Isolation from liver

A triokinase, isolated from liver, phosphorylates both D-glycerose and DL-glycerose, at the same rate, in the presence of adenosine-5-triphosphoric acid (ATP), and phosphorylates dihydroxyacetone at approximately half the rate.77-78... 

If 15N ammonium citrate was administered, and glutamate, aspartate, and glycine isolated from liver and intestinal wall protein, all showed 15N uptake. From the results of labeling studies, Schoenheimer finished his Edward K.Dunham lectures in Harvard in 1941 with the phrase— the structural materials [of the body] are in a steady state of flux. The classical picture must thus be replaced by one which takes account of the dynamic state of body structure —an idea which has become an integral part of biochemistry since that time, and which was almost totally dependent on the introduction of isotopes for its discovery. 

Glycogen phosphorylase isoenzymes have been isolated from liver, brain and skeletal muscle. All forms are subject to covalent control with conversion of the inactive forms (GP-b) to the active forms (GP-a) by phosphorylation on specific serine residues. This phosphorylation step, mediated by the enzyme phosphorylase kinase, is initiated by glucagon stimulation of the hepatocyte. Indeed, the same cAMP cascade which inhibits glycogen synthesis simultaneously stimulates glycogenolysis, giving us an excellent example of reciprocal control. 

Ciguatoxin (CTX) is the major chemical entity associated with ciguatera fish poisoning. CTX, a term given to the low dalton lipid by Scheuer et al. (JL) was isolated from livers of Gymnothorax obtained from an endemic area in the Pacific. A recent study by Tachibana ( 2) in Scheuer s laboratory suggests that CTX consists of numerous cyclic polyether residues similar to okadaic acid (3-5) and monensin ( ). ... 

Vitamin B12 Vitamin B12 is an important cobalt complex. The vitamin was isolated from liver after it was found that eating large quantities of raw liver was an effective treatment for pernicious anaemia. The term vitamin B12, refers to cyanocobalamin. Vitamin B12 is a coenzyme, and serves as a... 

Substrate-specificity studies on microsomal, frog-liver sialyltrans-ferase revealed the presence of (2—>3) and (2—>6) activities.277 This enzyme system readily sialylates oligosaccharides, but is almost inactive with asialofetuin, which is in contrast to the sialylation of oligosaccharides, as well as asialofetuin, by rat-liver sialyltransferase.278 The conclusion from this observation is that acceptor specificity of sialyl-transferases isolated from liver of evolutionary distant animals is similar for substrates of low molecular weight, but differs for compounds of high molecular weight.279... 

In higher plants, animals, protozoa, and fungi, saturated fatty acids are acted upon by desaturases to introduce double bonds, usually of the cis (Z) configuration. The substrates may be fatty acyl-ACP, fatty acyl-CoA molecules, membrane phospholipids,97 or glycolipids.98 The A9 desaturase, isolated from liver or from yeast, converts stearoyl-CoA to oleoyl-CoA (Eq. 21-3).99-102 This membrane-associated enzyme system... 

The liver enzyme exists in two forms, E and S, which differ only by some six residues in their amino acid sequence.13 Only the S is active toward 3-/3-hydroxysteroids, but both forms are active toward ethanol. None of the known amino acid differences is located in the subunit interfaces. Accordingly, E and S chains combine in statistical ratios to form EE, SS, and ES dimers. These different species are termed isozymes, which means that they are multiple molecular forms of the same enzyme. When it is isolated from liver, the enzyme consists of about 40 to 60% of the EE dimer, the remainder being SS and ES. 

The year of 1961, when Vincent Gott11 observed the inhibition of thrombus formation by immobilized heparin for the first time, was marked as the second birth date of heparin, since it was for the first time isolated from liver tissue. Its anticoagulant action was detected in 1892. Although more than 20 years have passed since Gott s publication, there is still much confusion concerning the views on the mechanism of enhanced thromboresistance of heparin-modified polymers, which greatly hinders the introduction of HCP into clinical practice. 

If you were interested in isolating a cDNA for human serum albumin, why would you use a cDNA library established from mRNA isolated from liver ... 

Cyanocobalamin (vitamin B12), a cobalt complex first isolated from liver but now produced commercially from microbiological culture, is needed to maintain normal synthesis of red blood cells in man and animals. Ruminants obtain cyanocobalamin from their symbiotic rumen flora while in other herbivores such as the... 

Vitamin is involved in the manufacture of the red corpuscles of the blood. It can be used for the treatment of pernicious anemia, and it is perhaps the most potent substance known in its physiological activity 1 microgram per day (1 X lO g) of vitamin B g is effective in the control of the disease. The vitamin can be isolated from liver... 

Since its isolation from liver in 1916 by McLean (M9) and the recognition of its blood anticoagulant properties, heparin has undoubtedly been the most widely studied of the acid mucopolysaccharides. Heparin has been found in many tissues, for example, liver, lung, heart, kidney, thymus, blood, and spleen. Histochemical methods have demonstrated the presence of heparin in the mast cells, which are located in connective tissues. Molecular weights of 16,000-20,000 have been suggested (M23, W6) for heparin, but many of the physical methods employed are strongly influenced by the polyelectrolyte character of the molecule. 

Derivation Isolated from liver by treatment with 30% sodium hydroxide solution. 

In general viable hepatocytes are isolated from livers or liver samples by methods based on the work by Howard et al. (7), who used an enzymatic treatment of liver slices for the dispersion of the cells. The efficiency of the method has subsequently been improved by the introduction of an in situ perfusion, that is commonly used in the case of small laboratory animals (2), and the perfusion of the liver with a buffer containing a Ca -chelator, like EGTA, prior to enzymatic treatment with collagenase (i). More recently, these methods were adapted for the isolation of hepatocytes from liver samples obtained from larger animal species, including man 5, 6). 

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