Electrophoretic fractionation of nuclear membrane proteins of the rat liver in polyacrylamide gel in the presence of sodium dodecylsulfate

1973 ◽  
Vol 75 (2) ◽  
pp. 124-127
Author(s):  
K. A. Perevoshchikova ◽  
I. V. Nochvina
Keyword(s):  
Membrane Proteins ◽  
Rat Liver ◽  
Nuclear Membrane ◽  
Sodium Dodecylsulfate ◽  
Polyacrylamide Gel ◽  
Electrophoretic Fractionation

Sorting nuclear membrane proteins at mitosis

2000 ◽  
Vol 10 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Philippe Collas ◽  
Jean-Claude Courvalin
Keyword(s):  
Membrane Proteins ◽  
Nuclear Membrane

scholarly journals Changes of nuclear membrane fluidity during rat liver regeneration

IUBMB Life ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 1049-1059 ◽  
Author(s):  
Maria-Letizia Tomassoni ◽  
Elisabetta Albi ◽  
Mariapia Viola Magani
Keyword(s):  
Liver Regeneration ◽  
Membrane Fluidity ◽  
Rat Liver ◽  
Nuclear Membrane ◽  
Rat Liver Regeneration

Purification and partial characterization of cysteine-glutamate transaminase from rat liver

1977 ◽  
Vol 55 (9) ◽  
pp. 958-964 ◽  
Author(s):  
M. P. C. Ip ◽  
R. J. Thibert ◽  
D. E. Schmidt Jr.
Keyword(s):  
Molecular Weight ◽  
Rat Liver ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Liver Homogenate ◽  
Polyacrylamide Gel ◽  
Gel Chromatography ◽  
Labile Hydrogen ◽  
Apparent Homogeneity

Cysteine-glutamate transaminase (cysteine aminotransferase; EC 2.6.1.3) has been purified 149-fold to an apparent homogeneity giving a specific activity of 2.09 IU per milligram of protein with an overall yield of 15%. The isolation procedures involve the preliminary separation of a crude rat liver homogenate which was submitted sequentially to ammonium sulfate fractionation, TEAE-cellulose column chromatography, ultrafiltration, and isoelectrofocusing. The final product was homogenous when examined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). A minimal molecular weight of 83 500 was determined by Sephadex gel chromatography. The molecular weight as estimated by polyacrylamide gel electrophoresis in the presence of SDS was 84 000. The purified enzyme exhibited a pH optimum at 8.2 with cysteine and α-ketoglutarate as substrates. The enzyme is inactivated slowly when kept frozen and is completely inactivated if left at room temperature for 1 h. The enzyme does not catalyze the transamination of α-methyl-DL-cysteine, which, when present to a final concentration of 10 mM, exhibits a 23.2% inhibition of transamination of 30 mM of cysteine. The mechanism apparently resembles that of aspartate-glutamate transaminase (EC 2.6.1.1) in which the presence of a labile hydrogen on the alpha-carbon in the substrate is one of the strict requirements.

Dissociation of the triiodothyronine receptor from the nucleus induced by cations: evidence for divalent cation sensitive and insensitive nuclear sites

1985 ◽  
Vol 110 (4) ◽  
pp. 510-514 ◽  
Author(s):  
Juan Bernal ◽  
Ana Perez-Castillo
Keyword(s):  
Rat Liver ◽  
Divalent Cation ◽  
Nuclear Membrane ◽  
Second Phase ◽  
Rat Liver Nuclei ◽  
Liver Nuclei ◽  
Fast Release

Abstract. Aliquots of purified rat liver nuclei were diluted at 0°C in isotonic buffers containing monovalent (Na+) or divalent (Ca2, Mg2+) cations. At different times following dilution the nuclear suspensions were centrifuged and the T3 receptor was measured in KCl extracts of the nuclear pellets. The rate of receptor loss after dilution in EDTA was 0.0025 min−1. Dilution in the presence of cations caused a fast release of receptor during the first 10 min. This phase, which was not observed when the nuclei were diluted in EDTA without salt, was followed by a second phase where the receptor was released at the same rate as in EDTA. Receptor release was only dependent on the presence of cations in the dilution buffer during the first 10 min after dilution. The amounts of receptor remaining in the nuclei after the first 10 min of dilution were 51.8 ± 9.2%, in the presence of Ca2+and Mg2+, 38.6 ±8.9% in 0.15 m NaCl, and 18.0 ± 4.8% in 0.15 m NaCl in the presence of Ca2+ and Mg2+. The release of receptor was not influenced by the integrity of the nuclear membrane. These results suggest the presence of divalent cation sensitive and insensitive nuclear sites for the T3 receptor, in amounts which could be estimated to be about 48 and 52%, respectively. Other interpretations are also possible, such as the presence of a high proportion of free receptors in the nucleosol, which could be released during the first phase of dilution if the negative charges in chromatin are blocked by cations to avoid redistribution of receptors immediately after dilution.

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