scholarly journals Endo-N-acetyl-β-D-glucosaminidase activity in rat liver. Studies on substrate specificity, enzyme inhibition, subcellular localization and partial purification

1985 ◽  
Vol 229 (2) ◽  
pp. 379-385 ◽  
Author(s):  
J J Lisman ◽  
C J van der Wal ◽  
B Overdijk
Keyword(s):  
Substrate Specificity ◽  
Subcellular Localization ◽  
Enzyme Inhibition ◽  
Rat Liver ◽  
Concanavalin A ◽  
Subcellular Distribution ◽  
Subcellular Fractions ◽  
Partial Purification ◽  
Cytoplasmic Localization

Endo-N-acetyl-beta-D-glucosaminidase (EC 3.2.1.96, endoglucosaminidase) has been partially purified (520-fold with respect to the cytoplasmic activity) by using concanavalin A-Sepharose, CM-Sephadex and Bio-Gel P-150 chromatography. From the influence of exogenous glycopeptides on the endoglucosaminidase activity it can be concluded that this activity consists of one enzyme hydrolysing both N-acetyl-lactosaminic-type and oligomannosidic-type substrates. Glycoproteins present in the homogenate inhibit the endoglucosaminidase activity. On re-examination of the subcellular distribution of endoglucosaminidase (after removal of inhibiting glycoproteins from the respective subcellular fractions), its cytoplasmic localization was confirmed.

scholarly journals Immuno-electron-microscopic studies on the subcellular distribution of rat liver epoxide hydrolase and the effect of phenobarbitone and 2-acetamidofluorene treatment

1982 ◽  
Vol 202 (3) ◽  
pp. 677-686 ◽  
Author(s):  
F Waechter ◽  
P Bentley ◽  
M Germann ◽  
F Oesch ◽  
W Stäubli
Keyword(s):  
Electron Microscopy ◽  
Rat Liver ◽  
Subcellular Distribution ◽  
Epoxide Hydrolase ◽  
Specific Binding ◽  
Subcellular Fractions ◽  
Electron Microscopic ◽  
Immuno Electron Microscopy ◽  
Microscopic Studies ◽  
The Individual

The distribution of rat liver epoxide hydrolase in various subcellular fractions was investigated by immuno-electron-microscopy. Ferritin-linked monospecific anti-(epoxide hydrolase) immunoglobulins bound specifically to the cytoplasmic surfaces of total microsomal preparations and smooth and rough microsomal fractions as well as the nuclear envelope. Specific binding was not observed when the ferritin conjugates were incubated with peroxisomes, lysosomes and mitochondria. The average specific ferritin load of the individual subcellular fractions correlated well with the measured epoxide hydrolase activities. This correlation was observed with fractions prepared from control, phenobarbitone-treated and 2-acetamidofluorene-treated rats.

scholarly journals Distribution of polypeptides binding guanosine 5′-[γ-[35S]thio]triphosphate and anti-(ras protein) antibodies in liver subcellular fractions. Evidence for endosome-specific components

1990 ◽  
Vol 271 (1) ◽  
pp. 179-183 ◽  
Author(s):  
N Ali ◽  
W H Evans
Keyword(s):  
Rat Liver ◽  
Subcellular Distribution ◽  
Plasma Membranes ◽  
Binding Proteins ◽  
Subcellular Fractions ◽  
Relative Distribution ◽  
Ras Proteins ◽  
Ras Protein ◽  
Gtp Binding Proteins ◽  
Gtp Binding

The subcellular distribution in rat liver of polypeptides binding guanosine 5′-[gamma-[35S]thio]triphosphate [( 35S]GTP[S]) and seven antibodies against ras oncoproteins was evaluated. Multiple low-Mr (21,000-28,000) GTP-binding proteins were detected, but their relative distribution among the membrane fractions varied. A more specific compartmentation of polypeptides which bind antibodies generated against ras proteins was evident, with an Mr-28,000 polypeptide and a probable Mr-56,000 dimer, identified by six of the antibodies tested, being confined mainly to endosomes. An Mr-23,000 polypeptide was detected by some of the antibodies in all of the membrane fractions, but especially in the plasma membranes.

scholarly journals Subcellular distribution of cytochrome c in rat liver. Methods for its extraction and purification

1967 ◽  
Vol 105 (2) ◽  
pp. 427-442 ◽  
Author(s):  
N. F. González-Cadavid ◽  
P. N. Campbell
Keyword(s):  
Cytochrome C ◽  
Rat Liver ◽  
Subcellular Distribution ◽  
Microsomal Fraction ◽  
Gradient Centrifugation ◽  
Ammonium Phosphate ◽  
Mitochondrial Fraction ◽  
Subcellular Fractions ◽  
Nuclear Fraction ◽  
Extraction And Purification

1. A method for the extraction and purification of cytochrome c from rat liver is described. The method depends on multiple chromatography on Amberlite IRC-50 with elution with ammonium phosphate buffers of differing ionic composition and pH, interspersed with gel filtration with Sephadex G-25. Conditions leading to denaturation are avoided and the product is chromatographically pure. 2. The method may be used for the quantitative analysis of cytochrome c either in unfractionated liver or in subcellular fractions. 3. Two pools of cytochrome c were detected, one extractable at pH4·0 with distilled water and the other extracted from the residues of the first extraction with 0·15m-sodium chloride. 4. For subcellular distribution studies the liver was homogenized in 0·3m-sucrose and a nuclear fraction (washed thoroughly to remove trapped mitochondria), a mitochondrial fraction, a heavy microsomal fraction, a standard microsomal fraction and the cell sap were isolated. The mitochondrial fraction was subfractionated further by density-gradient centrifugation. Each fraction was analysed for protein, RNA, DNA, succinate–neotetrazolium oxidoreductase and glucose 6-phosphatase. 5. A total of 123μg. of cytochrome c was obtained/g. wet wt. of rat liver. 6. Values for the percentage subcellular distribution of cytochrome c are: nuclear fraction, 24·4; mitochondrial fraction, 57·2; heavy microsomal fraction, 5·2; standard microsomal fraction, 10·6; cell sap, 2·7. 7. Three out of the eight mitochondrial subfractions separated by gradient centrifugation contained 76% of the cytochrome c and 85% of the succinate–neotetrazolium oxidoreductase present in the mitochondrial fraction. 8. In unfractionated liver 94% of the cytochrome c was extracted at pH4·0 with water whereas in most of the subcellular fractions the corresponding value was approx. 75–80%.

Subcellular localization of lodinated human kidney α-d-mannosidase in rat liver: Association with subcellular fractions in vivo and in vitro

1980 ◽  
Vol 24 (3) ◽  
pp. 327-335 ◽  
Author(s):  
Dobrivoje E. Marinkovic ◽  
Charles E. Odya ◽  
Jelka N. Marinkovic ◽  
Rajko Igic
Keyword(s):  
Subcellular Localization ◽  
Rat Liver ◽  
Human Kidney ◽  
Subcellular Fractions

scholarly journals Subcellular localization of the enzyme that forms mannosyl retinyl phosphate from guanosine diphosphate [14C]mannose and retinyl phosphate

1979 ◽  
Vol 180 (3) ◽  
pp. 449-453 ◽  
Author(s):  
M J Smith ◽  
J B Schreiber ◽  
G Wolf
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Subcellular Localization ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Subcellular Distribution ◽  
Smooth Endoplasmic Reticulum ◽  
Marker Enzymes ◽  
Guanosine Diphosphate

The subcellular distribution of the enzyme catalysing the conversion of retinyl phosphate and GDP-[14C]mannose into [14C]mannosyl retinyl phosphate was determined by using subcellular fractions of rat liver. Purity of fractions, as determined by marker enzymes, was 80% or better. The amount of mannosyl retinyl phosphate formed (pmol/min per mg of protein) for each fraction was: rough endoplasmic reticulum 0.48 +/- 0.09 (mean +/- S.D.); smooth membranes (consisting of 60% smooth endoplasmic reticulum and 40% Golgi apparatus), 0.18 +/- 0.03; Golgi apparatus, 0.13 +/- 0.03; and plasma membrane 0.02.

Acetylcholinesterase and nonspecific cholinesterase activities in rat liver: subcellular localization, molecular forms, and some extraction properties

1989 ◽  
Vol 67 (11-12) ◽  
pp. 817-822 ◽  
Author(s):  
Patricia Berninsone ◽  
Eleonora Katz ◽  
Monica Napp ◽  
Julio Azcurra
Keyword(s):  
Rat Liver ◽  
Subcellular Distribution ◽  
Ache Activity ◽  
Smooth Endoplasmic Reticulum ◽  
Subcellular Location ◽  
High Salt ◽  
Subcellular Fractions ◽  
Velocity Sedimentation ◽  
Molecular Forms ◽  
Extraction Properties

Subcellular distribution and some extraction properties of acetylcholinesterase (AchE) (EC 3.1.1.7) and nonspecific cholinesterase (ChE) (EC 3.1.1.8) were studied in rat liver employing subcellular fractionation techniques. All purified subcellular fractions were enriched in total cholinesterase activity over the homogenate. Plasma membrane and Golgi fractions showed a significant enrichment in AchE activity, while ChE activity was enriched in both rough and smooth endoplasmic reticulum. Subcellular fractions were subjected to conditions that selectively release proteins having varying degrees of association to membranes. High-pH treatment (known to release peripheral and soluble proteins) extracted ChE activity, but more than 90% of AchE activity remained associated to the pellet. Solubility properties and molecular forms of AchE and ChE in this tissue were studied by extraction in high-salt medium with and without Triton X-100, followed by velocity sedimentation centrifugation. Most of AchE activity (88%) (41% G4 and 59% G2 + G1) was detergent soluble; 42% of ChE activity (detected only as G2 + G1) was high-salt soluble, whereas remaining ChE activity was detergent soluble. These results indicate not only a different subcellular location for both enzymes, but also point to a differential association to membranes. AchE behaves as an integral membrane protein and ChE behaves as a peripheral or a luminal soluble protein.Key words: acetylcholinesterase, membrane association, molecular forms, nonspecific cholinesterase, rat liver, subcellular distribution.

Subcellular localization and substrate specificity of dolichol kinase from rat liver

1982 ◽  
Vol 719 (1) ◽  
pp. 118-125 ◽  
Author(s):  
R. Kennedy Keller ◽  
Grant D. Rottler ◽  
Nancy Cafmeyer ◽  
W. Lee Adair
Keyword(s):  
Substrate Specificity ◽  
Subcellular Localization ◽  
Rat Liver

Characterization and Partial Purification of Heterodisperse Polysomal RNAs in Normal and Neoplastic Cells

1972 ◽  
Vol 58 (2) ◽  
pp. 71-94
Author(s):  
Ada Sacchi ◽  
Gianni Chinali ◽  
Susetta Pons ◽  
Michela Galdieri ◽  
Piero Cammarano
Keyword(s):  
Size Distribution ◽  
Density Gradient ◽  
Rat Liver ◽  
Sucrose Density Gradient ◽  
Partial Purification ◽  
Messenger Rnas ◽  
Alkaline Ph ◽  
Sedimentation Profile ◽  
Molecular Weights ◽  
Phenol Extraction

The size distribution of cytoplasmic messenger RNAs (m-RNA) has been studied in rat liver and in monodifferentiated cells (mouse reticulocytes and myelomas). It has been found that the RNA which exhibits a « rapid turnover » and a polydisperse profile of radioactivity is refractory to phenol extraction. This property has been exploited to selectively isolate m–RNA from the phenol residue by means of an extraction at an alkaline pH. The sucrose density gradient profiles of m–RNA isolated from monodifferentiated cells show monodisperse peaks having the sedimentation coefficients expected on the basis of the molecular weights of monocistronic messages for α and β chains of hemoglobin (reticulocytes) and L and H chains of immunoglobulin (myelomas). The sedimentation profile of cytoplasmic m–RNA associated with rat liver polysomes shows a much broader distribution, with sedimentation coefficients ranging from 8 S to 28 S.

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