scholarly journals The identification of the heat-stable microsomal protein required for methoxyflurane metabolism as cytochrome b5.

1984 ◽  
Vol 259 (4) ◽  
pp. 2541-2546
Author(s):  
E Canova-Davis ◽  
L Waskell
Keyword(s):  
Cytochrome B5 ◽  
Microsomal Protein ◽  
Heat Stable

Hepatic function in rats after spaceflight: effects on lipids, glycogen, and enzymes

1987 ◽  
Vol 252 (2) ◽  
pp. R222-R226 ◽  
Author(s):  
A. H. Merrill ◽  
E. Wang ◽  
D. P. Jones ◽  
J. L. Hargrove
Keyword(s):  
Specific Activity ◽  
Cytochrome B5 ◽  
Hepatic Metabolism ◽  
Microsomal Protein ◽  
Hepatic Function ◽  
Tyrosine Aminotransferase ◽  
Fatty Acyl ◽  
Blood Cholesterol ◽  
Serine Palmitoyltransferase ◽  
Coa Reductase

The inclusion of rats aboard Spacelab 3 (SL-3) allowed analyses of liver lipids, glycogen, hepatic enzymes of cholesterol, glycerolipid and sphingolipid biosynthesis, and other enzyme activities. Glycogen content was markedly elevated in livers from the flight animals compared with controls. Cholesterol was 24% (P less than 0.04) lower in livers from the experimental groups, whereas blood cholesterol was 19% higher (P less than 0.05). The activity of 3-hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme of steroid biosynthesis, was 80% lower (P less than 0.01). Total phospholipids and sphingolipid levels did not differ significantly. The specific activity of fatty acyl-CoA synthetase, which is responsible for activation of fatty acids, was 37% (P less than 0.05) higher in microsomes from the rats on SL-3; however, since these animals had 25% less microsomal protein (P less than 0.02), there was no difference per gram of liver. The initial enzymes of sphingolipid and glycerolipid biosynthesis were assayed; serine palmitoyltransferase was 40% lower (P less than 0.01), and glycerol 3-phosphate acyltransferase did not differ. Hepatic cytochrome P-450 content decreased by 50% after spaceflight. Enzymes that did not differ significantly between the two groups include cytochrome b5, glutathione S-transferase, tyrosine aminotransferase, aspartate aminotransferase, and cystathionase. These findings suggest that spaceflight alters hepatic metabolism of several classes of compounds.

scholarly journals ANALYTICAL STUDY OF MICROSOMES AND ISOLATED SUBCELLULAR MEMBRANES FROM RAT LIVER

1974 ◽  
Vol 61 (1) ◽  
pp. 213-231 ◽  
Author(s):  
Henri Beaufay ◽  
Alain Amar-Costesec ◽  
Denise Thinès-Sempoux ◽  
Maurice Wibo ◽  
Mariette Robbi ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Cytochrome C ◽  
Monoamine Oxidase ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Cytochrome B5 ◽  
Microsomal Protein ◽  
Cytochrome C Reductase ◽  
Group A ◽  
Group B

Rat liver microsomal fractions have been equilibrated in various types of linear density gradients. 15 fractions were collected and assayed for 27 constituents. As a result of this analysis microsomal constituents have been classified, in the order of increasing median density, into four groups labeled a, b, c, and d. Group a includes: monoamine oxidase, galactosyltransferase, 5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase, and cholesterol; group b: NADH cytochrome c reductase, NADPH cytochrome c reductase, aminopyrine demethylase, cytochrome b5, and cytochrome P 450; group c: glucose 6-phosphatase, nucleoside diphosphatase, esterase, ß-glucuronidase, and glucuronyltransferase; group d: RNA, membrane-bound ribosomes, and some enzymes probably adsorbed on ribosomes: fumarase, aldolase, and glutamine synthetase. Analysis of the microsomal fraction by differential centrifugation in density gradient has further dissociated group a into constituents which sediment more slowly (monoamine oxidase and galactosyltransferase) than those of groups b and c, and 5'-nucleotidase, alkaline phosphodiesterase I, alkaline phosphatase, and the bulk of cholesterol which sediment more rapidly (group a2). The microsomal monoamine oxidase is attributed, at least partially, to detached fragments of external mitochondrial membrane. Galactosyltransferase belongs to the Golgi complex. Group a2 constituents are related to plasma membranes. Constituents of groups b and c and RNA belong to microsomal vesicles derived from the endoplasmic reticulum. These latter exhibit a noticeable biochemical heterogeneity and represent at the most 80% of microsomal protein, the rest being accounted for by particles bearing the constituents of groups a and some contaminating mitochondria, lysosomes, and peroxisomes. Attention is called to the operational meaning of microsomal subfractions and to their cytological complexity.

Solution structure of cytochrome b5 mutant (E44/48/56A/D60A) and its interaction with cytochrome c

2001 ◽  
Vol 268 (6) ◽  
pp. 1620-1630
Author(s):  
Yibing Wu ◽  
Yunhua Wang ◽  
Chengmin Qian ◽  
Jun Lu ◽  
Ercheng Li ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Solution Structure ◽  
Cytochrome B5

Heat stable toxin of E. coli (STa) stimulates duodenal mucosal bicarbonate secretion in cystic fibrosis knockout mice

2001 ◽  
Vol 120 (5) ◽  
pp. A137-A137
Author(s):  
D CHILDS ◽  
D CROMBIE ◽  
V PRATHA ◽  
Z SELLERS ◽  
D HOGAN ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Knockout Mice ◽  
Bicarbonate Secretion ◽  
E Coli ◽  
Heat Stable

Plasminogen Activator and Plasminogen Activator Inhibitor Associated with Granulomatous Inflammation: A Study with Murine Leprosy

1984 ◽  
Vol 52 (03) ◽  
pp. 243-249 ◽  
Author(s):  
S Izaki ◽  
T Hibino ◽  
Y Isozaki ◽  
P S Hsu ◽  
M Izaki ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Soluble Fraction ◽  
Proteinase Inhibitors ◽  
Granulomatous Inflammation ◽  
Serine Proteinase ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Weakly Alkaline ◽  
Heat Stable ◽  
Type Plasminogen Activator

SummaryPlasminogen activator that is associated with the development of hypersensitivity granulomas (gPA) was partially purified from a saline soluble fraction of murine lepromas elicited in “resistant” mice, C57BL/6N. The gPA was shown to consist of two subspecies (23,000 and 48,000 in molecular weight) with essentially identical enzymologic properties. The gPA was found to be a relatively heat stable weakly alkaline serine proteinase with trypsin-like characteristics in the specificity for synthetic substrates and proteinase inhibitors. It showed a high affinity for H- D-Ile-Pro-Arg-pNA (Km = 1.4 × 10-4 M) H-D-Val-Leu-Lys- pNA (Km = 5.2 × 10-4 M), and L-pyroGlu-Gly-Arg-pNA (Km = 9.3 × 10-4 M). The gPA did not demonstrate antigenic cross reaction with urokinase-type or tissue-type plasminogen activator.Two distinct enzymatic regulators of the gPA were also demonstrated in the saline soluble fraction of the hypersensitivity granulomas. The gPA and its regulation are assumed to be correlated with macrophage activation in the hypersensitivity granulomas

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