Measurement of uridine diphosphate glucuronic acid concentrations and synthesis in animal tissues

1. A method for the isolation from animal tissues of UDP-glucuronic acid by one-dimensional paper chromatography is described and its concentrations in some tissues of several species of vertebrates are reported; the incorporation of [³²P]-phosphate into UDP-glucuronic acid in vivo was also investigated. 2. The concentration of UDP-glucuronic acid was higher in the liver of rats, rabbits and guinea pigs than in the same tissue of some species of birds, amphibia and fishes; also, the concentration of UDP-glucuronic acid in rat liver, kidney and small intestine was several times lower than that of the same tissues of guinea pigs. 3. The rate of [³²P]-phosphate incorporation into UDP-glucuronic acid was very high in rat liver and kidney and almost reached equilibrium with the radioactivity of UDP-glucose 30min after the administration of the [³²P]phosphate.     

Comparison of the requirements for ribonucleic acid synthesis with the requirements for deoxyribonucleic acid synthesis in animal tissues

Ribonucleic acid polymerase and deoxyribonucleic acid polymerase have been partially purified from bovine lymphosarcoma, lymph node, and thymus. An examination of the deoxyribonucleic acid requirements of the two enzymes indicates that “native” deoxyribonucleic acid is the preferred template for ribonucleic acid synthesis; heat-denatured deoxyribonucleic acid is considerably less active. The primer requirements for deoxyribonucleic acid synthesis differ: “native” deoxyribonucleic acid is usually inactive, while denatured deoxyribonucleic acid is active. The two enzymes also differ in pH optima and in their requirements for metal cofactors.     

N-Acyl-L-aromatic amino acid deacylase in animal tissues

An enzyme deacylating preferentially N-acyl-L-aromatic amino acids was partially purified from rat kidney. The purification procedure included DEAE-cellulose column chromatography, (NH4)2SO4 fractionation, gel-filtration on a Sephadex G-200 column and further DEAE-cellulose chromatography. The enzyme was thus separated from aminoacylase (N-acylamino-acid amidohydrolase, EC 3.5.1.14) (acylase I). Although the enzyme preparation contained other acylases, the experimental data (effect of p-chloromercuric benzoate, heat stability and inhibition between substrates) suggest that the enzyme acts preferentially on N-acyl derivatives of L-tryptophan, L-tyrosine, L-phenylalanine and L-histidine. This enzyme appears to be present in many animal tissues.