scholarly journals Detection of type-2 casein kinase and its endogenous substrates in the components of the microsomal fraction of rat liver

1984 ◽  
Vol 138 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Flavio MEGGIO ◽  
Anna Maria BRUNATI ◽  
Arianna DONELLA-DEANA ◽  
Lorenzo A. PINNA
Keyword(s):  
Rat Liver ◽  
Microsomal Fraction ◽  
Casein Kinase ◽  
Endogenous Substrates

scholarly journals Synthetic peptides including acidic clusters as substrates and inhibitors of rat liver casein kinase TS (type-2).

1984 ◽  
Vol 259 (23) ◽  
pp. 14576-14579 ◽  
Author(s):  
F Meggio ◽  
F Marchiori ◽  
G Borin ◽  
G Chessa ◽  
L A Pinna
Keyword(s):  
Rat Liver ◽  
Synthetic Peptides ◽  
Casein Kinase

Influence of 1,4-benzdiazepin-2-ones on rat liver microsomal fraction and hepatocytes

1987 ◽  
Vol 21 (1) ◽  
pp. 5-8
Author(s):  
T. I. Davidenko ◽  
O. V. Sevast'yanov ◽  
L. N. Yakubovskaya
Keyword(s):  
Rat Liver ◽  
Microsomal Fraction ◽  
Liver Microsomal Fraction

scholarly journals Loss of haem in rat liver caused by the porphyrogenic agent 2-allyl-2-isopropylacetamide

1971 ◽  
Vol 124 (4) ◽  
pp. 767-777 ◽  
Author(s):  
F. De Matteis
Keyword(s):  
Rat Liver ◽  
Microsomal Fraction ◽  
Direct Evidence ◽  
Gradual Increase ◽  
Rapid Loss ◽  
Metabolizing Enzymes ◽  
Liver Microsomal Fraction ◽  
Green Pigments ◽  
Cytochrome P 450 ◽  
Increased Activity

1. The effect of a single dose of 2-allyl-2-isopropylacetamide on the cytochrome P-450 concentration in rat liver microsomal fraction was studied. The drug caused a rapid loss of cytochrome P-450 followed by a gradual increase to above the normal concentration. 2. The loss of cytochrome P-450 was accompanied by a loss of microsomal haem and by a brown–green discoloration of the microsomal fraction suggesting that a change in the chemical constitution of the lost haem had taken place. Direct evidence for this was obtained by prelabelling the liver haems with radioactive 5-aminolaevulate: the drug caused a loss of radioactivity from the haem with an increase of radioactivity in a fraction containing certain un-identified green pigments. 3. Evidence was obtained by a dual-isotopic procedure that rapidly turning-over haem(s) may be preferentially affected. 4. The loss of cytochrome P-450 as well as the loss of microsomal haem and the discoloration of the microsomal fraction were more intense in animals pretreated with phenobarbitone and were much less evident when compound SKF 525-A (2-diethylaminoethyl 3,3-diphenylpropylacetate) was given before 2-allyl-2-isopropylacetamide, suggesting that the activity of the drug-metabolizing enzymes may be involved in these effects. 5. The relevance of the destruction of liver haem to the increased activity of 5-aminolaevulate synthetase caused by 2-allyl-2-isopropylacetamide is discussed.

scholarly journals The latency of rat liver microsomal protein disulphide-isomerase

1985 ◽  
Vol 228 (3) ◽  
pp. 635-645 ◽  
Author(s):  
N Lambert ◽  
R B Freedman
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
High Speed ◽  
Microsomal Fraction ◽  
Membrane Integrity ◽  
Microsomal Protein ◽  
Permeability Barrier ◽  
Rat Liver Microsomes ◽  
Luminal Surface ◽  
Protein Disulphide Isomerase

Protein disulphide-isomerase (PDI) activity was not detectable in freshly prepared rat liver microsomes (microsomal fraction), but became detectable after treatments that damage membrane integrity, e.g. sonication, detergent treatment or freezing and thawing. Maximum activity was detectable after sonication. Identical latency was observed in microsomes prepared by gel filtration and in those prepared by high-speed centrifugation. PDI activity was latent in all particulate subcellular fractions, but not latent in the high-speed supernatant. When all fractions were sonicated to expose total PDI activity, PDI was found at highest specific activity in the microsomal fraction and co-distributed with marker enzymes of the endoplasmic reticulum. Washing of microsomes under various conditions that removed peripheral proteins and, in some cases, bound ribosomes did not remove significant quantities of PDI, nor did it affect the latency of PDI activity. Treatment of microsomes with proteinases, under conditions where the permeability barrier of the microsomal vesicles was maintained intact, did not inactivate PDI significantly or affect its latency. PDI was very readily solubilized from microsomal vesicles by low concentrations of detergents, which removed only a fraction of the total microsomal protein. In all these respects, PDI resembled nucleoside diphosphatase, a marker peripheral protein of the luminal surface of the endoplasmic reticulum, and differed from NADPH: cytochrome c reductase, a marker integral protein exposed at the cytoplasmic surface of the membrane. The data are compatible with a model in which PDI is loosely associated with the luminal surface of the endoplasmic reticulum, a location consistent with the proposed physiological role of the enzyme as catalyst of formation of native disulphide bonds in nascent and newly synthesized secretory proteins.

scholarly journals Effects of Casein Kinase 2 Alpha 1 Gene Expression on Mice Liver Susceptible to Type 2 Diabetes Mellitus and Obesity

2020 ◽  
Vol 17 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Yu-Ching Lan ◽  
Yeh-Han Wang ◽  
Hsin-Han Chen ◽  
Sui-Foon Lo ◽  
Shih-Yin Chen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Mice Liver

Chromogenic Assays for the Determination of Prothrombin Related Material in Rat Liver Fractions.

1979 ◽  
Author(s):  
Linda J Beecroft
Keyword(s):  
Rat Liver ◽  
Vitamin K ◽  
Microsomal Fraction ◽  
Liver Homogenate ◽  
Chromogenic Substrates ◽  
Related Material ◽  
Esterolytic Activity ◽  
Echis Carinatus ◽  
Microsomal Pellet

Clotting assays are not easily applied to turbid solutions such as microsomal fractions. With the development of chromogenic substrates, the esterolytic activity of prothrombin related material can be assayed biochemically in such systems. Liver fractions were prepared by differential centrifugaron. Liver homogenate was centrifuged at 10,000 g. for 10 minutes to yield supernatant 1.Supernatant 1 was further centrifuged at 105,000 g for 60 minutes to yield the microsomal pellet and supernatant 2. Taipan and Echis carinatus snake vanoms were used to generate esterolytic activity in the various liver fractions. In all fractions the esterolytic activity generated by E. carinatus venom was greater than that generated by Taipan Venom. Both assays indicated that the microsomal pellet had similar esterolytic activity to supernatant 2. When liver fractions were prepared from warfarin treated rats, the assays revealed that the relative proportions of prothrombin related material in the fractions had altered. The esterolytic activity of the microsomal fraction was found to be greatly increased whilst supernatant 2 had no detectable activity.Warfarin treated rats have greatly decreased levels of prothrombin in the plasma due to inhibition of vitamin K-dependent carboxylation in the liver. It is suggested that the lack of prothrombin in the plasma reflects the lack of soluble prothrombin in supernatant 2, and the concomitant build-up of precursor forms bound to the microsomes.

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