Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Illumination of oxidized cytochrome oxidase with low intensity (<2 mW) light below 300 nm in the presence of oxygen causes pH-dependent spectral changes in the Soret and visible regions. The light-induced difference spectra show a peak at 438 nm and a trough at 414 nm in the Soret region and a peak at 606 nm and a shoulder at approximately 577 nm in the visible region. The effect was inhibited by cyanide, suggesting the involvement of cytochrome a3. The pH dependence indicates two titratable groups with pKa values of 6.52 +/- 0.26 and 6.85 +/- 0.15. The spectral changes are analogous to those occurring upon addition of hydrogen peroxide to the fully oxidized enzyme, which results in a mixture of species with absorbance maxima at 607 and 580 nm when referenced against the oxidized enzyme. Catalase addition affected the initial onset of the spectral change and increased the rate at which the reverse reaction occurred upon termination of illumination. The data are consistent with a mechanism involving light-induced autoreduction of the binuclear center and subsequent O2 binding, followed by the release of hydrogen peroxide and the formation of a mixture of the 607 nm and 580 nm forms.
 ...
PMID:Light-induced spectral changes in fully oxidized cytochrome c oxidase in the presence of oxygen. 917 48

Mitochondrial fractions isolated from pears (Pyrus communis L.) at the climacteric minimum and peak were subjected to sucrose density gradient centrifugation. The distribution of protein and specific activities of 3 enzymes from this mitochondrial fraction were investigated.Cytochrome oxidase specific activity remained associated with the particulate fraction and increased slightly during the period in which respiration of the whole fruit reached its climacteric peak. Catalase and acid phosphatase specific activity was associated with both the particulate and the least dense region of the gradient and decreased with postharvest ripening.Evidence for several differences between the subcellular behavior of catalase and acid phosphatase from pear tissue compared to their counterparts isolated from mammalian cells is discussed. A general shift of maximum specific enzymic activities and protein distribution to lighter regions of the density gradient occurs with ripening, suggestive of diminution in size or density of intracellular particles.
 ...
PMID:Sucrose density gradient distribution of mitochondrial protein and enzymes from preclimacteric and climacteric pears. 1665 69

1. Eight distinct acid-hydrolase activities present in cytoplasmic extracts from bone tissue occur in latent form to the extent of 50-70% of their total activity, depending on the enzyme. 2. This latency can be decreased or suppressed by exposure to Triton X-100 or to media of low osmotic pressure, by treatment in the Waring Blendor, and by freezing and thawing, but not by increasing the substrate concentration in the assay medium up to 10-fold the Michaelis constant of the enzymes. 3. Latency is the property of the particle-bound enzymes, and treatments that suppress latency simultaneously cause solubilization of the enzymes. Most enzymes show an excess of free over soluble activity; the magnitude of this excess seems to depend largely on the nature of the enzyme, and sometimes also on the kind of treatment suffered by the preparations; it is attributed mainly to adsorption artifacts. 4. In preparations subjected to graded activating treatments, seven of the eight acid hydrolases studied are released in closely parallel fashion, suggesting that they are associated with particles possessing similar properties. Acid phenylphosphatase is released less readily than the other enzymes by Triton X-100 and by exposure to media of low osmotic pressure. 5. It is concluded from these and previous published fractionation experiments that, with the possible exception of part of the acid-phenylphosphatase activity, the eight acid hydrolases studied belong to lysosome-like particles. Bone lysosomes exhibit a relatively high degree of biochemical and physical heterogeneity. Their possible functions are discussed. Part of the acid-phenylphosphatase activity could be linked to another group of particles. 6. Catalase is also partly (30%) latent in cytoplasmic extracts of bone. Latent catalase can be released by some of the treatments that suppress the latency of the lysosomal enzymes, but differs from the latter by a greater resistance to Triton X-100, and, especially, by a complete insensitivity to exposure to media of low osmotic pressure. It is concluded from these results that the catalase-containing particles are probably different from lysosomes, as they are in liver. 7. Cytochrome oxidase, which is presumably associated with the mitochondria, and alkaline phenylphosphatase, an enzyme occurring predominantly in the microsomal fraction, exhibited no latency under the conditions of the present experiments.
 ...
PMID:Studies on bone enzymes. The activation and release of latent acid hydrolases and catalase in bone-tissue homogenates. 1674 44

The results of this study of the effect of temperature on the respiratory mechanism of five stenothermophilic bacteria may be summarized as follows:- 1. The respiratory mechanism and its various components of the stenothermophilic bacteria were found to function at temperatures below the minimum temperature for growth of these organisms. In every case the rates of the individual reactions involved in the respiratory chain increased exponentially with temperature until the temperature at which inactivation became apparent was reached. 2. The mean activation energies, calculated from the "best" value for the slope of the straight lines resulting from a plot of log rate against the reciprocal of the absolute temperature were: Dehydrogenases: 28,000 to 28,500 calories per gram molecule. Glucose, fructose, galactose, mannose, xylose, arabinose, maltose, lactose, sucrose, glycine, beta-alanine, monosodium glutamate, (asparagine). 19,500 to 20,500 calories per gram molecule. Ethyl alcohol, succinate, pyruvate, lactate, acetate. 19,500 to 20,500 calories per gram molecule. Ethyl alcohol, succinate, pyruvate, lactate, acetate. 15,000 calories per gram molecule. Formate. Cytochrome oxidase and cytochrome b and c (substrate: p-phenylenediamine): 16,800 calories per gram molecule. Cytochrome oxidase and cytochrome c (substrate: hydroquinone): 20,200 calories per gram molecule. Catalase: 4,100 calories per gram molecule. Complete aerobic respiratory system (plus added glucose): 29,500 calories per gram molecule. 3. The identity of the energies of activation of the respiratory system and its enzymic components at temperatures above and below the minimum temperature for growth of the stenothermophilic bacteria was demonstrated. 4. An attempt has been made to indicate a relationship between the nature of the substrate and the activation energy by grouping substrates on the basis of common micro values obtained for their dehydrogenation by resting cell preparations of stenothermophilic bacteria. The dehydrogenation reactions have been found to be the rate-controlling reactions in the aerobic respiratory system of these bacteria.
 ...
PMID:Temperature activation of certain respiratory enzymes of stenothermophilic bacteria. 1810 98

Suppression Subtractive Hybridization was employed in order to identify the differentially expressed genes in the hepatopancreas of white spot syndrome virus infected Fenneropenaeus indicus. A forward subtracted cDNA library generated 356 clones following a white spot syndrome virus infection. A total of 345 clones with more than 100 nucleotides were selected for further analysis using bioinformatics tools after vector screening. Twenty-three contigs and 111 singletons were generated from a total of 134 consensuses. The consensuses, on a sequence homology search using BLASTX (NCBI), revealed that 74 (55%) of them had no significant match to reported sequences in the database, suggesting that they were found for the first time and are probably associated with shrimp immune function. Out of the remaining 60 (45%) consensuses, 43 had significant homology to known protein sequences in the database while 17 consensuses are homologous to unknown proteins in the database which are considered novel. The most abundant genes in the subtracted library were antimicrobial peptides accounting for 56 clones; among which one is a member of SNF2 family of proteins and another belonged to PfP1 family of proteins on analysis using Antimicrobial peptide predictor software. The other predicted genes in the subtracted library include signal transduction molecules (GTPase, Serine threonine kinase, Armadillo repeats etc), antioxidant enzymes (Cytochrome oxidase, Monomeric sarcosine oxidase and Catalase), active transporters (Nuclear Localization Signal [NLS], calcium ATPase, sodium glutamate symporter, Store-Operated Calcium Entry [SOCE] and ribonucleoprotein [RNP]) contributing to 19, 14 and 5 clones respectively. Three clones are homologous to reverse transcriptase; a first time report in shrimp and one each belong to cell adhesion molecule and Proteinase. InterProScan at EMBL, when used for an integrated search at PROSITE predicted; signal sequences and transmembrane regions for 13 clones. This is the first report on the differential gene expression in WSSV-infected F. indicus. The high expression of immune related genes in response to virus infection in shrimp will provide a new insight into the crustacean innate immunity. Further work on the functionality of the unknown genes in shrimps will give an overview on the role of the differentially expressed genes during viral infection and increase our understanding for developing antiviral measures by making use of the shrimp defense mechanism.
 ...
PMID:Differential gene expression profile of the hepatopancreas of white spot syndrome virus infected Fenneropenaeus indicus by suppression subtractive hybridization. 2068 72