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:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine if ischemia induces alterations in renal proximal tubule surface membranes, brush border (BBM) and basolateral membranes (BLM) were isolated simultaneously from the same cortical homogenate after 50 min of renal pedicle clamping. Ischemia caused a selective decrease in the specific activity of BBM marker enzymes leucine aminopeptidase and alkaline phosphatase, but did not effect enrichment (15 times). Neither specific activity nor enrichment (10 times) of BLM NaK-ATPase was altered by ischemia. Contamination of BBM by intracellular organelles was also unchanged, but there was an increase in the specific activity (41.1 vs. 60.0, P less than 0.01) and enrichment (2.3 vs. 4.3, P less than 0.01) of NaK-ATPase in the ischemic BBM fraction. Ischemia increased BLM lysophosphatidylcholine (1.3 vs. 2.5%, P less than 0.05) and phosphatidic acid (0.4 vs. 1.3%, P less than 0.05). Ischemia also decreased BBM sphingomyelin (38.5 vs. 29.6%, P less than 0.01) and phosphatidylserine (16.1 vs. 11.4%, P less than 0.01), and increased phosphatidylcholine (17.2 vs. 29.7%, P less than 0.01), phosphatidylinositol (1.8 vs. 4.6%, P less than 0.01), and lysophosphatidylcholine (1.0 vs. 1.8%, P less than 0.05). The large changes in BBM phospholipids did not result from new phospholipid synthesis, since the specific activity (32P dpm/nmol Pi) of prelabeled individual and total phospholipids was unaltered by ischemia. We next evaluated if these changes were due to inability of ischemic cells to maintain surface membrane polarity. Cytochemical evaluation showed that while NaK-ATPase could be detected only in control BLM, specific deposits of reaction product were present in the BBM of ischemic kidneys. Furthermore, using continuous sucrose gradients, the enzymatic profile of ischemic BBM NaK-ATPase shifted away from ischemic BLM NaK-ATPase and toward the BBM enzymatic marker leucine aminopeptidase. Taken together, these data suggest that NaK-ATPase activity determined enzymatically and cytochemically was located within ischemic BBM. We propose that ischemia impairs the ability of cells to maintain surface membrane polarity, and also results in the accumulation of putative calcium ionophores.
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PMID:Ischemia induces partial loss of surface membrane polarity and accumulation of putative calcium ionophores. 300 Nov 41

Rat intestinal microvillus membrane contains at least 24 polypeptides, of which 18 can be solubilized using Triton X-114 at 4 degrees C. Upon phase separation at 32 degrees C, 11 proteins separated nearly completely into the detergent-rich phase, while 9 proteins were found exclusively in the aqueous phase. Enzymes which were uniquely included in the detergent phase were alkaline phosphatase, leucine aminopeptidase, gamma-glutamyl transpeptidase, and Ca2+-Mg2+ ATPase. The proteins which were excluded from the detergent phase and found exclusively in the aqueous phase included the disaccharidases (glucoamylase, sucrase-isomaltase, trehalase, lactase) and the ileal receptor for the intrinsic factor-cobalamin complex. Integral membrane proteins can thus be separated during solubilization into two groups prior to further purification or characterization.
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PMID:Phase separation of rat intestinal brush border membrane proteins using Triton X-114. 301 Jul 62

Controversy has recently developed over the surface distribution of Na+,K+-ATPase in hepatic parenchymal cells. We have reexamined this issue using several independent techniques. A monoclonal antibody specific for the endodomain of alpha-subunit was used to examine Na+,K+-ATPase distribution at the light and electron microscope levels. When cryostat sections of rat liver were incubated with the monoclonal antibody, followed by either rhodamine or horseradish peroxidase-conjugated goat anti-mouse secondary, fluorescent staining or horseradish peroxidase reaction product was observed at the basolateral surfaces of hepatocytes from the space of Disse to the tight junctions bordering bile canaliculi. No labeling of the canalicular plasma membrane was detected. In contrast, when hepatocytes were dissociated by collagenase digestion, Na+,K+-ATPase alpha-subunit was localized to the entire plasma membrane. Na+,K+-ATPase was quantitated in isolated rat liver plasma membrane fractions by Western blots using a polyclonal antibody against Na+,K+-ATPase alpha-subunit. Plasma membranes from the basolateral domain of hepatocytes possessed essentially all of the cell's estimated Na+,K+-ATPase catalytic activity and contained a 96-kD alpha-subunit band. Canalicular plasma membrane fractions, defined by their enrichment in alkaline phosphatase, 5' nucleotidase, gamma-glutamyl transferase, and leucine aminopeptidase had no detectable Na+,K+-ATPase activity and no alpha-subunit band could be detected in Western blots of these fractions. We conclude that Na+,K+-ATPase is limited to the sinusoidal and lateral domains of hepatocyte plasma membrane in intact liver. This basolateral distribution is consistent with its topology in other ion-transporting epithelia.
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PMID:Localization of Na+,K+-ATPase alpha-subunit to the sinusoidal and lateral but not canalicular membranes of rat hepatocytes. 303 85

Within the uterine glands, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that the activities of G-6-PDH, 6-PGDH, and cytochrome oxidase increase within secreting cells during the 2nd half of pregnancy. The activities of the other enzymes remained almost unchanged during the period of investigation. The description of our results distinguishes between gland neck, middle, and distal part of the secretory unit, respectively. In general, the enzyme activities are similar within the middle and distal gland segments, but lower in the epithelia of the neck region. The activity of dehydrogenases was medium to intensive within the middle and distal gland segments, but only low to medium within the neck portion. Of the hydrolases, the acid phosphatase, ATPase, leucine aminopeptidase, and beta-galactosidase demonstrated an intensive activity within activity secreting cells. The enzyme activities of the gland epithelia are compared with these of the uterine surface epithelia and the histochemical results are discussed in context with their significance in histiotrophic nutrition.
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PMID:[Enzyme histochemistry of the pig placenta. III. Histotopics of enzymes in the uterine epithelium]. 309 49

The 3 cases of cherubism reported affected the mandible. They were all studied by means of histo-enzymological and ultrastructural methods. This study demonstrated 3 stages in the morphological evolution of the disease, corroborated by clinical data. The 1st stage was characterized by an osteolytic granuloma with round, fusiform and giant-cells and a high level of activity of acid phosphatase. The 2nd stage showed repair with proliferation of highly active fibroblasts (increase in activity of leucine aminopeptidase). The 3rd stage exhibited an osteogenesis with high activity of alkaline phosphatase and ATPase. The pathogenesis of this rare osteodysplasia is discussed.
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PMID:Cherubism. Histo-enzymological and ultrastructural study. 313 89

We previously showed that radioactive N-ethylmaleimide injected intramuscularly reacts with actomyosin and other muscle proteins and that a transfer of these modified proteins to lysosome-rich large granules was associated with their degradation (Gerard, K. W., and Schneider, D. L., (1979) J. Biol. Chem. 254, 11798-11805). We now show that muscle cells, when challenged by an increase in proteins modified with N-ethylmaleimide, can increase degradation by increasing the activities of enzymes involved in protein turnover. Cathepsin B activity increased 2-fold 36 h after injection of N-ethylmaleimide. In contrast, non-lysosomal proteolytic enzymes, calcium-dependent protease, and leucine aminopeptidase, did not significantly increase. Lysosomes are also involved in the degradation of normal muscle proteins labeled with [3H]leucine. Treatment with chloroquine, a known inhibitor of lysosome function, resulted in an inhibition of protein degradation, in an increase of the muscle protein content, and in the accumulation of radioactive proteins in lysosomal fractions. Chloroquine treatment for 2 days led to a 270% increase in cathepsin B and a 160% increase in lysosomal ATPase activities, but only a 30% increase in neutral proteinase activities. These results indicate a role for lysosomes in regulation of protein turnover in muscle.
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PMID:Degradation of intracellular protein in muscle. Lysosomal response to modified proteins and chloroquine. 319 4

The binding characteristics of human epidermal growth factor (EGF) were compared between highly purified canalicular (CMV) and sinusoidal (basolateral) rat liver plasma membrane (SMV) preparations. The dissociation constants (2-3 nM) for these membranes were comparable, while the binding capacity for CMV was approximately half that for SMV. The binding capacity for CMV was too high to be accounted for only by the contamination with sinusoidal membranes, since the measurements of specific activities of various enzymes (Na+,K+-ATPase, alkaline phosphatase, and leucine aminopeptidase) indicated that the extents of the cross contamination with other membrane fractions were at most 10%. Although the physiological function of specific binding of EGF to bile canalicular membrane domain remains to be determined, it may have a role in biliary excretion of EGF. The specific binding of EGF to bile canalicular membranes from rat liver was identified for the first time.
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PMID:Comparison of specific binding of human epidermal growth factor (EGF) to sinusoidal and bile canalicular membranes isolated from rat liver. 326 May 89

1. Using a previously established method of isolating an active-sodium-transport inhibitor (ASTI) from hypothalamic cell culture medium, the inhibitor was isolated and partially purified from sequential passages through Sephadex G-25 and h.p.l.c., and its effects on de-endothelialized rabbit aortic strips were investigated. 2. ASTI caused a cumulative concentration-dependent increase in tension which reversed slowly after wash, and the wash showed an identical effect on fresh strips. 3. Ouabain, used as a control, also caused a concentration-dependent increase in tension which reached a plateau at a concentration of 10 mmol/l. Both ouabain and ASTI caused a significant potentiation of the vasoconstrictor effect of noradrenaline at concentrations of 1 nmol/l-0.1 mmol/l. 4. Both ASTI and ouabain caused a significantly greater (P less than 0.01) calcium retention than control medium in aortic strips. 5. Incubation of ASTI with prolidase, chymotrypsin and carboxypeptidase A destroyed the vasoconstrictor effects as well as its inhibitory effects on sodium, potassium-dependent adenosine triphosphatase and sodium efflux from erythrocytes, but leucine aminopeptidase was ineffective. 6. These studies suggest that hypothalamic cells in culture release a peptidic inhibitor of active sodium transport which increases vascular reactivity, potentiates vasoconstrictor effects of noradrenaline and causes calcium retention.
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PMID:Calcium retention and increased vascular reactivity caused by a hypothalamic sodium transport inhibitor. 340 35

The long-term effect of lithium treatment on the digestive and absorptive function has been investigated in male albino rats. The uptake of D-glucose, amino acids and activities of cellular and brush border enzymes were evaluated after every 3 months. Significantly increased uptake was observed in 6-month lithium-treated rats. The absorptive capacity (Vmax) for D-glucose increased significantly without alteration in the Michaelis constant. Activities of cellular, brush border membrane disaccharidase, leucine aminopeptidase and Na+,K+-ATPase enzymes were significantly augmented in 6-month lithium-treated animals. The elevation in sucrase activity may be due to induction of enzyme since only Vmax was increased in lithium-treated animals. The present biochemical alterations suggest that long-term lithium ingestion stimulates the small bowel digestive and absorptive functions.
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PMID:Effect of lithium ingestion on digestive and absorptive function of rat intestine. 356 79

In porcine areolar placental epithelia, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, nonspecific esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that the enzyme activities remained almost unchanged during the period of investigation. Of the dehydrogenases, the diaphorases as well as succinate and lactate dehydrogenase demonstrated generally an intensive activity within the epithelia. The activity of the other dehydrogenases was only low. The activity of unspecific esterase was very intensive within the uterine epithelia but remarkably low within chorionic epithelia. Contrarily, the reaction of adenosine triphosphatase was more intensive within chorionic than uterine epithelia. All investigated glucosidases reacted distinctly positive within chorionic epithelia, but only beta-N-acetyl-hexosaminidase and beta-galactosidase in uterine epithelia. The high activity of acid phosphatase, especially within the chorionic epithelium, seems to be connected with uteroferrin, an iron-binding protein. The histochemical results are discussed in context with the function of the areolae in histiotrophic nutrition and iron transport.
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PMID:[Enzyme-histochemical studies of the pig placenta. II. Histotopics of enzymes in the areolar placenta epithelium]. 392 41


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