Chicken liver

Phosphoribosyl pyrophosphate synthetase (from human erythrocytes, or pigeon or chicken liver) [9015-83-2] Mr 60,000, [EC 2.7.6.1]. Purified 5100-fold by elution from DEAE-cellulose, fractionation with ammonium sulfate, filtration on Sepharose 4B and ultrafiltration. [Fox and Kelley J Biol Chem 246 5739 197h, Flaks Methods Enzymol6 158 1963 Kornberg et al. J Biol Chem 15 389 7955.]... 

Xanthine dehydrogenase Chicken liver Purines, aldehydes NAD... 

Of the mammalian enzymes, the sulphite oxidase of bovine liver has only recently been discovered to contain molybdenum (15). The better known molybdenum enzymes, xanthine oxidase from cows milk (31) and aldehyde oxidase from rabbit liver (16) are closely related to one another as they are to the xanthine dehydrogenases from chicken liver (17) and from bacteria (18). 

Xanthine dehydrogenase from chicken liver reacts readily with NAD as acceptor (77) while that from Micrococcus lactilyticus is inactive towards this, reacting instead with ferredoxin (18). Both enzymes react only slowly with oxygen. It seems reasonable to assume, however, that for each member of this group of enzymes, reducing substrates all react via molybdenum, as in milk xanthine oxidase. Presumably, different... 

Alvear, M., Jabalquinto, A.M., and Cardemil, E. (1989) Inactivation of chicken liver mevalonate 5-diphosphate decarboxylase by sulfhydryl-directed reagents Evidence of a functional dithiol. Biochim. Biophys. Acta 994, 7-11. 

Tsukamoto, Y., and Wakil, S.J. (1988) Isolation and mapping of the b-hydroxyacyl dehydratase activity of chicken liver fatty acid synthase./. Biol. Chem. 263, 16225-16229. 

At the beginning only XO and not XDH was considered as a superoxide producer. For example, in 1985 McCord [19] suggested that the conversion of XDH into XO is responsible for an increase in superoxide production in postischemic reperfusion injury. However, it has later been shown [20,21] that XDH itself is a producer of superoxide although not so effective as XO. Moreover, the efficiency of superoxide production differs for different types of the enzyme. Thus, 2.8 to 3.0 mol of superoxide were produced by chicken liver XDH, while superoxide production by bovine milk XDH was insignificant [21]. Sanders et al. [22] found that NADH oxidation by human milk and by bovine milk XDHs catalyzed superoxide production more rapidly than XO this process was inhibited by NAD and diphenyleneiodo-nium but not by the established XO inhibitors allopurinol and oxypurinol. 

A 19-year-old female whose roommate is being treated for depression decides that she is also depressed and secretly takes her roommate s pills as directed on the bottle for several days. One night, she makes herself a snack of chicken liver pate and bleu cheese, accompanied by a glass of red wine. She soon develops headache, nausea, and palpitations. She goes to the ED, where her blood pressure is found to be 200/110 mmHg. What antidepressant did she take ... 

R. Beddell, J. N. Champness, D. K. Stammers, and J. Kraut, Refined crystal structure of Escherichia coli and chicken liver dihydrofolate reductase containing bound trimethoprim, J. Biol. Chem. 260 381 (1985). 

Ellen, G., J.W. van Loon, and K. Tolsma. 1989. Copper, chromium, manganese, nickel and zinc in kidneys of cattle, pigs and sheep and in chicken livers in the Netherlands. Zeit. Lebens. Untersuchung Forschung 189 534-537. 

Khan, S.U. and M.H. Akhtar. 1983. In vitro release of bound (nonextractable) atrazine residues from com plants by chicken liver homogenate and bovine rumen liquor. Jour. Agric. Food Chem. 31 641-644. 

Akhtar, M.H. 1983. Metabolism of fenvalerate by a chicken liver enzyme preparation. Jour. Agricul. Food Chem. 31 1080-1083. 

Extraction of nalidixic acid with chloroform from utine has also been reported.(40) Another fluorimetric method for chicken liver and muscle containing not less than 100 ppb nalidixic acid was reported by Browning(9) using an ethyl-acetate extraction and alumina column to retain the nalidixic acid. The fluorescence was measured at 325/408 nm. 

The stereospecificity of hydrogen transfer for estradiol-17 and estradiol-17(3 dehydrogenases has been examined by George et a/.84>. These enzymes are both present in chicken liver, and have substrates which differ only in the chirality of their substituents at C—17. Both of these enzymes were shown to use the 4-pro-S or 4B proton of the NADPH. Since the steroid is a bulky substrate, the authors argue that the steric fit between pyridine nucleotide and steroid cannot be as important as the role played by the enzyme in directing the fit. This paper contains an interesting summary of other recent work on the stereospecificity of pyridine nucleotide dependent-steroid dehydrogenases. 

One possible interpretation of this type of rule is the enzyme ligand binding of trimethoprim with bacterial DHFR and chicken liver DHFR. (17,18)... 

This data shows a noticeable drop in binding affinity for trimethoprim and chicken liver DHFR. Figure 8 illustrates steric interaction between the 5-OMe of trimethoprim (green) with the sidechain of Tyr 31 of native chicken liver DHFR (red). There is no steric interaction seen between the 5-OMe of trimethoprim (green) and the sidechain of Phe 30 of L. casei DHFR (red). (Right view chicken liver DHFR Left View L. casei DHFR) It is known from x-ray crystallographic results that the sidechain of Tyr 31 of chicken liver DHFR rotates to accommodate trimethoprim. ( ... 

Fig. 11 Comparison of experimental STDs (shaded circles) and calculated STD values (solid line) from CORCEMA-ST method for the crystal structure of chicken liver DHFR/TMP complex. The optimized parameters are tl =0.101 ns tp = 20.43 ns t i = 0.81 ps Tm2 = 3.04 ps Tm3 = 3.26 ps leakage factor = 0.065 and NOE R-factor = 0.076. Reprinted with permission from [75] 2005, American Chemical Society...

These three compounds exert many similar effects in nucleotide metabolism of chicks and rats [167]. They cause an increase of the liver RNA content and of the nucleotide content of the acid-soluble fraction in chicks [168], as well as an increase in rate of turnover of these polynucleotide structures [169,170]. Further experiments in chicks indicate that orotic acid, vitamin B12 and methionine exert a certain action on the activity of liver deoxyribonuclease, but have no effect on ribonuclease. Their effect is believed to be on the biosynthetic process rather than on catabolism [171]. Both orotic acid and vitamin Bu increase the levels of dihydrofolate reductase (EC 1.5.1.4), formyltetrahydrofolate synthetase and serine hydroxymethyl transferase in the chicken liver when added in diet. It is believed that orotic acid may act directly on the enzymes involved in the synthesis and interconversion of one-carbon folic acid derivatives [172]. The protein incorporation of serine, but not of leucine or methionine, is increased in the presence of either orotic acid or vitamin B12 [173]. In addition, these two compounds also exert a similar effect on the increased formate incorporation into the RNA of liver cell fractions in chicks [174—176]. It is therefore postulated that there may be a common role of orotic acid and vitamin Bj2 at the level of the transcription process in m-RNA biosynthesis [174—176]. 

One-electron reduction of chicken liver sulfite oxidase produces a species in which the molybdenum centre is Mo(V) and the b-type heme is low-spin Fe(III).90... 

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