Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. We performed an enzymatic characterization of two different fractionation procedures of ventricles from rat hearts. The enzymatic assays covered succinic dehydrogenase as a marker for inner mitochondrial membranes, monoamine oxidase as a marker for outer mitochondrial membranes, NADPH-cytochrome c reductase and RNA as endoplasmatic reticular markers, acid phosphatase as a lysosomal marker, and lactic dehydrogenase as a marker for the "soluble" compartment; DNA was estimated for nuclear contamination. 2. The plasma membrane markers 5'-nucleotidase, Ca2+-ATPase, Mg2+-ATPase, Na+-K+-ATPase, and adenylate cyclase were determined. 3. The roughly prepared membrane fractions showed increased yields of the membrane markers; the number of beta receptors, determined with (-)-[3H] dihydroalprenolol and DL-propranolol, amounted to 68 +/- 6 fmol/mg protein (KD = 3390 +/- 450 pmol, Hill coefficient = 1.5). 4. The membrane fraction prepared with a linear sucrose gradient showed an increased inner mitochondrial membrane marker; presumably the outer mitochondrial membrane was stripped off. The beta-receptor number was 39 +/- 3 fmol/mg protein (KD = 6250 +/- 300 pmol; Hill coefficient = 1.2).
Cell Mol Neurobiol 1988 Jun
PMID:Beta-adrenergic receptors and enzymes in rat myocardial membranes: implications of fractionation procedures and beta-adrenoceptor antagonists. 284 52

In a previous report, mitochondria were proposed as a subcellular structure where recognition sites for peripheral benzodiazepine ligands are located in adrenal glands. The present study examines the subcellular distribution of specific binding sites for PK 11195 in eight tissues and compares the relative densities of these binding sites in mitochondrial-enriched fractions with the relative activities of two mitochondrial marker enzymes. In all eight tissues examined, PK 11195 binding sites were found to subfractionate in a manner nearly identical to that of the mitochondrial enzyme succinate dehydrogenase. The subcellular distribution patterns of specific PK 11195 binding sites were unrelated to the distribution patterns of marker enzymes for plasma membranes, lysosomes, or endoplasmic reticulum. Scatchard analyses of mitochondrial fractions from all eight tissues demonstrated a greater than 100-fold difference in the densities of PK 11195 binding sites, the extremes being 140 and 1 pmol/mg of protein in adrenal and brain tissues, respectively. There was no correlation between the relative density of PK 11195 binding sites and the specific activities of succinate dehydrogenase and cytochrome c oxidase. These results suggest that the density of peripheral-type benzodiazepine receptors in mitochondria is tissue dependent and apparently regulated independently of the mechanisms by which these two mitochondrial enzymes are expressed or function. The photoaffinity probe PK 14105 was used to photolabel the peripheral-type benzodiazepine binding sites of mitochondrial fractions prepared from the eight tissues. In all preparations, a 17,000-Da polypeptide is specifically labeled as determined by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Thus, it appears that the protein recognition site for isoquinoline carboxamides of peripheral-type benzodiazepine receptor complexes is similar in all mitochondrial preparations.
Mol Pharmacol 1988 Sep
PMID:Molecular characterization and mitochondrial density of a recognition site for peripheral-type benzodiazepine ligands. 284 47

Changes in the activity of three mitochondrial enzymes in rat liver after in vitro ischemia have been determined by enzyme histochemical methods. The changes were correlated with the appearance in the electron microscope of flocculent densities in the mitochondria indicative of irreversible cell injury. The flocculent densities were observed in rat liver after about 2 h of ischemia in vitro at 37 degrees C. At the same time the activity of glutamate dehydrogenase, localized in the mitochondrial matrix, started to decrease. However, the activities of succinate dehydrogenase localized in the inner membrane of mitochondria, as well as monoamine oxidase of the mitochondrial outer membrane did not change at that stage. It is concluded from the results of this study and those of others that flocculent densities are formed by denaturation of proteins of the mitochondrial matrix in which glutamate dehydrogenase takes part. It should be considered more as a sign than as the cause of cell death.
Virchows Arch B Cell Pathol Incl Mol Pathol 1986
PMID:A histochemical study of changes in mitochondrial enzyme activities of rat liver after ischemia in vitro. 287 57

Renal tubular lesions induced in male rats by two different carcinogens, N-nitrosomorpholine (NNM) and N-ethyl-N-hydroxyethylnitrosamine (EHEN), using a limited exposure "stop" protocol were investigated histochemically to demonstrate phenotypic cellular changes. The parameters measured included basophilia, glycogen content and the activity of the enzymes glucose-6-phosphatase (G6PASE), glycogen synthetase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphate dehydrogenase (G6PDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), succinate dehydrogenase (SDH), alkaline phosphatase (ALP), acid phosphatase (ACP) and gamma-glutamyl transpeptidase (gamma-GT). The lesions observed were predominantly of either basophilic or oncocytic types. In each case, tubular lesions (altered tubules) appeared to give rise to epithelial tumors (epitheliomas) with the same cellular phenotype. Basophilic tubules and epitheliomas proved to be strongly positive for GAPDH and G6PDH while demonstrating a reduction or loss of G6PASE, ALP, ACP, gamma-GT, and SDH compared with controls and the surrounding proximal or distal tubules. In addition, large basophilic epitheliomas demonstrated an increase in both SYN and PHO activities. In contrast, most oncocytic tubules and oncocytomas characterized by abundant densely granular cytoplasm showed a reduction in the activity of G6PDH, but were intensely positive for SDH. However, a few oncocytic lesions demonstrated a decrease in both SDH and G6PDH activity. Rarely, decreased SDH and elevated G6PDH activities were observed in altered tubules resembling oncocytic tubules. It remains to be clarified whether these tubules represent a variation of the oncocytic lesions or, perhaps, another type of tubular lesion. The results indicate that basophilic and oncocytic epithelial tumors differ in their cytochemical pattern and histogenesis. In line with earlier suggestions, the basophilic tumors apparently originate from the proximal renal tubules, while the oncocytomas develop from the distal parts of the nephron. The basophilic tumors are characterized by an increased pentose phosphate pathway and glycolysis, with a corresponding reduction in mitochondrial respiration. However, the majority of the oncocytomas show an increased activity of the mitochondrial enzyme SDH, and a marked decrease in the activity of the key enzyme of the pentose phosphate pathway.
Virchows Arch B Cell Pathol Incl Mol Pathol 1986
PMID:Correlative histochemical studies on preneoplastic and neoplastic lesions in the kidney of rats treated with nitrosamines. 287 45

Secondary lymphoid follicles in peripheral lymphoid organs (parathymic, mesenteric and inguinal lymph nodes and spleen) from young adult Wistar rats of both sexes were studied. Different numbers of tingible body macrophages containing aldehyde fuchsin-positive cytoplasmic granules of varying size, were present in the germinal centers. An identical staining pattern to that obtained with aldehyde fuchsin in terms of the number, distribution and size of positive cells was seen after staining for succinic dehydrogenase.
Virchows Arch B Cell Pathol Incl Mol Pathol 1986
PMID:Succinic dehydrogenase activity in germinal center macrophages in peripheral lymphoid organs of the rat. 288 60

The histo- and cytogenesis of two cases of renal oncocytoma have been studied by cytomorphological and cytochemical methods. Transitions from collecting ducts into oncocytic tubules were observed at the light and electron microscopic levels. The fine structure of the oncocytes in tubules and tumors is described in detail. Cytochemically, the oncocytic tubules and oncocytomas share many characteristics with the distal nephron, especially the collecting ducts. A striking difference is the enhanced activity of succinic dehydrogenase which corresponds to the increase in the number of mitochondria in oncocytes. All the results suggest that renal oncocytoma originates from the collecting duct.
Virchows Arch B Cell Pathol Incl Mol Pathol 1987
PMID:Renal oncocytoma: origin from the collecting duct. 288 61

The induction of hypothyroidism in rats by methimazole affects interscapular brown adipose tissue (IBAT) mitochondrial and peroxisomal enzyme activities in opposite directions. Hypothyroidism, indeed, decreases both mitochondrial succinate dehydrogenase and beta-oxidation total activities by 35 and 45%, respectively and increases peroxisomal catalase and acyl coenzyme A (acyl CoA) oxidase total activities 3.2- and 1.6-fold, respectively. Administration of a thyroid hormone analogue (3'-isopropyl-3,5-diiodo-L-thyronine) prevents these enzymatic modifications. The effects of hypothyroidism on IBAT mitochondrial enzyme activities seem to be direct, i.e. due to the lack of thyroid hormones, while those on peroxisomal enzyme activities might be indirect, i.e. secondary to the increased thermogenic needs of the rat and mediated by adrenergic stimulation. It is noteworthy that the indirect effects of hypothyroidism on peroxisomes are not observed in liver where acyl CoA oxidase activity is in fact decreased by 40%. In hypothyroid rat IBAT, administration of the peroxisome proliferator nafenopin does not further stimulate the already increased peroxisomal enzyme activities and does not inhibit the already decreased mitochondrial enzyme activities.
Mol Cell Endocrinol 1989 Feb
PMID:Peroxisomal oxidative capacity of brown adipose tissue depends on the thyroid status. 291 86

Lambda DNA packaging in vitro can be examined in stages. In a first step, lambda DNA interacts with terminase to form a DNA-enzyme complex, called complex I. Upon addition of proheads, in a second step, a ternary complex, complex II, containing DNA, terminase and the prohead is formed. Finally, upon addition of the rest of the morphogenetic components, complete phages are assembled. We have investigated the effect of the FI gene product (gpFI) in these reactions and found that a stimulation in phage yield is observed when gpFI is included early in the reaction, at the time when DNA, terminase and proheads interact to form complex II. Measurements of complex II formation revealed that gpFI stimulated the rate of formation of this intermediate. gpFI was further shown to stimulate the addition of proheads to preformed complexes I to give complex II, but the protein did not stimulate complex I formation.
J Mol Biol 1988 Feb 20
PMID:Bacteriophage lambda DNA packaging. The product of the FI gene promotes the incorporation of the prohead to the DNA-terminase complex. 296 51

Differences were detected between peritoneal macrophages (both resident and elicited) from mice on a low protein diet and from normal animals. The concentration of resident peritoneal macrophages was lower in animals on low protein diets than in normal controls. Although total protein (and therefore cell mass) of resident macrophages from malnourished mice was increased, their contents of thiamine pyrophosphatase, succinate dehydrogenase, and non-specific esterase were disproportionately reduced. In addition they did not ingest as many glutaraldehyde-fixed sheep erythrocytes or attach to as many adherent C3b sensitized sheep red blood cells as those from normal animals, although reduction of nitroblue tetrazolium was unaffected. Initially (24 hr after thioglycollate), elicited macrophages from malnourished mice did not divide as frequently as those from normal mice but by 48 hr the differences were insignificant. The elicited macrophage possessed lower levels of total protein (indicating a reduced cell mass); the levels of acid phosphatase, thiamine pyrophosphatase, succinate dehydrogenase, and nonspecific esterase and nitroblue reducing activity were also proportionately reduced. They ingested fewer glutaraldehyde-fixed erythrocytes and reacted with fewer C3b sensitised sheep red blood cells than those from normal mice; ingestion of IgG-coated sheep erythrocytes, on the other hand, was somewhat increased. These abnormalities may influence adversely the efficiency of early phlogistic responses and favor the establishment of infection in malnourished animals.
Exp Mol Pathol 1988 Oct
PMID:The effects of malnutrition on murine peritoneal macrophages. 297 61

The replication initiator protein of bacteriophage f1 (gene II protein) binds to the phage origin and forms two complexes that are separable by polyacrylamide gel electrophoresis. Complex I is formed at low gene II protein concentrations, and shows protection from DNase I of about 25 base-pairs (from position +2 to +28 relative to the nicking site) at the center of the minimal origin sequence. Complex II is produced at higher concentrations of the protein, and has about 40 base-pairs (from -7 to +33) protected. On the basis of gel mobility, complex II appears to contain twice the amount of gene II protein as does complex I. The 40 base-pair sequence protected in complex II corresponds to the minimal origin sequence as determined by in-vivo analyses. The central 15 base-pair sequence (from +6 to +20) of the minimal origin consists of two repeats in inverted orientation. This sequence, when cloned into a plasmid, can form complex I, but not complex II. We call this 15 base-pair element the core binding sequence for gene II protein. Methylation interference with the formation of complex I by the wild-type origin indicates that gene II protein contacts six guanine residues located in a symmetric configuration within the core binding sequence. Formation of complex II requires, in addition to the core binding sequence, the adjacent ten base-pair sequence on the right containing a third homologous repeat. A methylation interference experiment performed on complex II indicates that gene II protein interacts homologously with the three repeats. In complex II, gene II protein protects from DNase I digestion not only ten base-pairs on the right but also ten base-pairs on the left of the sequence that is protected in complex I. Footprint analyses of various deletion mutants indicate that the left-most ten base-pairs are protected regardless of their sequence. The site of nicking by gene II protein is located within this region. A model is presented for the binding reaction involving both protein-DNA and protein-protein interactions.
J Mol Biol 1987 Sep 20
PMID:Interaction between the replication origin and the initiator protein of the filamentous phage f1. Binding occurs in two steps. 350 Mar 17


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