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

Coenzymes participate in many of the enzyme analyses performed in the clinical laboratory. Supplementation of assay systems with optimal levels of coenzymes has recently been recommended as part of efforts to achieve interlaboratory standardization of enzyme measurements. Aspartate aminotransferase and alanine aminotransferase require pyridoxal phosphate for expression of enzyme activity. The role of this coenzyme in enzymatic transamination and the effects of its supplementation on the clinical estimation of these two enzymes is reviewed. Other coenzymes discussed are flavins, coenzymes for glutathione reductase, glucose oxidase, cholesterol oxidase and diaphorase, as well as thiamine pyrophosphate, coenzyme for transketolase. Catalase and peroxidase are used as examples of hemoproteins utilized in clinical measurements. Two peptide coenzymes, colipase and glutathione, are also considered. Measurement of apoenzyme stimulation upon supplementation with specific coenzymes is discussed as a valuable technique for quantitative coenzyme measurements or assessment of vitamin nutritional status.
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PMID:Review: the role of coenzymes in clinical enzymology. 33 88

A fully enzymatic method to determine total cholesterol in serum is described. The method appears especially suitable for adaptation to discrete mechanical analyzers either of the single channel or the multi-channel type. The method uses the enzymes cholesterol esterase (EC 3.1.1.13), cholesterol oxidase (EC 1.1.3.6) and peroxidase (EC 1.11.1.7) with 4-aminophenazone and phenol as substrates in the indicator reaction. The method was adapted to the Greiner Selective Analyzer GSA-II. For this purpose the critical parameters of the reaction were intensively examined. The complete reagent is stable within the GSA II dispenser at 4 degrees C for at least 1 week. By omitting cholesterol oxidase in the blank reagent a sample bland and a partial reagent blank are obtained. Within a range up to 10.4 mmol/1 (4.0 g/l) the maximum colour is developed within 6 minutes. The calibration factor was stable for 4 months. The method allows absolute measurements. At concentrations between 2 and 4 mmol/1 within-batch precision ranged from 0.5 to 1.4%. Precision from day to day for the same control sera amounted to 2.8; 2.0; 2.7 and 2.0% for a period of 3 months. Examination of accuracy yielded satisfying results. Ascorbic acid in the physiological range did not alter results to a significant extent. Catalase or novaminesulfone added in vitro did not interfere. Optical interferences by bilirubin, hemoglobin or turbidity are compensated by a sample blank. A comparison of results with the enzymatic method of Roeschlau et al. (Z. Klin. Chem. Klin. Biochem. 12, 226 (1974)) yielded satisfactory agreement. The limits of detection of the present method can be lowered by a factor of 2.2 by replacing phenol by dihalogen phenols.
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PMID:[Enzymatic determination of total cholesterol with the Greiner Selective Analyzer (GSA-II) (author's transl)]. 87 Jun 10

Rhodococcus equi is a well-characterized bacterial pathogen which lyses cell membranes with the help of cholesterol oxidase (CO). Survival in macrophages is warranted by its ability to resist reactive radicals via catalase and superoxide dismutase (SOD). Therefore, CO production in the absence or presence of 0.1 % cholesterol and sensitivity to exogenous hydrogen peroxide (H2O2) and superoxide anion (SOA) were tested in seven strains of R. equi in vitro. When R. equi strains were grown on agar plates with cholesterol, the bacterial growth [colony-forming units (cfu)/plate] did not increase significantly in comparison with the growth on plates without cholesterol. The activity of CO increased, significantly for extracellular CO. In subsequent experiments, R. equi strains grown on cholesterol were stressed with H2O2 or SOA so that approximately 10 % of cfu/plate survived. During stress induced by SOA, membrane CO and SOD activity increased significantly. Catalase activity increased 2-fold with H2O2 and 3-fold with SOA exposure. These data suggest that the presence of cholesterol induces CO in bacteria grown on agar plates. Catalase, SOD and even membrane-bound CO respond to reactive oxygen species.
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PMID:Cholesterol oxidase and resistance of Rhodococcus equi to peroxidative stress in vitro in the presence of cholesterol. 1224 Oct 35