athersclerotic lesions. These consisted of certain bands of collagen and elastic fibers in fatty streaks and fibrous plaques, and extracellular pools of neutral lipid in fibrous plaques. Apoproteins were also occasionally present in areas of diffuse intimal thickening in coronary arteries. Extensiveness and frequency of appearance of apo B in atherosclerotic lesions was greatest in type II hyperlipoproteinemics, thus correlating with the plasma apo B levels. Employing an immuno-peroxidase procedure, apo B was localized ultrastructurally in atherosclerotic lesions to the outer surface of spheres ranging in diameter between 250 and 700 A. These spheres, localized predominantly in lipid cores and between collagen bands, were also seen in negatively-stained preparations of arterial extracts which also reacted positively against anti-apo B, SUGGESTING THAT THE SPHERES MAY REPRESENT NATIVE LDL and VLDL. The superimposed localization of apo A-I, apo B, and apo C-III in atherosclerotic lesions suggests that a specific interaction exists between certain lesion components and these apoproteins.
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PMID:Apo-lipoprotein localization in human atherosclerotic arteries. 17 92

Bone destruction, commonly associated with chronic otitis media, requires collagen degradation. Collagenase, a neutral protease, appears to be an essential component in the process of collagen breakdown. Collagenase was identified within chronically inflamed and normal guinea pig temporal bones using an immunohistochemical technique with fluorescein isothyocyanate and peroxidase-antiperoxidase labels. Localization of the enzyme identifies sites of matrix resorption. Collagenase was found in osteoclasts, osteocytes, mononuclear inflammatory cells, and at resorbing margins. Inflammation increased the intracellular collagenase content of inflammatory bone osteocytes when compared to normal osteocytes using a microspectrofluorometer. It appears that the inflammatory process directly influences bone destruction through the action of mononuclear inflammatory cells and indirectly by stimulating bone cells to increase their proteolytic enzyme production.
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PMID:Localization of collagenase in chronically inflamed guinea pig temporal bone. 22 7

A general consideration of the pathogenesis of the various metabolic diseases which produce mental deficiency suggests that perturbation of the one carbon (folate) cycle may be important. Secondly, a review of diseases having some symptoms in common with trisomy 21 suggests the evidence of : a collagen disturbance (hypothyroidism and iminodipeptidurial) ; an oxygen disturbance (hypothyroidism and hemoglobinopathies) ; a cholinergic distrubance (Alzheimer's disease) ; a one-carbon-cycle disturbance (Lesch-Nyhan's disease). Thirdly, the peculiar pathology of trisomy 21 allows to find also a cholinergic disturbance and a disturbance close to the 10 formyl-tetrahydrololate entry of the folate cycle. Finally, an analysis of the possible effect of the excess of superoxide dismutase A and of the increase of glutathion peroxidase leads to the suspicion that a difficulty exists of dioxygenations and of non aromatic hydroxilations with a relative retardation of some FAD requiring reactions. A simplified scheme shows that these metabolic deviations could provoke a disturbance of the collagen and of synthesis of chemical mediators, in accordance with the indications furnished by the compared pathogenesis of the various affections studied. These heuristic reflexions open the way to further investigations.
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PMID:[Biochemical investigations and trisomy 21 (author's transl)]. 22 17


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