Liver, calf

High riboflavin content (1000-10,000 micrograms/100 grams). Beef (kidneys, liver), calf (kidneys, liver), chicken (liver), pork (heart, kidneys, liver), sheep (kidneys, liver), yeast (killed)... 

DNA source Human thymus Sheep liver Calf thymus Herring sperm Wheat germ T2 phage... 

The three peaks have been prepared from five different sources amphibian eggs, sea urchin eggs, rat liver, calf thymus, and yeast. 

Since, as we have seen, all active RNA molecules have the same terminid sequence, pCpCpA, and tince the attachment of the amino acid occurs on the terminal adenosine, the specificity of the RNA molecules must reside in the rest of the chain. Whatever this specificity contists in, however, it does not seem to be species specific, since the activating enzymes from one source can transfer amino acids specifically to RNA s of a very different origin. Hecht and co-workers (188), for example, tiiowed that the soluble fraction from mouse ascites tumor cells could transfer amino acids to RNA prepared from rat liver, calf liver, and yeast as well as to its own RNA. The soluble enzymes from guinea pig liver can transfer amino acids to RNA from rabbit (128) and from E. coli (182), although with the latter the transfer occurs at a slower rate. Furthermore, the activating enzymes and sRNA from liver and Tetrahymena (148), and from liver and spleen (69) have also been used interchangeably. 

Double-stranded DNA (calf thymus) Single-stranded DNA Heat-denatured DNA Closed circular DNA Ribosomal RNA (rat liver)... 

The only other examples of bromoconduritol inhibition reported so far are a cytosolic jff-D-glucosidase from calf liver and the lysosomal ff-D-glu-cosidase from calf spleen. In spite of the 6500-fold difference in their reactivity with conduritol B epoxide (see Table XI), both enzymes are rapidly inactivated by bromoconduritol F, with kj(max)/Kj 10 M min for the cytosolic enzyme and lq(max)/Ki 3.2 10 for the crude and 3.9 10 M min for the purified lysosomal enzyme. It should be noted that purification of the lysosomal jS-D-glucosidase had effects on the reactivity with bromoconduritol F similar to those it had on the reactivity with conduritol B epoxide (see Table XI). 

Figure 4, Decomposition of -n-butyU t -nitrosoacetamide by calf liver RNA in phosphate buffer (pH 7) at 25°C, The dashed line is the calculated rate based on coefficients given in Table II,...

It soon became apparent that the biologically active forms of Vitamin Bj.2 contained the unique Co—C-a-bond, and the instability of these covalent compounds to visible light facilitated observations on the occurrence of functional corrinoids in a number of enzymes. Deoxyadenosyl-cobalamin was found to be the most abundant corrinoid in bacteria (24) and in mammalian liver (25). Methylcobalamin was found in Escherichia coli (26), calf liver and human blood plasma (27), and also in a number of Clostridia (28). 

Within 2 days of cessation of the low-dose-contaminated diet all calf tissues were free of famphur and famoxon this value was 4 days for the 9.9-mg/kg BW group. Concentrations of famphur (famoxon) in mg/kg FW in the high-dose group at the end of the 90-day feeding study were 0.31 (0.03) in muscle, 1.6 (0.23) in fat, 5.6 (0.5) in liver, and 0.49 (0.19) in kidney... 

Incubation mixtures containing calf thymus DNA resulted in senecionine and a related compound being bound to a macromolecular liver fraction (224). The binding of the compounds was dependent on the presence of oxygen, the enzyme system, and an NADPH-generating system, thus demonstrating that metabolites such as those formed from senecionine (Scheme 34) may interact with macromolecules to result in alkaloid-associated toxicities. 

J. H. Maguire, K. H. Dudley, Partial Purification and Characterization of Dihydro-pyrimidinases from Calf and Rat Liver , Drug Metab. Dispos. 1978, 6, 601-605. 

J. Kautz, K. D. Schnackerz, Purification and Properties of 5,6-Dihydrouracil Amino-hydrolase from Calf Liver , Eur. J. Biochem. 1989, 181, 431-435. 

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