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:3.4.21.1 (chymotrypsin)
10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Methoxypolyethylene glycols of 1900 daltons (PEG-1900) or 5000 daltons (PEG-5000) were covalently attached to bovine liver catalase using 2,4,6-trichloro-s-triazine as the coupling agent. Rabbits were immunized by the intravenous and intramuscular routes with catalase modified by covalent attachment of PEG-1900 to 43% of the amino groups (PEG-1900-catalase). The intravenous antiserum did not yield detectable antibodies against PEG-1900-catalase or native catalase, as determined by Ouchterlony and complement fixation methods, whereas the intramuscular antiserum contained antibodies to both PEG-1900-catalase and catalase. PEG-1900 did not react with either antiserum. Catalase was prepared in which PEG-5000 was attached to 40% of the amino groups (PEG-5000-catalase). This catalase preparation did not react with either antiserum. PEG-1900-catalase retained 93% of its enzymatic activity; PEG-5000-catalase retained 95%. PEG-5000-catalase resisted digestion by trypsin, chymotrypsin, and a protease from Streptomyces griseus. PEG-1900-catalase and PEG-5000-catalase exhibited enhanced circulating lives in the blood of acatalasemic mice during repetitive intravenous injections. No evidence was seen of an immune response to injections of the modified enzymes. Mice injected repetitively with PEG-5000-catalase remained immune competent for unmodieied catalase, and no evidence of tissue or organ damage was seen.
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PMID:Effect of covalent attachment of polyethylene glycol on immunogenicity and circulating life of bovine liver catalase. 1 7

Twelve antigens were detected in crude group C streptococcal extracellular concentrates, using naturally occurring antibodies in normal human gamma globulin. These group C streptococcal antigens all appeared to be present in crude group A streptococcal extracellular concentrates, although the latter contained additional antigens reactive with the human antibodies. Systematic purification procedures were established for the isolation of the group C streptococcal antigens by a sequence of salting out, hydroxylapatite chromatography, Sephadex G-100 gel filtration, and isoelectric focusing. With such procedures, three of the group C streptococcal antigens were isolated in a relatively pure state. One of the purified antigens was identified as streptokinase on the basis of its fibrinolytic potency, its reaction of identity with two purified streptokinase fractions obtained from other sources, and its high titer in immunodiffusion assays. The most highly purified streptokinase fractions, derived from the 0.1 M sodium phosphate hydroxylapatite eluate, revealed a plasmin-inhibiting effect at high concentrations of streptokinase. This was not seen in the purified streptokinase of equivalent functional and immunological purity that was derived from the 0.2 M sodium phosphate hydroxylapatite peak. Two other streptococcal antigens were also isolated to a high degree during the course of the above study. These were designated antigens X and Y and were found to be unrelated immunologically to each other or to streptokinase. Their isoelectric points were 6.7 and 8.8, respectively, and both were present in group A streptococcal concentrates. Esterase activity was found to be widely distributed in almost all of the fractions obtained in the various purification steps, indicating a high degree of heterogeneity of the streptococcal enzyme. Histochemical staining techniques applied to the immune precipitates formed with human antibodies indicated that none of the antigens detected in crude group C and group A streptococcal concentrates possessed catalase, glucuronidase, glucosaminidase, acid or alkaline phosphatase, arylsulfatase, leucineaminopeptidase, or chymotrypsin enzymatic activities.
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PMID:Purification of group C streptococcal extracellular antigens detected with naturally occurring human antibodies: isolation of streptokinase and two previously undescribed antigens. 13 Nov 8

Mechanisms were studied that might explain the attachment and damage to Candida albicans pseudohyphae by neutrophils in the absence of serum. Attachment of neutrophils to pseudo hyphae was inhibited by Candida mannans (1-10 mg/ml), but not by mannose, dextran, chitin, conconavalin A, or highly charged polyamino acids. Contact was also inhibited by pretreatment of Candida before incubation with neutrophils with chymotrypsin, but not trypsin or several inhibitors of proteases. Similar results were obtained with pretreatment of neutrophils, except that trypsin was inhibitory. When pseudohyphae were killed with ultraviolet light, proteinpolysaccharide complexes of mol wt <10,000 were released which appeared to bind to the surfaces of neutrophils and inhibit contact between neutrophils and Candida, as well as other fungi. Damage to Candida by neutrophils was inhibited by agents known to act on neutrophil oxidative microbicidal mechanisms, including sodium cyanide, sodium azide, catalase, superoxide dismutase, and 1, 4 diazobicyclo (2, 2, 2) octane, a singlet oxygen quencher. Neutrophils from a patient with chronic granulomatous disease did not damage Candida at all. However, the hydroxyl radical scavengers mannitol and benzoate were not inhibitory. Cationic proteins and lactoferrin also did not appear to play a major role in this system. Low concentrations of lysozyme which did not damage Candida in isotonic buffer solutions damaged pseudohyphae in distilled water. Isolated neutrophil granules damaged pseudohyphae only with added hydrogen peroxide and halide, and damage occurred only with granule fractions known to contain myeloperoxidase. These findings suggest that neutrophils recognized a molecule on the Candida surface which has a chymotrypsin sensitive protein component, and which may be liberated from the cell surface upon death of organism. The neutrophil receptors for Candida appear to be sensitive to trypsin and chymotrypsin. Damage to Candida by neutrophils occurred primarily by oxidative mechanisms, including the production of superoxide and hydrogen peroxide interacting with myeloperoxidase and halide, as well as singlet oxygen, but did not appear to involve hydroxyl radical. Lysozyme might have an accessory role, under some conditions.
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PMID:Mechanisms of attachment of neutrophils to Candida albicans pseudohyphae in the absence of serum, and of subsequent damage to pseudohyphae by microbicidal processes of neutrophils in vitro. 34 Apr 71

Carrageenan or thrombin-induced aggregation of plasma-free rabbit platelets was inhibited by calcium and magnesium chelating agents, by N-ethylmaleimide and by drugs that increase the intra-cellular cyclic AMP content. Inhibitors of prostaglandin (PG) synthetase were only partially active, and had to be present in the platelet suspension to inhibit aggregation. Inhibition of PG synthetase, as evaluated by bioassay and by AA-induced platelet aggregation, was not reduced when inhibitors were washed from platelets. The phospholipase A2 inhibitors bromophenacyl bromide and mepacrine, the chymotrypsin inhibitor tosylphenylalaninechloromethylketone, catalase and dithiothreitol also inhibited aggregation, whereas inhibitors of trypsin failed to do so. Incubation of rabbit platelet-rich plasma with carrageenan was followed by generation of PG-like and of rabbit aorta contracting activities. Generation of these activities was inhibited by drugs effective against aggregation, and also by non-steroidal anti-inflammatory drugs. Aggregation of rabbit platelets by carrageenan and by thrombin does not appear to be dependent upon activation of PG synthetase, although PG-like substances are formed during aggregation.
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PMID:Involvement of mediators in the interaction of platelets and carrageenan. 41 34

Pyrolysis gas chromatography (PGC) has been shown to be useful for differentiating enzymes. The enzymes alpha-chymotrypsin, lactate dehydrogenase, catalase, and urease were easily "fingerprinted" on a 1.8 m 0.5% Carbowax 20 M column. Also, in some cases, isoenzymes of lactate dehydrogenase could be distinguished. Based on the pyrolyses of the free aromatic amino acids, four major enzyme pyrolysis peaks were tentatively identified as organic compounds derived from tyrosine and tryptophan. The use of a nitrogen-selective detector in conjunction with the FID and measurement of peak retention times by computer on three different types of columns permitted confirmations of peak identity.
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PMID:Pyrolysis gas chromatography of enzymes. 73 Aug 12

A new species, Porphyromonas circumdentaria, is proposed for pigmented, asaccharolytic strains that were isolated from the gingival margins or mouth-associated diseases of cats. This bacterium is an obligately anaerobic, gram-negative, brown- or black-pigmented, asaccharolytic, nonmotile, nonsporing, rod-shaped organism which does not grow in bile and has a guanine-plus-cytosine content of 40 to 42 mol%. It produces major amounts of acetic, butyric, and isovaleric acids and minor amounts of propionic, isobutyric, and phenylacetic acids as end products of metabolism in cooked meat medium. Glutamate and malate dehydrogenases are present, while 6-phosphogluconate and glucose-6-phosphate dehydrogenases are absent. The major cellular fatty acid is 13-methyltetradecanoic acid (iso-C15:0 acid). P. circumdentaria strains are catalase positive and produce ammonia, and colonies fluoresce under short-wavelength UV light. These strains do not hemagglutinate erythrocytes, exhibit trypsinlike activity, or produce chymotrypsin or alpha-fucosidase. They are heavily piliated and produce a capsule. The type strain is strain VPB 3329 (= NCTC 12469). Bacteroides salivosus (D. N. Love, J. L. Johnson, R. F. Jones, and A. Calverley, Int. J. Syst. Bacteriol. 37:307-309, 1987) is an obligately anaerobic, gram-negative, pigmented, asaccharolytic, nonmotile, rod-shaped organism which does not grow in bile and has a guanine-plus-cytosine content of 42 to 44 mol%. This organism produces major amounts of acetic, butyric, and phenylacetic acids and minor amounts of isobutyric and isovaleric acids as end products of metabolism in cooked meat medium.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Description of Porphyromonas circumdentaria sp. nov. and reassignment of Bacteroides salivosus (Love, Johnson, Jones, and Calverley 1987) as Porphyromonas (Shah and Collins 1988) salivosa comb. nov. 150 73

With an isolated, blood-perfused canine lung-lobe preparation, the potential role of reactive oxygen metabolites and neutrophils in pancreatic protease (alpha-chymotrypsin)-induced acute lung injury was studied. Administration of alpha-chymotrypsin caused a low-pressure pulmonary edema (mean lung lobe weight increased from 71 to 197 gm). Pretreatment with superoxide dismutase alone did not attenuate the injury (58 to 166 gm), but when combined with catalase, the injury was significantly ameliorated (64 to 107 gm). However, depletion of circulating leukocytes did not attenuate the injury (69 to 200 gm). These findings suggest that circulatory proteases can cause lung injury by a mechanism that is mediated, at least in part, by toxic oxygen metabolites that are not of neutrophil origin.
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PMID:Lung injury produced by pancreatic proteases in dogs. 162 Dec 27

The ornithine decarboxylase-inducing factor (ODC factor) was purified about 1,000-fold in 42% yield from the ascites fluids of an Ehrlich ascites tumor by a combination of centrifugation and concanavalin A (ConA) treatment. A single ip injection of 0.5 micrograms of the purified factor per mouse resulted in half-maximum induction of liver ODC. The factor was found to be a trypsin- and chymotrypsin-resistant, acidic glycoprotein (pI about 4.43) with a minimum molecular weight of about 70 kilodaltons, containing a disulfide bond(s) in its functional domain. It did not react with ConA. This factor induced retrodifferentiation of liver function, causing a marked increase of prototype M2 isozyme of pyruvate kinase. It reduced liver catalase activity, and also modified thyroid hormone metabolism, reducing the serum levels of T4 and T3. These results suggest that the ODC factor is multifunctional and induces many of the changes observed in a tumor-bearing host.
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PMID:Purification of ornithine decarboxylase-inducing factor from cell-free ascites fluid of Ehrlich ascites tumor and its characteristics. 170 56

1. Methacholine relaxed phenylephrine-contracted aorta of the rat with the endothelium intact. This effect was inhibited by haemoglobin, methylene blue, gossypol, phenidone and L-NG-nitroarginine methyl ester (L-NAME). Rat aorta denuded of endothelium failed to relax in response to methacholine, histamine and the peptidoleukotrienes C4, D4 and E4. 2. Methacholine and histamine but not leukotrienes C4, D4 and E4 relaxed phenylephrine-contracted rat aorta without endothelium when surrounded by rabbit epithelium-intact bronchus. The muscarinic antagonist atropine antagonized the methacholine-induced relaxation. 3. Removal of the epithelium either mechanically or chemically, abolished methacholine-induced relaxation of rat aorta in the co-axial bioassay. These data indicate that the epithelium is responsible for the observed relaxant effect to methacholine and histamine. 4. The cyclo-oxygenase inhibitor, indomethacin, the phospholipase A2 inhibitor, mepacrine and the lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA), failed to inhibit methacholine-induced relaxation of rat aorta in the co-axial bioassay. This indicates that the epithelium-derived inhibitory factor (EpDIF) is not a product of the cyclo-oxygenase or lipoxygenase pathway or a product derived from activation of phospholipase A2. 5. Haemoglobin, methylene blue, phenidone, gossypol and L-NAME failed to inhibit the relaxation of rat aorta in the co-axial bioassay. These results demonstrate that EpDIF detected in the co-axial bioassay is not endothelium-derived relaxing factor (EDRF) or nitric oxide. Similarly, catalase was without effect. 6. EpDIF is unlikely to be a peptide since papain and alpha-chymotrypsin failed to alter the methacholine-induced relaxation of rat aorta in the co-axial bioassay. Furthermore, thiorphan, captopril and aprotinin were also without effect, suggesting that EpDIF is not a substrate for airway peptidases. 7. The results presented in this paper demonstrate the release of a vasoactive epithelium-derived inhibitory factor (EpDIF) from rabbit intrapulmonary bronchi by use of a co-axial bioassay preparation.
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PMID:The release of a non-prostanoid inhibitory factor from rabbit bronchus detected by co-axial bioassay. 185 18

We have used 125I-labeled fibronectin (FN) as an extracellular substrate for neutrophils (PMN) in order to investigate the mechanism responsible for FN solubilization by PMN and the effects of recombinant cytokines on this process. Pure active alpha 1-antitrypsin (alpha 1AT), when added to PMN before or during, but not after, adherence to FN, inhibited solubilization of the substrate in a dose-dependent manner, but alpha 1AT that had been inactivated by proteolysis or oxidation and alpha 1AT Pittsburgh (alpha 1AT 358Met-Arg) had no significant effect. The solubilization of FN was also inhibited by the PMN elastase inhibitor N-methoxysuccinyl-alanyl-alanyl-prolyl-valine-chloromethylketone but not by the chymotrypsin and cathepsin G inhibitor N-Cbz-glycyl-glycyl-phenylalanine-chloromethylketone, nor by catalase or superoxide dismutase. The products of solubilization of FN by PMN, analyzed by sodium dodecyl sulphate polyacrylamide electrophoresis, were similar to those produced by pure PMN elastase but not cathepsin G. These results suggest that FN solubilization by PMN is caused largely by the pericellular activity of PMN elastase. The solubilization of FN by PMN was increased significantly by adding tumor necrosis factor-alpha, interleukin-1 alpha, or interferon-gamma to the adherent cells but without a significant general release of elastase into the culture supernatants. Granulocyte/macrophage colony-stimulating factor (GM-CSF) had no significant effect. None of the cytokines had any effect when preincubated with the cells in suspension, and non increased FN solubilization by PMN incubated with the optimal (10(-6) mol/liter) or suboptimal dose (10(-8) mol/liter) of the peptide formylmethionylleucylphenylalanine.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Extracellular proteolysis of fibronectin by neutrophils: characterization and the effects of recombinant cytokines. 201 99


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