microsomal fraction

microsomal fraction

a collection of tiny subcellular particles, invisible with the light MICROSCOPE, that are produced during DIFFERENTIAL CENTRIFUGATION of eukaryotic cells. Under the ELECTRON MICROSCOPE, these microsomes can be seen to consist mainly of membranes and RIBOSOMES from the ENDOPLASMIC reticulum. The microsomal fraction is thus an artefact produced by the preparation process, rather than a biological entity.
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While no reactivity was observed in experiments with rat liver proteins (data not shown), a positive reaction with a protein band was observed above the 51 kD molecular weight standard in IB experiments performed with the microsomal fraction of human liver (Figure 1(c)).
Robbins (9) also reported that the first step ([omega]-hydroxylation) is carried out by the microsomal fraction of pig, dog and rat liver.
The identified enzymes involved in acetaldehyde production included alcohol dehydrogenase (ADH) and xanthine oxidoreductase (XO) in the cytosolic fraction and the flavoenzyme NADPH oxidase and catalase in the microsomal fraction [1].
The latter step yielded a pellet (Pl; mitochondria fraction), a floating particulate layer (PL; synaptosomal fraction), and an opaque supernatant (Sl; microsomal fraction, see Fig.
The prepared liver homogenate was centrifuged at 10,000g for 20min to obtain the post mitochondrial fraction which was then centrifuged at 105,000g for 60min to obtain microsomal fraction. The microsomal pellets were resuspended in 0.1 M potassium phosphate buffer, pH 7.4, containing 20% glycerol.
Each pellet was collected to determine the metal concentrations in the membranes, nuclei, "boules" (which are considered as heterolysosomes and heterophagosomes involved in intracellular digestion of cephalopods [Boucaud-Camou 1976, Boucaud-Camou & Yim 1980]) and brown bodies fraction, the mitochondrial and lysosomal fraction, and the microsomal fraction. The accuracy of the sequential separation was controlled by Transmission Electronic Microscopy after fixation in 4% glutaraldehyde and postfixation with osmium tetraoxyde in 0.4 M cacodylate buffer at pH 7.3.
The total contain of the CYP 2E1 was evaluated at the microsomal fraction from kidney and liver.
In the microsomal fraction, PH alone did not increase the rate of LP, as assessed by MDA content, but AZT enhanced this LP by-product at 6 and 72 h after surgery in animals subjected to PH, when compared to those with PH alone (Figure 5(a)).
Enzyme reaction was initiated by adding 0.5 ml of microsomal fraction and terminated after 30 min incubation, by adding 0.5 ml of 25% ice-cold ZnSO4.
(50) To clarify the issue, we prepared strains of Aspergillus oryzae in which either [alpha]- or [beta]-subunit was disrupted, and G-II activity of their microsomal fraction was tested, by using G2M9- and G1M9-MTX.